From “The Conversation (AU)” : “Where did the Earth’s oxygen come from? New study hints at an unexpected source”

From “The Conversation (AU)”

11.28.22
David Mole
Postdoctoral fellow, Earth Sciences
Laurentian University

Adam Charles Simon
Arthur F. Thurnau Professor, Earth & Environmental Sciences
University of Michigan

Xuyang Meng
Postdoctoral Fellow, Earth and Environmental Sciences
University of Michigan

An artist’s impression of the Earth around 2.7 billion years ago in the Archean Eon. With green iron-rich seas, an orange methane-rich atmosphere and a surface dominated by oceans, the Archean Earth would have been a very different place. (Illustration by Andrey Atuchin), Author provided (no reuse)[Used under “Fair Use” for academic teaching purposes.]

“The amount of oxygen in the Earth’s atmosphere makes it a habitable planet.

Twenty-one per cent of the atmosphere consists of this life-giving element. But in the deep past — as far back as the Neoarchean era 2.8 to 2.5 billion years ago — this oxygen was almost absent [Science Advances (below)].

So, how did Earth’s atmosphere become oxygenated?

Our research, published in Nature Geoscience [below], adds a tantalizing new possibility: that at least some of the Earth’s early oxygen came from a tectonic source via the movement and destruction of the Earth’s crust.

The Archean Earth

The Archean eon represents one third of our planet’s history from 2.5 billion years ago to four billion years ago.

This alien Earth was a water-world, covered in green oceans, shrouded in a methane haze and completely lacking multi-cellular life. Another alien aspect of this world was the nature of its tectonic activity.

The cross-section of a subduction zone, where oceanic lithosphere slides under a continental margin. (Xuyang Meng), Author provided (no reuse)[Used under “Fair Use” for academic teaching purposes.]

On modern Earth, the dominant tectonic activity is called plate tectonics, where oceanic crust — the outermost layer of the Earth under the oceans — sinks into the Earth’s mantle (the area between the Earth’s crust and its core) at points of convergence called subduction zones.

The Tectonic Plates of the world were mapped in 1996, Geological Survey.

However, there is considerable debate over whether plate tectonics operated back in the Archean era.

One feature of modern subduction zones is their association with oxidized magmas. These magmas are formed when oxidized sediments and bottom waters — cold, dense water near the ocean floor — are introduced into the Earth’s mantle [PNAS (below)]. This produces magmas with high oxygen and water contents.

Our research aimed to test whether the absence of oxidized materials in Archean bottom waters and sediments could prevent the formation of oxidized magmas. The identification of such magmas in Neoarchean magmatic rocks could provide evidence that subduction and plate tectonics occurred 2.7 billion years ago.

The experiment

We collected samples of 2750- to 2670-million-year-old granitoid rocks from across the Abitibi-Wawa subprovince of the Superior Province — the largest preserved Archean continent stretching over 2000 km from Winnipeg, Manitoba to far-eastern Quebec. This allowed us to investigate the level of oxidation of magmas generated across the Neoarchean era.

Measuring the oxidation-state of these magmatic rocks — formed through the cooling and crystalization of magma or lava — is challenging. Post-crystallization events may have modified these rocks through later deformation, burial or heating.

So, we decided to look at the mineral apatite which is present in the zircon crystals in these rocks. Zircon crystals can withstand the intense temperatures and pressures of the post-crystallization events. They retain clues about the environments in which they were originally formed and provide precise ages for the rocks themselves.

Small apatite crystals that are less than 30 microns wide — the size of a human skin cell — are trapped in the zircon crystals. They contain sulfur. By measuring the amount of sulfur in apatite, we can establish whether the apatite grew from an oxidized magma.

Map of the Superior Province that stretches from central Manitoba to eastern Quebec in Canada. (Xuyang Meng), Author provided.

We were able to successfully measure the oxygen fugacity of the original Archean magma — which is essentially the amount of free oxygen in it — using a specialized technique called X-ray Absorption Near Edge Structure Spectroscopy (S-XANES) at the Advanced Photon Source synchrotron at The DOE’s Argonne National Laboratory in Illinois.

DOE’s Argonne National Laboratory Advanced Photo Source.

Creating oxygen from water?

We found that the magma sulfur content, which was initially around zero, increased to 2000 parts per million around 2705 million years. This indicated the magmas had become more sulfur-rich. Additionally, the predominance of S6+ — a type of sulfer ion — in the apatite [Journal of Petrology (below)] suggested that the sulfur was from an oxidized source, matching the data from the host zircon crystals [Precambrian Research (below)].

These new findings indicate that oxidized magmas did form in the Neoarchean era 2.7 billion years ago. The data show that the lack of dissolved oxygen in the Archean ocean reservoirs did not prevent the formation of sulfur-rich, oxidized magmas in the subduction zones. The oxygen in these magmas must have come from another source, and was ultimately released into the atmosphere during volcanic eruptions.

We found that the occurrence of these oxidized magmas correlates with major gold mineralization events in the Superior Province and Yilgarn Craton (Western Australia), demonstrating a connection between these oxygen-rich sources and global world-class ore deposit formation.

The implications of these oxidized magmas go beyond the understanding of early Earth geodynamics. Previously, it was thought unlikely that Archean magmas could be oxidized, when the ocean water [Science (below)] and ocean floor rocks or sediments [Nature (below)] were not.

While the exact mechanism is unclear, the occurrence of these magmas suggests that the process of subduction, where ocean water is taken hundreds of kilometres into our planet, generates free oxygen. This then oxidizes the overlying mantle.

Our study shows that Archean subduction could have been a vital, unforeseen factor in the oxygenation of the Earth, the early whiffs of oxygen 2.7 billion years ago [Nature Geoscience (below)] and also the Great Oxidation Event, which marked an increase in atmospheric oxygen by two per cent 2.45 to 2.32 billion years ago [Treatise on Geochemistry (Second Edition) (below)].

As far as we know, the Earth is the only place in the solar system — past or present — with plate tectonics and active subduction. This suggests that this study could partly explain the lack of oxygen and, ultimately, life on the other rocky planets in the future as well.”

Science papers:
PNAS 2019
Science Advances 2020
Journal of Petrology 2021
Precambrian Research 2021
See these above science papers for instructive material with images and tables.
Treatise on Geochemistry (Second Edition) 2014
Nature Geoscience 2017
Nature 2018
Science 2002
Nature Geoscience

See the full article here .

Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.

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The Conversation (AU) launched as a pilot project in October 2014. It is an independent source of news and views from the academic and research community, delivered direct to the public.
Our team of professional editors work with university and research institute experts to unlock their knowledge for use by the wider public.

Access to independent, high quality, authenticated, explanatory journalism underpins a functioning democracy. Our aim is to promote better understanding of current affairs and complex issues. And hopefully allow for a better quality of public discourse and conversation.

From “Science News” : “Here is how olivine may trigger deep earthquakes”

From “Science News”

9.26.22
Nikk Ogasa

The transformation of olivine (the yellow-green mineral seen in this rock) into wadsleyite hundreds of kilometers underground may set off the deepest earthquakes ever recorded. Credit: Joel Papalini/iStock/Getty Images Plus.

Cocooned within the bowels of the Earth, one mineral’s metamorphosis into another may trigger some of the deepest earthquakes ever detected.

These cryptic tremors — known as deep-focus earthquakes — are a seismic conundrum. They violently rupture at depths greater than 300 kilometers, where intense temperatures and pressures are thought to force rocks to flow smoothly. Now, experiments suggest that those same hellish conditions might also sometimes transform olivine — the primary mineral in Earth’s mantle — into the mineral wadsleyite. This mineral switch-up can destabilize the surrounding rock, enabling earthquakes at otherwise impossible depths, mineral physicist Tomohiro Ohuchi and colleagues report September 15 in Nature Communications [below].

“It’s been a real puzzle for many scientists because earthquakes shouldn’t occur deeper than 300 kilometers,” says Ohuchi, of Ehime University in Matsuyama, Japan.

Fig. 1: Summary of experimental conditions.

a Throughgoing faulting occurred. b No throughgoing faulting occurred. The long-dashed arrows indicate the P-T-t paths for our experiments. Squares, triangles, and diamonds represent the P-T-t path#1 (normal), #2 (overpressurized just before the deformation), and #3 (temperature ramping during the deformation), respectively. Large symbols represent the runs with throughgoing faulting (M2676, M3100, and M3425). Crosses show the lower limit of the peak temperature during the throughgoing faulting (estimated from the microstructures: see text for details). Short dashed lines are the estimated T-paths of shear heating. Red thick arrows show the temperature ranges during each deformation run of path#3. Solid and open symbols represent the runs in which the OL100 and OL92 samples were used, respectively. The equilibrium boundaries of α (olivine), β (wadsleyite), and γ (ringwoodite) for Mg1.8Fe0.2SiO4 are shown by gray solid lines14,34. Pale orange curve: solidus for dry lherzolite26. Dark-orange curve: liquidus for dry lherzolite26. Brown curve: melting of forsterite25. Pink curve: incongruent melting of γ-Fe2SiO4 to a liquid phase and stishovite (Sti)24 (i.e., the lower limit of the melting temperature of β/γ-Mg1.8Fe0.2SiO4). The M2472 run, in which a blow-out occurred in the early stage of deformation, is not shown.

Fig. 2: Summary of experimental results as a function of temperature.

a Temperature dependence of the yield strength of the samples. Creep strength of olivine (Ol) is calculated assuming the Peierls creep for sintered dry/wet aggregates15,16,17, wet dislocation (disl.) creep18 and wet dislocation-accommodated grain boundary sliding (dislGBS; for a typical grain size of 10 µm)19. Water content of 190 wt. ppm is assumed for the calculations. b Temperature dependence of averaged acoustic emission (AE) rate (symbols) and cumulative AE energy release (gray bars). Symbols and red thick-arrows are the same as those in Fig. 1. The error bars represent the uncertainties in temperature or stress.

More instructive images are available in the science paper.

Deep-focus earthquakes usually occur at subduction zones where tectonic plates made of oceanic crust — rich in olivine — plunge toward the mantle (SN: 1/13/21). Since the quakes’ seismic waves lose strength during their long ascent to the surface, they aren’t typically dangerous. But that doesn’t mean the quakes aren’t sometimes powerful. In 2013, a magnitude 8.3 deep-focus quake struck around 609 kilometers below the Sea of Okhotsk, just off Russia’s eastern coast.

Past studies [Nature Letters (below)] hinted that unstable olivine crystals could spawn deep quakes. But those studies tested other minerals that were similar in composition to olivine but deform at lower pressures, Ohuchi says, or the experiments didn’t strain samples enough to form faults.

He and his team decided to put olivine itself to the test. To replicate conditions deep underground, the researchers heated and squeezed olivine crystals up to nearly 1100° Celsius and 17 gigapascals. Then the team used a mechanical press to further compress the olivine slowly and monitored the deformation.

From 11 to 17 gigapascals and about 800° to 900° C, the olivine recrystallized into thin layers containing new wadsleyite and smaller olivine grains. The researchers also found tiny faults and recorded bursts of sound waves — indicative of miniature earthquakes. Along subducting tectonic plates, many of these thin layers grow and link to form weak regions in the rock, upon which faults and earthquakes can initiate, the researchers suggest.

“The transformation really wreaks havoc with the [rock’s] mechanical stability,” says geophysicist Pamela Burnley of the University of Nevada, Las Vegas, who was not involved in the research. The findings help confirm that olivine transformations are enabling deep-focus earthquakes, she says.

Next, Ohuchi’s team plans to experiment on olivine at even higher pressures to gain insights into the mineral’s deformation at greater depths.

Science paper:
Nature Communications
Nature Letters

See the full article here .

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From “Astronomy Magazine” : “Why does Earth have continents?”

From “Astronomy Magazine”

9.15.22
Erik Klemetti

The Tectonic Plates of the world were mapped in 1996, Geological Survey.

If you were to arrive in our solar system never having seen it before, you’d be impressed with variety. Giant gas planets with rings, moons spanning from minuscule to enormous, icy comets that hurtle in from the edges, rocky planets all with varying amounts of atmospheres. It almost seems like no two planets/moons formed the same way, but one really sticks out as an oddball.

It’s Earth. Our planet has liquid water (weird!) It has life (even weirder!) It has plate tectonics churning away (continued weirdness!) It even has gigantic masses of rocks unlike anything else in the solar system (totally weird!) Those masses are the continents, made of rocks like granite, sandstone, gneiss, slate, andesite, rhyolite and more.

The rest of the planets are almost entirely basalt or something close, but Earth. No, earth hides most of its basalt surface under deep oceans, instead letting its freak flag fly with continental rocks showing off to any passersby.

All of these unique features are connected. Plate tectonics may exist on Earth because we have liquid water at the surface. Life might be a product of the abundant water and volcanism. The composition of the Earth’s continents might be a product of life’s interactions with rock. It is all deep time evolution of minerals, rocks and organism that make Earth what it is.

What are continents anyway?

There is still a lot unknown about the formation of our continents. We’re pretty sure that no other planet has the silica-rich continental masses that Earth possesses. Mars might have a little bit of what geologists call “evolved” rocks (in other words, more silica than basalt). Venus could have a little bit as well. The Moon has anorthosite highlands that are a bit like continents except they formed from lighter minerals floating in a primordial magma ocean … that and those highlands are mostly all the same stuff.

No planet has the complex melange of volcanic rocks, sediment, metamorphic rocks and cooled magma that are Earth’s continents. The current theory, based on the ages of tiny zircon crystals found in Australia, is that our continents may have started forming over 4 billion years ago. However, whether they all formed quickly to close to their current size or have been slowly growing over time is an open question.

What makes continents so special?

Well, they are less dense and much thicker than the other flavour of plate on Earth, oceanic plates. Our ocean basins exist mainly because the crust underneath them are denser and thinner basalt plates, meaning they sit lower on the Earth’s ductile mantle (note: the Earth’s mantle is not made of molten magma). The continents, on the other hand, sit high because of their lower density and thicker profile, much like a volleyball sits higher in a pool than a tennis ball (a concept we call isostasy).

This difference does more than just create the different shapes of Earth’s surface. Continents are so buoyant that they can’t get shoved back into Earth’s mantle like the denser continental crust. Thus is born features like mountain belts formed from continental collision and subduction zones (and their volcanoes) where oceanic crust dives underneath continental crust.

The continents change as well. With plate tectonics comes the “supercontinent cycle” (also known as the Wilson Cycle) where continents collide to form massive supercontinents like Pangaea and then split apart over hundreds of millions of years. Today, the only thing we have close to a supercontinent is the amalgam of Europe, Asia and India.

The core of continents

The oldest parts of our continents are called cratons (and if those rocks are exposed at the surface, they’re called shields.) They represent the nucleus of each major continent, usually much smaller than the continent as a whole. These areas haven’t seen much in the ways of active tectonic processes like collisions or rifts for hundreds of millions to billions of years.

In North America, the craton stretches from northern Canada and Greenland (where the oldest rocks going back 3-4 billion years) to the south into Texas, but only parts of it are exposed at the surface. Most continents are more than just their cratons, so we know that the continents didn’t form all at once in the early history of the Earth. You can check out a map of the world’s cratons below to get a sense of the old cores of continents.
One of the biggest questions might be what got the whole continent thing started … and what keeps it going. It didn’t seem to happen at the other rocky planets of our solar system. This means that there are some factors that are likely intrinsic to Earth — our liquid water and molten/solid core — that helped continents develop as fully as they have. However, as they say, that’s not all.

See the full article here .

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Astronomy is a magazine about the science and hobby of Astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However, he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

From Harvard University via Science Alert(AU): “These Tiny Crystals Are ‘Time Capsules’ of Earth’s Early Plate Tectonic Activity”

From Harvard University

via

Science Alert(AU)

23 APRIL 2022
MICHELLE STARR

A large zircon crystal embedded in calcite. Credit: Rob Lavinsky/iRocks.com/Wikimedia Commons/CC BY-SA-3.0.

Tiny crystals of zircon dated to 3.8 billion years ago contain the earliest geochemical evidence yet for plate tectonic activity here on Earth.

Isotopes and trace elements preserved in the crystals show evidence that they formed under subduction conditions – when the edge of one tectonic plate slips beneath the edge of the adjacent plate, creating specific conditions. This provides new constraints on when plate tectonics emerged on Earth.

Because plate tectonics played a key role in creating the conditions for life on Earth, altering the compositions of the oceans and atmosphere, understanding when and how they emerged is also important for understanding how we got here, and what makes a planet habitable.

Understanding the geology of early Earth is something of a challenge. The crust of our world has been pretty dynamic over its 4.6-billion-year history, and the only direct record of the Hadean eon – between 4.6 and 4 billion years ago – can be found in crystals of the mineral zircon.

These crystals seem to survive the ravages of time but rarely: just 12 locations on Earth have yielded the ancient grains, three or fewer in most locations.

Recently, however, a team of geologists unearthed an amazing treasure. A chronological series of 33 microscopic zircon crystals, dating from 4.15 to 3.3 billion years ago, was found in an ancient block of Earth’s crust found in the Barberton Greenstone Belt in South Africa.

The series provided a rare opportunity to probe the changing conditions of early Earth, from the Hadean through the Eoarchaeon era, which ran from 4 to 3.6 billion years ago.

Mineral crystals can act as a sort of time capsule that contains information about the conditions in which they formed, and zircon crystals in particular can be extremely valuable for this scientific purpose. Isotopes of the metal hafnium and trace elements found in zircon can be used to make inferences about the rocks from which they crystallized.

A team of scientists led by geologist Nadja Drabon of Harvard University studied the Greenstone Belt zircons to reconstruct a timeline of the conditions under which they formed. They found that from about 3.8 billion years ago onwards, the crystals had hafnium and trace element signatures similar to modern rocks formed in subduction zones – at the edges of tectonic plates.

This suggests that plate tectonics were active at the time those crystals formed, the researchers said.

“When I say plate tectonics, I’m specifically referring to an arc setting, when one plate goes under another and you have all that volcanism – think of the Andes, for example, and the Ring of Fire,” Drabon said.

“At 3.8 billion years [ago] there is a dramatic shift where the crust is destabilized, we have new rocks forming and we see geochemical signatures becoming more and more similar to what we see in modern plate tectonics.”

Fascinatingly, zircon crystals older than that 3.8 billion-year cut-off were not formed in a subduction zone setting, but likely crystallized in a Hadean “protocrust” that formed from remelted mantle material, before the mantle was depleted of basaltic melt elements by tectonic processes.

The team then compared their findings to zircon crystals dating to around the same time from around the world to make sure they weren’t just observing a localized phenomenon. These other zircons showed similar transitions.

It’s difficult to know exactly if the tiny grains all point to the evolution of our world towards plate tectonics, but the results definitely suggest that a global change was occurring.

“We see evidence for a significant change on the Earth around 3.8 to 3.6 billion years ago and evolution toward plate tectonics is one clear possibility,” Drabon said.

“The record we have for the earliest Earth is really limited, but just seeing a similar transition in so many different places makes it really feasible that it might have been a global change in crustal processes. Some kind of reorganization was happening on Earth.”

The research has been published in AGU Advances.

See the full article here .

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Harvard University is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s bestknown landmark.

Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

The Massachusetts colonial legislature, the General Court, authorized Harvard University’s founding. In its early years, Harvard College primarily trained Congregational and Unitarian clergy, although it has never been formally affiliated with any denomination. Its curriculum and student body were gradually secularized during the 18th century, and by the 19th century, Harvard University (US) had emerged as the central cultural establishment among the Boston elite. Following the American Civil War, President Charles William Eliot’s long tenure (1869–1909) transformed the college and affiliated professional schools into a modern research university; Harvard became a founding member of the Association of American Universities in 1900. James B. Conant led the university through the Great Depression and World War II; he liberalized admissions after the war.

The university is composed of ten academic faculties plus the Radcliffe Institute for Advanced Study. Arts and Sciences offers study in a wide range of academic disciplines for undergraduates and for graduates, while the other faculties offer only graduate degrees, mostly professional. Harvard has three main campuses: the 209-acre (85 ha) Cambridge campus centered on Harvard Yard; an adjoining campus immediately across the Charles River in the Allston neighborhood of Boston; and the medical campus in Boston’s Longwood Medical Area. Harvard University’s endowment is valued at $41.9 billion, making it the largest of any academic institution. Endowment income helps enable the undergraduate college to admit students regardless of financial need and provide generous financial aid with no loans The Harvard Library is the world’s largest academic library system, comprising 79 individual libraries holding about 20.4 million items.

Harvard University has more alumni, faculty, and researchers who have won Nobel Prizes (161) and Fields Medals (18) than any other university in the world and more alumni who have been members of the U.S. Congress, MacArthur Fellows, Rhodes Scholars (375), and Marshall Scholars (255) than any other university in the United States. Its alumni also include eight U.S. presidents and 188 living billionaires, the most of any university. Fourteen Turing Award laureates have been Harvard affiliates. Students and alumni have also won 10 Academy Awards, 48 Pulitzer Prizes, and 108 Olympic medals (46 gold), and they have founded many notable companies.

Colonial

Harvard University was established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. In 1638, it acquired British North America’s first known printing press. In 1639, it was named Harvard College after deceased clergyman John Harvard, an alumnus of the University of Cambridge (UK) who had left the school £779 and his library of some 400 volumes. The charter creating the Harvard Corporation was granted in 1650.

A 1643 publication gave the school’s purpose as “to advance learning and perpetuate it to posterity, dreading to leave an illiterate ministry to the churches when our present ministers shall lie in the dust.” It trained many Puritan ministers in its early years and offered a classic curriculum based on the English university model—many leaders in the colony had attended the University of Cambridge—but conformed to the tenets of Puritanism. Harvard University has never affiliated with any particular denomination, though many of its earliest graduates went on to become clergymen in Congregational and Unitarian churches.

Increase Mather served as president from 1681 to 1701. In 1708, John Leverett became the first president who was not also a clergyman, marking a turning of the college away from Puritanism and toward intellectual independence.

19th century

In the 19th century, Enlightenment ideas of reason and free will were widespread among Congregational ministers, putting those ministers and their congregations in tension with more traditionalist, Calvinist parties. When Hollis Professor of Divinity David Tappan died in 1803 and President Joseph Willard died a year later, a struggle broke out over their replacements. Henry Ware was elected to the Hollis chair in 1805, and the liberal Samuel Webber was appointed to the presidency two years later, signaling the shift from the dominance of traditional ideas at Harvard to the dominance of liberal, Arminian ideas.

Charles William Eliot, president 1869–1909, eliminated the favored position of Christianity from the curriculum while opening it to student self-direction. Though Eliot was the crucial figure in the secularization of American higher education, he was motivated not by a desire to secularize education but by Transcendentalist Unitarian convictions influenced by William Ellery Channing and Ralph Waldo Emerson.

20th century

In the 20th century, Harvard University’s reputation grew as a burgeoning endowment and prominent professors expanded the university’s scope. Rapid enrollment growth continued as new graduate schools were begun and the undergraduate college expanded. Radcliffe College, established in 1879 as the female counterpart of Harvard College, became one of the most prominent schools for women in the United States. Harvard University (US) became a founding member of the Association of American Universities in 1900.

The student body in the early decades of the century was predominantly “old-stock, high-status Protestants, especially Episcopalians, Congregationalists, and Presbyterians.” A 1923 proposal by President A. Lawrence Lowell that Jews be limited to 15% of undergraduates was rejected, but Lowell did ban blacks from freshman dormitories.

President James B. Conant reinvigorated creative scholarship to guarantee Harvard University’s preeminence among research institutions. He saw higher education as a vehicle of opportunity for the talented rather than an entitlement for the wealthy, so Conant devised programs to identify, recruit, and support talented youth. In 1943, he asked the faculty to make a definitive statement about what general education ought to be, at the secondary as well as at the college level. The resulting Report, published in 1945, was one of the most influential manifestos in 20th century American education.

Between 1945 and 1960, admissions were opened up to bring in a more diverse group of students. No longer drawing mostly from select New England prep schools, the undergraduate college became accessible to striving middle class students from public schools; many more Jews and Catholics were admitted, but few blacks, Hispanics, or Asians. Throughout the rest of the 20th century, Harvard became more diverse.

Harvard University’s graduate schools began admitting women in small numbers in the late 19th century. During World War II, students at Radcliffe College (which since 1879 had been paying Harvard University professors to repeat their lectures for women) began attending Harvard University classes alongside men. Women were first admitted to the medical school in 1945. Since 1971, Harvard University has controlled essentially all aspects of undergraduate admission, instruction, and housing for Radcliffe women. In 1999, Radcliffe was formally merged into Harvard University.

21st century

Drew Gilpin Faust, previously the dean of the Radcliffe Institute for Advanced Study, became Harvard University’s first woman president on July 1, 2007. She was succeeded by Lawrence Bacow on July 1, 2018.

From DESY German Electron Synchrotron [Deütsches Elektronen-Synchrotron] (DE): “X-ray view of subducting tectonic plates”

From DESY German Electron Synchrotron [Deütsches Elektronen-Synchrotron] (DE)

2022/03/09

View into the Earth’s interior: The investigation conditions correspond to a depth of up to 1300 kilometres. Credit: Franziska Lorenz & Jochen Stuhrmann-illustrator/DESY.

High pressure softens the Earth’s crust in subduction zones and can detach it from the plate.

Earth’s thin crust softens considerably when it dives down into the Earth attached to a tectonic plate. That is demonstrated by X-ray studies carried out using DESY’s X-ray source PETRA III on a mineral which occurs in large quantities in basaltic crust.

DESY Petra III

This softening can even cause the crust to peel away from the underlying plate, as an international team led by Hauke Marquardt from the University of Oxford reports in the scientific journal Nature. The delaminated crust has different physical properties from the rest of the mantle, which may explain anomalies in the speed with which seismic waves propagate through the mantle.

For the first time, the scientists have managed to measure the deformation of the mineral davemaoite under the conditions that prevail inside the Earth’s mantle. “Davemaoite belongs to the widespread group of materials known as perovskites, but it is only formed from other minerals at depths of about 550 kilometres and beyond, due to the increasing pressure and temperature,” explains lead author Julia Immoor from the Bavarian Research Institute of Experimental Geochemistry and Geophysics at the University of Bayreuth. The existence of the mineral had been predicted for decades, but it was not until 2021 that a natural sample of it was found. Davemaoite differs from other perovskites in its cubic crystal structure, among other things. At great enough depths, it can account for about a quarter of the descending basaltic oceanic crust.

Using a special apparatus at DESY’s Extreme Conditions Beamline (P02.2) at PETRA III, the team has now succeeded in artificially producing davemaoite and examining it with X-rays.

The Earth’s interior in the laboratory: The sample is heated in the evacuated experimental chamber, while high pressure is applied using two ultra-hard diamond anvils. Throughout the entire process, the sample can be irradiated and analysed using PETRA III’s high-brilliancy X-ray beam. Credit: Hauke Marquardt/University of Oxford.

To do this, the scientists heated finely ground wollastonite (CaSiO3) to around 900 degrees Celsius at high pressure, until davemaoite was formed. The mineral was then deformed by applying an increasing pressure of up to 57 gigapascals – around 570,000 times atmospheric pressure at sea level – and examined using X-rays. These parameters correspond to the conditions encountered at depths of up to 1300 kilometres.

“Our measurements show that davemaoite is surprisingly soft within Earth’s lower mantle,” reports Hauke Marquardt, who led the research. “This observation completely changes our ideas about the dynamic behaviour of subducting slabs in the lower mantle.” The dynamics in these so-called subduction zones, where one tectonic plate dives underneath another, depend very much on how hard the minerals present are. Being surprisingly soft, davemaoite can cause the descending crust to detach from the underlying plate, whereby the subduction process then proceeds separately for the crust and the remaining plate.

Scientists have long speculated about such a detachment because the separated crust could cause the characteristic changes in the velocities of seismic waves that are observed at different depths. Until now, however, it has been unclear what causes could lead to such a delamination. “I am glad that the experimental setup we have come up with here is able to help solve important questions linked to processes occurring deep inside our planet,” says DESY’s Hanns-Peter Liermann, who is in charge of the Extreme Conditions Beamline at PETRA III and a co-author of the study.

Researchers from The University of Bayreuth [Universität Bayreuth](DE), Oxford and Utah, as well as from the GFZ German Research Centre for Geosciences [Deutsches Forschungszentrum für Geowissenschaften] (DE), the California Institute of Technology and DESY were involved in the study. The project was funded in part by Deutsche Forschungsgemeinschaft DFG.

See the full article here .

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DESY German Electron Synchrotron [Deütsches Elektronen-Synchrotron] (DE) is one of the world’s leading accelerator centres. Researchers use the large-scale facilities at DESY to explore the microcosm in all its variety – from the interactions of tiny elementary particles and the behaviour of new types of nanomaterials to biomolecular processes that are essential to life. The accelerators and detectors that DESY develops and builds are unique research tools. The facilities generate the world’s most intense X-ray light, accelerate particles to record energies and open completely new windows onto the universe. 
That makes DESY not only a magnet for more than 3000 guest researchers from over 40 countries every year, but also a coveted partner for national and international cooperations. Committed young researchers find an exciting interdisciplinary setting at DESY. The research centre offers specialized training for a large number of professions. DESY cooperates with industry and business to promote new technologies that will benefit society and encourage innovations. This also benefits the metropolitan regions of the two DESY locations, Hamburg and Zeuthen near Berlin.

DESY Petra III interior

DESY Petra III

DESY/FLASH

H1 detector at DESY HERA ring

DESY DORIS III

DESY LUX beamline

From The Pennsylvania State University : “Mineral dating reveals new clues about important tectonic process”

From The Pennsylvania State University

February 08, 2022
Matthew Carroll

Minerals are visible in rock samples from the coast of Oman. Scientists said these rocks may reveal new information about subduction, an important tectonic process on Earth. Credit: Joshua Garber / Penn State. Creative Commons.

Ancient rocks on the coast of Oman that were once driven deep down toward Earth’s mantle may reveal new insights into subduction, an important tectonic process that fuels volcanoes and creates continents, according to an international team of scientists.

“In a broad sense this work gives us a better understanding of why some subduction zones fail while others set up as long-term, steady-state systems,” said Joshua Garber, assistant research professor of geosciences at Penn State.

Subduction occurs when two tectonic plates collide and one is forced under the other. Where oceanic and continental plates meet, the denser oceanic plates normally subduct and descend into the mantle, the scientists said.

Occasionally, oceanic plates move on top, or obduct, forcing continental plates down toward the mantle instead. But the buoyancy of the continental crust can cause the subduction to fail, carrying the material back toward the surface along with slabs of oceanic crust and upper mantle called ophiolites, the scientists said.

“The Samail Ophiolite on the Arabian Peninsula is one of the largest and best exposed examples on the surface of the Earth,” Garber said. “It’s one of the best studied, but there have been disagreements about how and when the subduction occurred.”

The team, led by Penn State scientists, investigated the timing of the subduction using nearby rocks from the Saih Hatat formation in Oman, which was subducted under the Samail Ophiolite, according to the researchers.

Heat and pressure from the process created garnet, zircon and rutile crystals in a key suite of highly metamorphosed rocks that saw the most extreme conditions during subduction. Using state-of-the-art dating techniques, including measuring isotopic dates and trace elements, the scientists determined these minerals all formed at roughly the same time 81 to 77 million years ago.

“What’s interesting about this is that they were all dated by slightly different methods, but they all gave us essentially the same results,” Garber said. “This tells us that all the minerals in the rocks have a coherent story. They all record the same metamorphic episode at the same time.”

The findings, published in the Journal of Geophysical Research: Solid Earth, dispute previous results that estimated the event began 110 million years ago and happened in separate phases, the scientists said.

“What our findings suggest is that this continental material was not subducted deep into the mantle a long time before the ophiolite formed as previously thought,” Garber said. “Our data supports a nice sequence of events that happened in a tighter window and that makes more geological sense.”

The scientists said the subduction of the continental margin occurred after the obduction of the Samail Ophiolite. The most deeply subducted continental material was likely anchored to more dense rocks, and when this anchor broke, the buoyant continental rocks exhumed, first quickly, and then slowly during a lengthy residence in the lower to middle crust. It eventually become exposed in tectonic windows through the ophiolite.

“Subduction is a really big part of plate tectonics on Earth,” Garber said. “It’s the major recycling mechanism for surface material to the deeper mantle, so understanding how they eventually evolve into stable subduction zones or how they end very quickly is of great interest. I think here we’ve nailed down why this subduction zone ended and the sequence of events that came with it.”

Also contributing to this work from Penn State was Andrew Smye, assistant professor of geosciences.

Matthew Rioux, assistant teaching professor, Bradley Hacker, professor emeritus, and Andrew Kylander-Clark, senior development engineer, at the University of California- Santa Barbara; Michael Searle, professor at The University of Oxford (UK); Jeff Vervoort, professor at The Washington State University (US); and Clare Warren, professor at The Open University(UK) also contributed.

See the full article here .

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The The Pennsylvania State University is a public state-related land-grant research university with campuses and facilities throughout Pennsylvania. Founded in 1855 as the Farmers’ High School of Pennsylvania, Penn State became the state’s only land-grant university in 1863. Today, Penn State is a major research university which conducts teaching, research, and public service. Its instructional mission includes undergraduate, graduate, professional and continuing education offered through resident instruction and online delivery. In addition to its land-grant designation, it also participates in the sea-grant, space-grant, and sun-grant research consortia; it is one of only four such universities (along with Cornell University, Oregon State University, and University of Hawaiʻi at Mānoa). Its University Park campus, which is the largest and serves as the administrative hub, lies within the Borough of State College and College Township. It has two law schools: Penn State Law, on the school’s University Park campus, and Dickinson Law, in Carlisle. The College of Medicine is in Hershey. Penn State is one university that is geographically distributed throughout Pennsylvania. There are 19 commonwealth campuses and 5 special mission campuses located across the state. The University Park campus has been labeled one of the “Public Ivies,” a publicly funded university considered as providing a quality of education comparable to those of the Ivy League.

Annual enrollment at the University Park campus totals more than 46,800 graduate and undergraduate students, making it one of the largest universities in the United States. It has the world’s largest dues-paying alumni association. The university offers more than 160 majors among all its campuses.

Annually, the university hosts the Penn State IFC/Panhellenic Dance Marathon (THON), which is the world’s largest student-run philanthropy. This event is held at the Bryce Jordan Center on the University Park campus. The university’s athletics teams compete in Division I of the NCAA and are collectively known as the Penn State Nittany Lions, competing in the Big Ten Conference for most sports. Penn State students, alumni, faculty and coaches have received a total of 54 Olympic medals.

Early years

The school was sponsored by the Pennsylvania State Agricultural Society and founded as a degree-granting institution on February 22, 1855, by Pennsylvania’s state legislature as the Farmers’ High School of Pennsylvania. The use of “college” or “university” was avoided because of local prejudice against such institutions as being impractical in their courses of study. Centre County, Pennsylvania, became the home of the new school when James Irvin of Bellefonte, Pennsylvania, donated 200 acres (0.8 km2) of land – the first of 10,101 acres (41 km^2) the school would eventually acquire. In 1862, the school’s name was changed to the Agricultural College of Pennsylvania, and with the passage of the Morrill Land-Grant Acts, Pennsylvania selected the school in 1863 to be the state’s sole land-grant college. The school’s name changed to the Pennsylvania State College in 1874; enrollment fell to 64 undergraduates the following year as the school tried to balance purely agricultural studies with a more classic education.

George W. Atherton became president of the school in 1882, and broadened the curriculum. Shortly after he introduced engineering studies, Penn State became one of the ten largest engineering schools in the nation. Atherton also expanded the liberal arts and agriculture programs, for which the school began receiving regular appropriations from the state in 1887. A major road in State College has been named in Atherton’s honor. Additionally, Penn State’s Atherton Hall, a well-furnished and centrally located residence hall, is named not after George Atherton himself, but after his wife, Frances Washburn Atherton. His grave is in front of Schwab Auditorium near Old Main, marked by an engraved marble block in front of his statue.

Early 20th century

In the years that followed, Penn State grew significantly, becoming the state’s largest grantor of baccalaureate degrees and reaching an enrollment of 5,000 in 1936. Around that time, a system of commonwealth campuses was started by President Ralph Dorn Hetzel to provide an alternative for Depression-era students who were economically unable to leave home to attend college.

In 1953, President Milton S. Eisenhower, brother of then-U.S. President Dwight D. Eisenhower, sought and won permission to elevate the school to university status as The Pennsylvania State University. Under his successor Eric A. Walker (1956–1970), the university acquired hundreds of acres of surrounding land, and enrollment nearly tripled. In addition, in 1967, the Penn State Milton S. Hershey Medical Center, a college of medicine and hospital, was established in Hershey with a $50 million gift from the Hershey Trust Company.

Modern era

In the 1970s, the university became a state-related institution. As such, it now belongs to the Commonwealth System of Higher Education. In 1975, the lyrics in Penn State’s alma mater song were revised to be gender-neutral in honor of International Women’s Year; the revised lyrics were taken from the posthumously-published autobiography of the writer of the original lyrics, Fred Lewis Pattee, and Professor Patricia Farrell acted as a spokesperson for those who wanted the change.

In 1989, the Pennsylvania College of Technology in Williamsport joined ranks with the university, and in 2000, so did the Dickinson School of Law. The university is now the largest in Pennsylvania. To offset the lack of funding due to the limited growth in state appropriations to Penn State, the university has concentrated its efforts on philanthropy.

Research

Penn State is classified among “R1: Doctoral Universities – Very high research activity”. Over 10,000 students are enrolled in the university’s graduate school (including the law and medical schools), and over 70,000 degrees have been awarded since the school was founded in 1922.

Penn State’s research and development expenditure has been on the rise in recent years. For fiscal year 2013, according to institutional rankings of total research expenditures for science and engineering released by the National Science Foundation (US), Penn State stood second in the nation, behind only Johns Hopkins University (US) and tied with the Massachusetts Institute of Technology (US), in the number of fields in which it is ranked in the top ten. Overall, Penn State ranked 17th nationally in total research expenditures across the board. In 12 individual fields, however, the university achieved rankings in the top ten nationally. The fields and sub-fields in which Penn State ranked in the top ten are materials (1st), psychology (2nd), mechanical engineering (3rd), sociology (3rd), electrical engineering (4th), total engineering (5th), aerospace engineering (8th), computer science (8th), agricultural sciences (8th), civil engineering (9th), atmospheric sciences (9th), and earth sciences (9th). Moreover, in eleven of these fields, the university has repeated top-ten status every year since at least 2008. For fiscal year 2011, the National Science Foundation reported that Penn State had spent $794.846 million on R&D and ranked 15th among U.S. universities and colleges in R&D spending.

For the 2008–2009 fiscal year, Penn State was ranked ninth among U.S. universities by the National Science Foundation, with $753 million in research and development spending for science and engineering. During the 2015–2016 fiscal year, Penn State received $836 million in research expenditures.

The Applied Research Lab (ARL), located near the University Park campus, has been a research partner with the Department of Defense (US) since 1945 and conducts research primarily in support of the United States Navy. It is the largest component of Penn State’s research efforts statewide, with over 1,000 researchers and other staff members.

The Materials Research Institute was created to coordinate the highly diverse and growing materials activities across Penn State’s University Park campus. With more than 200 faculty in 15 departments, 4 colleges, and 2 Department of Defense research laboratories, MRI was designed to break down the academic walls that traditionally divide disciplines and enable faculty to collaborate across departmental and even college boundaries. MRI has become a model for this interdisciplinary approach to research, both within and outside the university. Dr. Richard E. Tressler was an international leader in the development of high-temperature materials. He pioneered high-temperature fiber testing and use, advanced instrumentation and test methodologies for thermostructural materials, and design and performance verification of ceramics and composites in high-temperature aerospace, industrial, and energy applications. He was founding director of the Center for Advanced Materials (CAM), which supported many faculty and students from the College of Earth and Mineral Science, the Eberly College of Science, the College of Engineering, the Materials Research Laboratory and the Applied Research Laboratories at Penn State on high-temperature materials. His vision for Interdisciplinary research played a key role in creating the Materials Research Institute, and the establishment of Penn State as an acknowledged leader among major universities in materials education and research.

The university was one of the founding members of the Worldwide Universities Network (WUN), a partnership that includes 17 research-led universities in the United States, Asia, and Europe. The network provides funding, facilitates collaboration between universities, and coordinates exchanges of faculty members and graduate students among institutions. Former Penn State president Graham Spanier is a former vice-chair of the WUN.

The Pennsylvania State University Libraries were ranked 14th among research libraries in North America in the 2003–2004 survey released by The Chronicle of Higher Education. The university’s library system began with a 1,500-book library in Old Main. In 2009, its holdings had grown to 5.2 million volumes, in addition to 500,000 maps, five million microforms, and 180,000 films and videos.

The university’s College of Information Sciences and Technology is the home of CiteSeerX, an open-access repository and search engine for scholarly publications. The university is also the host to the Radiation Science & Engineering Center, which houses the oldest operating university research reactor. Additionally, University Park houses the Graduate Program in Acoustics, the only freestanding acoustics program in the United States. The university also houses the Center for Medieval Studies, a program that was founded to research and study the European Middle Ages, and the Center for the Study of Higher Education (CSHE), one of the first centers established to research postsecondary education.

From Science Alert (AU): “Mountain-Sized Rock Hidden Underneath Japan Could Be a Magnet For Megaquakes”

From Science Alert (AU)

8 FEBRUARY 2022
MICHELLE STARR

A mountain-sized mass of igneous rock beneath the coast of southern Japan could be acting as a sort of magnet or lightning rod for huge earthquakes.

The Kumano Pluton appears as a red bulge (indicating dense rock) in the 3D visualization. Credit: Adrien Arnulf.

According to a new 3D visualization of the feature, known as the Kumano Pluton, the tectonic energy from megaquakes seems to be diverted to several points along its side.

This could help scientists better predict the impact of massive quakes in the region, as well as better understand how these igneous masses interact with tectonic activity.

“We cannot predict exactly when, where, or how large future earthquakes will be, but by combining our model with monitoring data, we can begin estimating near-future processes,” says geophysicist Shuichi Kodaira of the JAMSTEC – JAPAN AGENCY FOR MARINE-EARTH SCIENCE AND TECHNOLOGY [国立研究開発法人海洋研究開発機構](JP) in Japan.

“That will provide very important data for the Japanese public to prepare for the next big earthquake.”

Hints of the Kumano Pluton were first revealed in 2006. It is, as the name suggests, a rock feature known as a pluton – an intrusion of igneous rock that displaces rock underground, slowly cooling and hardening in a large chunk.

Seismic imaging revealed that there was something of a different density to the surrounding rock on the Nankai subduction zone; that’s the region along which one tectonic plate slips beneath the edge of another, accompanied by heightened earthquake and volcanic activity. Numerical simulations helped reveal that the chunk was plutonic.

But the true extent of it remained unexplored. Now, using 20 years’ worth of seismic data from the Nankai subduction zone, a team of researchers has mapped the entirety of the Kumano Pluton.

Quakes and tremors, while destructive, can also be a very powerful tool, you see. Quakes are quite marvelous things, really. They ripple out from their point of origin, propagating through the planet, and bouncing around.

The way these seismic waves travel through and reflect off certain materials allows seismologists to map structures we can’t see deep underground.

It was painstaking work, comprising not just the millions of seismic recordings from Japan’s network of earthquake sensors, but also those of other passing scientific surveys, for the largest seismic data set ever created.

The vast amount of data the team compiled on the Nankai subduction zone was fed into the LoneStar5 supercomputer at the University of Texas at Austin to generate a high-resolution 3D model of the pluton.

Fascinatingly, it revealed features we hadn’t seen before.

TACC Lonestar Cray XC40 supercomputer.

The model shows that the pluton’s weight is causing Earth’s crust beneath it to bend under the strain, and bulge upward slightly above it. Surprisingly, the pluton seems to be providing a pathway for groundwater to seep beneath Earth’s crust into the upper mantle by exacerbating the bending of Earth’s crust.

Cross section showing the origin of the 1944 quake. Credit: Arnulf et al., Nat.Commun., 2022.

Because the Kumano Pluton is so dense and rigid, it is also likely playing a significant role in tectonic activity.

Huge earthquakes with magnitudes higher than 8 originated on the flanks of the pluton in 1944 and 1946. Given that subducting slabs are highly sensitive to variations in structure, the pluton is likely having a profound effect on both the geometry and tectonic activity in the region.

The team hopes that their discovery will prompt thorough investigations into the subterranean structures that might be hiding in other subduction zones.

“The fact that we can make such a large discovery in an area that is already well studied is, I think, eye opening to what might await at places that are less well monitored,” says geophysicist Adrien Arnulf of the University of Texas Institute for Geophysics.

The research has been published in naturegeoscience.

See the full article here .

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From The Massachusetts Institute of Technology (US)Department of Earth, Atmosphere, and Planetary Sciences: “Shaking up earthquake research at MIT”

M.I.T. Department of Earth, Atmosphere, and Planetary Sciences

at

The Massachusetts Institute of Technology (US)

February 4, 2022
Lauren Hinkel – M.I.T. Department of Earth Atmosphere and Planetary Sciences

Landsat 8 captured this view of the folded rock landscape of Morocco’s Anti-Atlas Mountains, formed by the slow-motion collision of the African and Eurasian tectonic Photo: Geological Survey (US)/The National Aeronautics Space Agency(US).

NASA Landsat 8.

Major environmental events write their own headlines. With loss of life and crippling infrastructure damage, the aftershocks of earthquakes reverberate around the world — not only as seismic waves, but also in the photos and news stories that follow a major seismic event. So, it is no wonder that both scientists and the public are keen to understand the dynamics of faults and their hazard potential, with the ultimate goal of prediction.

To do this, William Frank and Camilla Cattania, assistant professors in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS), have teamed up as EQSci@MIT to uncover hidden earthquake behaviors and fault complexity, through observation, statistics, and modeling. Together, their complementary avenues of research are helping to expose the fault mechanics underpinning everything from aseismic events, like slow slip actions that occur over periods of hours or months, to large magnitude earthquakes that strike in seconds. They’re also looking at the ways tectonic regions interact with neighboring events to better understand how faults and seismic events evolve — and, in the process, shedding light on how frequently and predictably these events might occur.

“Basically, [we’re] trying to build together a pipeline from observations through modeling to answer the big-picture questions,” says Frank. “When we actually observe something, what does that mean for the big-picture result, in places where we have strong heterogeneity and lots of earthquake activity?”

Observing Earth as it creeps

While there are many ways to investigate different types of earthquakes and faults, Frank takes a detailed and steady approach: looking at slow-moving, low wave frequency earthquakes — called slow slip — in subduction zones over long periods of time. These events tend to go unnoticed by the public and lack an obvious seismic wave signature that would be registered by seismometers. However, they play a significant role in tectonic buildup and release of energy. “When we start to look at the size of these slow slip events, we realize that they are just as big as earthquakes,” says Frank.

His group leverages geodetic data, like GPS, to monitor how the ground moves on and near a fault to reveal what’s happening along the plate interface as you descend deeper underground. In the crust near the surface the plates tend to be locked together along the boundary building up pressure and then releasing it as a giant earthquake. However, below that region, Frank says, the rocks are more elastic and can deform and creep, which can be picked up on instrumentation. “There are events that are transient. They happen over a set period of time, just like an earthquake, but instead of several seconds to minutes, they last several days to months,” he says.

Since slow slip has the capacity to cause energy loading in subduction zones through both stress and release, Frank and his group want to understand how slow earthquakes interact with seismic regions, where there’s potential for a large earthquake. By digging into observational data, from long-term readings to those taken on the scale of a few hours, Frank has learned that often there are many tiny earthquakes that repeat during slow slip. While a first glance at the data may look like just noise, clear signals emerge on closer inspection that reveal a lot about the subsurface plate interface — like the presence of trapped fluid, and how subduction zones behave at different locations along a fault.

“If we really want to understand where and when and how we’re going to have a big earthquake, you have to understand what’s happening around it,” says Frank, who has projects spread out around the globe, investigating subducting plate boundaries from Japan to the Pacific Northwest, and all the way to Antarctica.

The Ring of Fire via Wikimedia Commons.

Modeling complexity

Camilla Cattania’s work provides a counterpoint for Frank’s. Where the Frank group incorporates seismic and geodetic record collection, Cattania employs numerical, analytical, and statistical tools to understand the physics of earthquakes. Through modeling, her team can test hypotheses and then look for corroborating evidence in the field, or vice versa, using collected data to inform and refine models. Influenced by major seismic hazards in her home country of Italy, Cattania is keenly interested in the potential to contribute models for practical use in earthquake forecasting.

One aspect of her work has been to reconcile theoretical models with the complex reality of fault geometry. Each fault has its own physical characteristics that affect its behavior and can evolve over time — not just the dimensions of the fault, but also factors like the orientation of the rock fractures, the elastic properties of the rocks, and the irregularity and roughness of their surfaces. When looking into numerical models of aftershock sequences, she was able to show that they weren’t as predictive as statistical models because previous models were using idealized fault planes in the calculations.

To remedy this, Cattania explored ways to incorporate fault geometry that’s more consistent with the complexity found in nature. “We were the first to implement this in a systematic way and then compare it to statistical models, and … to show that these physical models can do well, if you make them realistic enough,” she says.

Cattania has also been looking into modeling how the physical properties of faults control the frequency and size of earthquakes — a key question in understanding the hazards they pose. Some earthquake sequences tend to recur at intervals, but most don’t, defying easy prediction. In trying to understand why this is, Cattania explains, size is everything. “It turns out that periodicity is a property which depends on the size of the earthquake. It’s much more unlikely to get periodic behavior for a large earthquake than it is for a small one, and it just comes out of the fundamental physics of how friction and elasticity control the cycle,” she says.

A synergistic approach

Ultimately, through their collaboration in EAPS at MIT, Frank and Cattania are trying to build more communication between observation and modeling in order to foster more rapid advancements in earthquake science. “Ever-improving seismic and geodetic measurements together with new data analysis techniques are providing unprecedented opportunities to probe fault behavior,” says Cattania. “With numerical models and theory, we try to explain why faults slip the way they do, and the best way to make progress is for modelers and observationalists to talk to each other.”

“What I really like about observational geophysics, and for my science to be useful, is collaborating and interacting with many different people,” says Frank. “Part of that is bringing together the different observational approaches and the constraints that we can generate, and [then] communicating our results to the modelers. More often than not, there’s not as much communication as we’d like [between the groups]; so I’m super excited about Camilla being here.”

_____________________________________________________________________________________

Earthquake Alert

Earthquake Alert

Earthquake Network project is a research project which aims at developing and maintaining a crowdsourced smartphone-based earthquake warning system at a global level. Smartphones made available by the population are used to detect the earthquake waves using the on-board accelerometers. When an earthquake is detected, an earthquake warning is issued in order to alert the population not yet reached by the damaging waves of the earthquake.

The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.

Get the app in the Google Play store.

Smartphone network spatial distribution (green and red dots) on December 4, 2015

Meet The Quake-Catcher Network

Quake-Catcher Network

The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

There are two categories of sensors used by QCN: 1) internal mobile device sensors, and 2) external USB sensors.

Mobile Devices: MEMS sensors are often included in laptops, games, cell phones, and other electronic devices for hardware protection, navigation, and game control. When these devices are still and connected to QCN, QCN software monitors the internal accelerometer for strong new shaking. Unfortunately, these devices are rarely secured to the floor, so they may bounce around when a large earthquake occurs. While this is less than ideal for characterizing the regional ground shaking, many such sensors can still provide useful information about earthquake locations and magnitudes.

USB Sensors: MEMS sensors can be mounted to the floor and connected to a desktop computer via a USB cable. These sensors have several advantages over mobile device sensors. 1) By mounting them to the floor, they measure more reliable shaking than mobile devices. 2) These sensors typically have lower noise and better resolution of 3D motion. 3) Desktops are often left on and do not move. 4) The USB sensor is physically removed from the game, phone, or laptop, so human interaction with the device doesn’t reduce the sensors’ performance. 5) USB sensors can be aligned to North, so we know what direction the horizontal “X” and “Y” axes correspond to.

If you are a science teacher at a K-12 school, please apply for a free USB sensor and accompanying QCN software. QCN has been able to purchase sensors to donate to schools in need. If you are interested in donating to the program or requesting a sensor, click here.

BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

Below, the QCN Quake Catcher Network map

ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States

The U. S. Geological Survey (USGS) along with a coalition of State and university partners is developing and testing an earthquake early warning (EEW) system called ShakeAlert for the west coast of the United States. Long term funding must be secured before the system can begin sending general public notifications, however, some limited pilot projects are active and more are being developed. The USGS has set the goal of beginning limited public notifications in 2018.

Watch a video describing how ShakeAlert works in English or Spanish.

The primary project partners include:

United States Geological Survey
California Governor’s Office of Emergency Services (CalOES)
California Geological Survey
California Institute of Technology
University of California Berkeley
University of Washington
University of Oregon
Gordon and Betty Moore Foundation

The Earthquake Threat

Earthquakes pose a national challenge because more than 143 million Americans live in areas of significant seismic risk across 39 states. Most of our Nation’s earthquake risk is concentrated on the West Coast of the United States. The Federal Emergency Management Agency (FEMA) has estimated the average annualized loss from earthquakes, nationwide, to be $5.3 billion, with 77 percent of that figure ($4.1 billion) coming from California, Washington, and Oregon, and 66 percent ($3.5 billion) from California alone. In the next 30 years, California has a 99.7 percent chance of a magnitude 6.7 or larger earthquake and the Pacific Northwest has a 10 percent chance of a magnitude 8 to 9 megathrust earthquake on the Cascadia subduction zone.

Part of the Solution

Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of the ShakeAlert system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. This can be done by detecting the first energy to radiate from an earthquake, the P-wave energy, which rarely causes damage. Using P-wave information, we first estimate the location and the magnitude of the earthquake. Then, the anticipated ground shaking across the region to be affected is estimated and a warning is provided to local populations. The method can provide warning before the S-wave arrives, bringing the strong shaking that usually causes most of the damage.

Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds. ShakeAlert can give enough time to slow trains and taxiing planes, to prevent cars from entering bridges and tunnels, to move away from dangerous machines or chemicals in work environments and to take cover under a desk, or to automatically shut down and isolate industrial systems. Taking such actions before shaking starts can reduce damage and casualties during an earthquake. It can also prevent cascading failures in the aftermath of an event. For example, isolating utilities before shaking starts can reduce the number of fire initiations.

System Goal

The USGS will issue public warnings of potentially damaging earthquakes and provide warning parameter data to government agencies and private users on a region-by-region basis, as soon as the ShakeAlert system, its products, and its parametric data meet minimum quality and reliability standards in those geographic regions. The USGS has set the goal of beginning limited public notifications in 2018. Product availability will expand geographically via ANSS regional seismic networks, such that ShakeAlert products and warnings become available for all regions with dense seismic instrumentation.

Current Status

The West Coast ShakeAlert system is being developed by expanding and upgrading the infrastructure of regional seismic networks that are part of the Advanced National Seismic System (ANSS); the California Integrated Seismic Network (CISN) is made up of the Southern California Seismic Network, SCSN) and the Northern California Seismic System, NCSS and the Pacific Northwest Seismic Network (PNSN). This enables the USGS and ANSS to leverage their substantial investment in sensor networks, data telemetry systems, data processing centers, and software for earthquake monitoring activities residing in these network centers. The ShakeAlert system has been sending live alerts to “beta” users in California since January of 2012 and in the Pacific Northwest since February of 2015.

In February of 2016 the USGS, along with its partners, rolled-out the next-generation ShakeAlert early warning test system in California joined by Oregon and Washington in April 2017. This West Coast-wide “production prototype” has been designed for redundant, reliable operations. The system includes geographically distributed servers, and allows for automatic fail-over if connection is lost.

This next-generation system will not yet support public warnings but does allow selected early adopters to develop and deploy pilot implementations that take protective actions triggered by the ShakeAlert notifications in areas with sufficient sensor coverage.

Authorities

The USGS will develop and operate the ShakeAlert system, and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program, as enacted by the Earthquake Hazards Reduction Act of 1977, 42 U.S.C. §§ 7704 SEC. 2.

For More Information

Robert de Groot, ShakeAlert National Coordinator for Communication, Education, and Outreach
rdegroot@usgs.gov
626-583-7225

Learn more about EEW Research

ShakeAlert Fact Sheet

ShakeAlert Implementation Plan

QuakeAlertUSA

About Early Warning Labs, LLC

Early Warning Labs, LLC (EWL) is an Earthquake Early Warning technology developer and integrator located in Santa Monica, CA. EWL is partnered with industry leading GIS provider ESRI, Inc. and is collaborating with the US Government and university partners.

EWL is investing millions of dollars over the next 36 months to complete the final integration and delivery of Earthquake Early Warning to individual consumers, government entities, and commercial users.

EWL’s mission is to improve, expand, and lower the costs of the existing earthquake early warning systems.

EWL is developing a robust cloud server environment to handle low-cost mass distribution of these warnings. In addition, Early Warning Labs is researching and developing automated response standards and systems that allow public and private users to take pre-defined automated actions to protect lives and assets.

EWL has an existing beta R&D test system installed at one of the largest studios in Southern California. The goal of this system is to stress test EWL’s hardware, software, and alert signals while improving latency and reliability.

Earthquake Early Warning Introduction

The United States Geological Survey (USGS), in collaboration with state agencies, university partners, and private industry, is developing an earthquake early warning system (EEW) for the West Coast of the United States called ShakeAlert. The USGS Earthquake Hazards Program aims to mitigate earthquake losses in the United States. Citizens, first responders, and engineers rely on the USGS for accurate and timely information about where earthquakes occur, the ground shaking intensity in different locations, and the likelihood is of future significant ground shaking.

The ShakeAlert Earthquake Early Warning System recently entered its first phase of operations. The USGS working in partnership with the California Governor’s Office of Emergency Services (Cal OES) is now allowing for the testing of public alerting via apps, Wireless Emergency Alerts, and by other means throughout California.

ShakeAlert partners in Oregon and Washington are working with the USGS to test public alerting in those states sometime in 2020.

ShakeAlert has demonstrated the feasibility of earthquake early warning, from event detection to producing USGS issued ShakeAlerts ® and will continue to undergo testing and will improve over time. In particular, robust and reliable alert delivery pathways for automated actions are currently being developed and implemented by private industry partners for use in California, Oregon, and Washington.

Earthquake Early Warning Background

The objective of an earthquake early warning system is to rapidly detect the initiation of an earthquake, estimate the level of ground shaking intensity to be expected, and issue a warning before significant ground shaking starts. A network of seismic sensors detects the first energy to radiate from an earthquake, the P-wave energy, and the location and the magnitude of the earthquake is rapidly determined. Then, the anticipated ground shaking across the region to be affected is estimated. The system can provide warning before the S-wave arrives, which brings the strong shaking that usually causes most of the damage. Warnings will be distributed to local and state public emergency response officials, critical infrastructure, private businesses, and the public. EEW systems have been successfully implemented in Japan, Taiwan, Mexico, and other nations with varying degrees of sophistication and coverage.

Earthquake early warning can provide enough time to:

Instruct students and employees to take a protective action such as Drop, Cover, and Hold On
Initiate mass notification procedures
Open fire-house doors and notify local first responders
Slow and stop trains and taxiing planes
Install measures to prevent/limit additional cars from going on bridges, entering tunnels, and being on freeway overpasses before the shaking starts
Move people away from dangerous machines or chemicals in work environments
Shut down gas lines, water treatment plants, or nuclear reactors
Automatically shut down and isolate industrial systems

However, earthquake warning notifications must be transmitted without requiring human review and response action must be automated, as the total warning times are short depending on geographic distance and varying soil densities from the epicenter.

_____________________________________________________________________________________

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

The Department of Earth, Atmospheric and Planetary Sciences (EAPS) is the place at MIT where the turbulent oceans and atmosphere, the inaccessible depths of the inner Earth, distant planets, and the origins of life all come together under one intellectual roof.

USPS “Forever” postage stamps celebrating Innovation at MIT.

The Massachusetts Institute of Technology (US) is a private land-grant research university in Cambridge, Massachusetts. The institute has an urban campus that extends more than a mile (1.6 km) alongside the Charles River. The institute also encompasses a number of major off-campus facilities such as the MIT Lincoln Laboratory (US), the MIT Bates Research and Engineering Center (US), and the Haystack Observatory (US), as well as affiliated laboratories such as the Broad Institute of MIT and Harvard(US) and Whitehead Institute (US).

Massachusettes Institute of Technology-Haystack Observatory(US) Westford, Massachusetts, USA, Altitude 131 m (430 ft).

Founded in 1861 in response to the increasing industrialization of the United States, Massachusetts Institute of Technology (US) adopted a European polytechnic university model and stressed laboratory instruction in applied science and engineering. It has since played a key role in the development of many aspects of modern science, engineering, mathematics, and technology, and is widely known for its innovation and academic strength. It is frequently regarded as one of the most prestigious universities in the world.

As of December 2020, 97 Nobel laureates, 26 Turing Award winners, and 8 Fields Medalists have been affiliated with MIT as alumni, faculty members, or researchers. In addition, 58 National Medal of Science recipients, 29 National Medals of Technology and Innovation recipients, 50 MacArthur Fellows, 80 Marshall Scholars, 3 Mitchell Scholars, 22 Schwarzman Scholars, 41 astronauts, and 16 Chief Scientists of the U.S. Air Force have been affiliated with The Massachusetts Institute of Technology (US) . The university also has a strong entrepreneurial culture and MIT alumni have founded or co-founded many notable companies. Massachusetts Institute of Technology (US) is a member of the Association of American Universities (AAU).

Foundation and vision

In 1859, a proposal was submitted to the Massachusetts General Court to use newly filled lands in Back Bay, Boston for a “Conservatory of Art and Science”, but the proposal failed. A charter for the incorporation of the Massachusetts Institute of Technology, proposed by William Barton Rogers, was signed by John Albion Andrew, the governor of Massachusetts, on April 10, 1861.

Rogers, a professor from the University of Virginia (US), wanted to establish an institution to address rapid scientific and technological advances. He did not wish to found a professional school, but a combination with elements of both professional and liberal education, proposing that:

“The true and only practicable object of a polytechnic school is, as I conceive, the teaching, not of the minute details and manipulations of the arts, which can be done only in the workshop, but the inculcation of those scientific principles which form the basis and explanation of them, and along with this, a full and methodical review of all their leading processes and operations in connection with physical laws.”

The Rogers Plan reflected the German research university model, emphasizing an independent faculty engaged in research, as well as instruction oriented around seminars and laboratories.

Early developments

Two days after Massachusetts Institute of Technology (US) was chartered, the first battle of the Civil War broke out. After a long delay through the war years, MIT’s first classes were held in the Mercantile Building in Boston in 1865. The new institute was founded as part of the Morrill Land-Grant Colleges Act to fund institutions “to promote the liberal and practical education of the industrial classes” and was a land-grant school. In 1863 under the same act, the Commonwealth of Massachusetts founded the Massachusetts Agricultural College, which developed as the University of Massachusetts Amherst (US)). In 1866, the proceeds from land sales went toward new buildings in the Back Bay.

Massachusetts Institute of Technology (US) was informally called “Boston Tech”. The institute adopted the European polytechnic university model and emphasized laboratory instruction from an early date. Despite chronic financial problems, the institute saw growth in the last two decades of the 19th century under President Francis Amasa Walker. Programs in electrical, chemical, marine, and sanitary engineering were introduced, new buildings were built, and the size of the student body increased to more than one thousand.

The curriculum drifted to a vocational emphasis, with less focus on theoretical science. The fledgling school still suffered from chronic financial shortages which diverted the attention of the MIT leadership. During these “Boston Tech” years, Massachusetts Institute of Technology (US) faculty and alumni rebuffed Harvard University (US) president (and former MIT faculty) Charles W. Eliot’s repeated attempts to merge MIT with Harvard College’s Lawrence Scientific School. There would be at least six attempts to absorb MIT into Harvard. In its cramped Back Bay location, MIT could not afford to expand its overcrowded facilities, driving a desperate search for a new campus and funding. Eventually, the MIT Corporation approved a formal agreement to merge with Harvard, over the vehement objections of MIT faculty, students, and alumni. However, a 1917 decision by the Massachusetts Supreme Judicial Court effectively put an end to the merger scheme.

In 1916, the Massachusetts Institute of Technology (US) administration and the MIT charter crossed the Charles River on the ceremonial barge Bucentaur built for the occasion, to signify MIT’s move to a spacious new campus largely consisting of filled land on a one-mile-long (1.6 km) tract along the Cambridge side of the Charles River. The neoclassical “New Technology” campus was designed by William W. Bosworth and had been funded largely by anonymous donations from a mysterious “Mr. Smith”, starting in 1912. In January 1920, the donor was revealed to be the industrialist George Eastman of Rochester, New York, who had invented methods of film production and processing, and founded Eastman Kodak. Between 1912 and 1920, Eastman donated $20 million ($236.6 million in 2015 dollars) in cash and Kodak stock to MIT.

Curricular reforms

In the 1930s, President Karl Taylor Compton and Vice-President (effectively Provost) Vannevar Bush emphasized the importance of pure sciences like physics and chemistry and reduced the vocational practice required in shops and drafting studios. The Compton reforms “renewed confidence in the ability of the Institute to develop leadership in science as well as in engineering”. Unlike Ivy League schools, Massachusetts Institute of Technology (US) catered more to middle-class families, and depended more on tuition than on endowments or grants for its funding. The school was elected to the Association of American Universities (US)in 1934.

Still, as late as 1949, the Lewis Committee lamented in its report on the state of education at Massachusetts Institute of Technology (US) that “the Institute is widely conceived as basically a vocational school”, a “partly unjustified” perception the committee sought to change. The report comprehensively reviewed the undergraduate curriculum, recommended offering a broader education, and warned against letting engineering and government-sponsored research detract from the sciences and humanities. The School of Humanities, Arts, and Social Sciences and the MIT Sloan School of Management were formed in 1950 to compete with the powerful Schools of Science and Engineering. Previously marginalized faculties in the areas of economics, management, political science, and linguistics emerged into cohesive and assertive departments by attracting respected professors and launching competitive graduate programs. The School of Humanities, Arts, and Social Sciences continued to develop under the successive terms of the more humanistically oriented presidents Howard W. Johnson and Jerome Wiesner between 1966 and 1980.

Massachusetts Institute of Technology (US)‘s involvement in military science surged during World War II. In 1941, Vannevar Bush was appointed head of the federal Office of Scientific Research and Development and directed funding to only a select group of universities, including MIT. Engineers and scientists from across the country gathered at Massachusetts Institute of Technology (US)’s Radiation Laboratory, established in 1940 to assist the British military in developing microwave radar. The work done there significantly affected both the war and subsequent research in the area. Other defense projects included gyroscope-based and other complex control systems for gunsight, bombsight, and inertial navigation under Charles Stark Draper’s Instrumentation Laboratory; the development of a digital computer for flight simulations under Project Whirlwind; and high-speed and high-altitude photography under Harold Edgerton. By the end of the war, Massachusetts Institute of Technology (US) became the nation’s largest wartime R&D contractor (attracting some criticism of Bush), employing nearly 4000 in the Radiation Laboratory alone and receiving in excess of $100 million ($1.2 billion in 2015 dollars) before 1946. Work on defense projects continued even after then. Post-war government-sponsored research at MIT included SAGE and guidance systems for ballistic missiles and Project Apollo.

These activities affected Massachusetts Institute of Technology (US) profoundly. A 1949 report noted the lack of “any great slackening in the pace of life at the Institute” to match the return to peacetime, remembering the “academic tranquility of the prewar years”, though acknowledging the significant contributions of military research to the increased emphasis on graduate education and rapid growth of personnel and facilities. The faculty doubled and the graduate student body quintupled during the terms of Karl Taylor Compton, president of Massachusetts Institute of Technology (US) between 1930 and 1948; James Rhyne Killian, president from 1948 to 1957; and Julius Adams Stratton, chancellor from 1952 to 1957, whose institution-building strategies shaped the expanding university. By the 1950s, Massachusetts Institute of Technology (US) no longer simply benefited the industries with which it had worked for three decades, and it had developed closer working relationships with new patrons, philanthropic foundations and the federal government.

In late 1960s and early 1970s, student and faculty activists protested against the Vietnam War and Massachusetts Institute of Technology (US)’s defense research. In this period Massachusetts Institute of Technology (US)’s various departments were researching helicopters, smart bombs and counterinsurgency techniques for the war in Vietnam as well as guidance systems for nuclear missiles. The Union of Concerned Scientists was founded on March 4, 1969 during a meeting of faculty members and students seeking to shift the emphasis on military research toward environmental and social problems. Massachusetts Institute of Technology (US) ultimately divested itself from the Instrumentation Laboratory and moved all classified research off-campus to the MIT (US) Lincoln Laboratory facility in 1973 in response to the protests. The student body, faculty, and administration remained comparatively unpolarized during what was a tumultuous time for many other universities. Johnson was seen to be highly successful in leading his institution to “greater strength and unity” after these times of turmoil. However six Massachusetts Institute of Technology (US) students were sentenced to prison terms at this time and some former student leaders, such as Michael Albert and George Katsiaficas, are still indignant about MIT’s role in military research and its suppression of these protests. (Richard Leacock’s film, November Actions, records some of these tumultuous events.)

In the 1980s, there was more controversy at Massachusetts Institute of Technology (US) over its involvement in SDI (space weaponry) and CBW (chemical and biological warfare) research. More recently, Massachusetts Institute of Technology (US)’s research for the military has included work on robots, drones and ‘battle suits’.

Recent history

Massachusetts Institute of Technology (US) has kept pace with and helped to advance the digital age. In addition to developing the predecessors to modern computing and networking technologies, students, staff, and faculty members at Project MAC, the Artificial Intelligence Laboratory, and the Tech Model Railroad Club wrote some of the earliest interactive computer video games like Spacewar! and created much of modern hacker slang and culture. Several major computer-related organizations have originated at MIT since the 1980s: Richard Stallman’s GNU Project and the subsequent Free Software Foundation were founded in the mid-1980s at the AI Lab; the MIT Media Lab was founded in 1985 by Nicholas Negroponte and Jerome Wiesner to promote research into novel uses of computer technology; the World Wide Web Consortium standards organization was founded at the Laboratory for Computer Science in 1994 by Tim Berners-Lee; the MIT OpenCourseWare project has made course materials for over 2,000 Massachusetts Institute of Technology (US) classes available online free of charge since 2002; and the One Laptop per Child initiative to expand computer education and connectivity to children worldwide was launched in 2005.

Massachusetts Institute of Technology (US) was named a sea-grant college in 1976 to support its programs in oceanography and marine sciences and was named a space-grant college in 1989 to support its aeronautics and astronautics programs. Despite diminishing government financial support over the past quarter century, MIT launched several successful development campaigns to significantly expand the campus: new dormitories and athletics buildings on west campus; the Tang Center for Management Education; several buildings in the northeast corner of campus supporting research into biology, brain and cognitive sciences, genomics, biotechnology, and cancer research; and a number of new “backlot” buildings on Vassar Street including the Stata Center. Construction on campus in the 2000s included expansions of the Media Lab, the Sloan School’s eastern campus, and graduate residences in the northwest. In 2006, President Hockfield launched the MIT Energy Research Council to investigate the interdisciplinary challenges posed by increasing global energy consumption.

In 2001, inspired by the open source and open access movements, Massachusetts Institute of Technology (US) launched OpenCourseWare to make the lecture notes, problem sets, syllabi, exams, and lectures from the great majority of its courses available online for no charge, though without any formal accreditation for coursework completed. While the cost of supporting and hosting the project is high, OCW expanded in 2005 to include other universities as a part of the OpenCourseWare Consortium, which currently includes more than 250 academic institutions with content available in at least six languages. In 2011, Massachusetts Institute of Technology (US) announced it would offer formal certification (but not credits or degrees) to online participants completing coursework in its “MITx” program, for a modest fee. The “edX” online platform supporting MITx was initially developed in partnership with Harvard and its analogous “Harvardx” initiative. The courseware platform is open source, and other universities have already joined and added their own course content. In March 2009 the Massachusetts Institute of Technology (US) faculty adopted an open-access policy to make its scholarship publicly accessible online.

Massachusetts Institute of Technology (US) has its own police force. Three days after the Boston Marathon bombing of April 2013, MIT Police patrol officer Sean Collier was fatally shot by the suspects Dzhokhar and Tamerlan Tsarnaev, setting off a violent manhunt that shut down the campus and much of the Boston metropolitan area for a day. One week later, Collier’s memorial service was attended by more than 10,000 people, in a ceremony hosted by the Massachusetts Institute of Technology (US) community with thousands of police officers from the New England region and Canada. On November 25, 2013, Massachusetts Institute of Technology (US) announced the creation of the Collier Medal, to be awarded annually to “an individual or group that embodies the character and qualities that Officer Collier exhibited as a member of the Massachusetts Institute of Technology (US) community and in all aspects of his life”. The announcement further stated that “Future recipients of the award will include those whose contributions exceed the boundaries of their profession, those who have contributed to building bridges across the community, and those who consistently and selflessly perform acts of kindness”.

In September 2017, the school announced the creation of an artificial intelligence research lab called the MIT-IBM Watson AI Lab. IBM will spend $240 million over the next decade, and the lab will be staffed by MIT and IBM scientists. In October 2018 MIT announced that it would open a new Schwarzman College of Computing dedicated to the study of artificial intelligence, named after lead donor and The Blackstone Group CEO Stephen Schwarzman. The focus of the new college is to study not just AI, but interdisciplinary AI education, and how AI can be used in fields as diverse as history and biology. The cost of buildings and new faculty for the new college is expected to be $1 billion upon completion.

The Caltech/MIT Advanced aLIGO (US) was designed and constructed by a team of scientists from California Institute of Technology (US), Massachusetts Institute of Technology (US), and industrial contractors, and funded by the National Science Foundation (US) .

Caltech /MIT Advanced aLigo

It was designed to open the field of gravitational-wave astronomy through the detection of gravitational waves predicted by general relativity. Gravitational waves were detected for the first time by the LIGO detector in 2015. For contributions to the LIGO detector and the observation of gravitational waves, two Caltech physicists, Kip Thorne and Barry Barish, and Massachusetts Institute of Technology (US) physicist Rainer Weiss won the Nobel Prize in physics in 2017. Weiss, who is also an Massachusetts Institute of Technology (US) graduate, designed the laser interferometric technique, which served as the essential blueprint for the LIGO.

The mission of Massachusetts Institute of Technology (US) is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of The Massachusetts Institute of Technology community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

From Washington University in St.Louis (US): “Tug of sun and moon could be driving plate motions on ‘imbalanced’ Earth”

From Washington University in St. Louis (US)

January 21, 2022

Talia Ogliore
talia.ogliore@wustl.edu

Credit: Shutterstock.

A study led by geophysicist Anne M. Hofmeister in Arts & Sciences at Washington University in St. Louis proposes that imbalanced forces and torques in the Earth-moon-sun system drive circulation of the whole mantle.

The new analysis provides an alternative to the hypothesis that the movement of tectonic plates is related to convection currents in the Earth’s mantle. Convection involves buoyant rise of heated fluids, which Hofmeister and her colleagues argue does not apply to solid rocks. They argue that force, not heat, moves large objects. The new research is published in a special paper of The Geological Society of America, as part of a forthcoming collection assembled in honor of geologist Warren B. Hamilton.

Earth’s internal workings are popularly modeled as dissipating heat generated by internal radioactivity and from leftover energy created during collisions when our planet formed. But even mantle convection proponents recognize that that amount of internal heat-energy is insufficient to drive large-scale tectonics. And there are other problems with using convection to explain observed plate motions.

Instead, Earth’s plates might be shifting because the sun exerts such a strong gravitational pull on the moon that it has caused the moon’s orbit around Earth to become elongated.

Over time, the position of the barycenter — the center of mass between the orbiting bodies of the Earth and the moon — has moved closer to Earth’s surface and now oscillates 600 km per month relative to the geocenter, Hofmeister said. This sets up internal stresses, as the Earth continues to spin.

“Because the oscillating barycenter lies ~4600 km from the geocenter, Earth’s tangential orbital acceleration and solar pull are imbalanced except at the barycenter,” Hofmeister said. “The planet’s warm, thick and strong interior layers can withstand these stresses, but its thin, cold, brittle lithosphere responds by fracturing.”

Daily spin flattens the Earth from a perfect spherical shape which contributes to the brittle failure of the lithosphere. These two independent stresses create the mosaic of plates observed in the outer shell, the authors suggest. The variety of plate motions comes from the changes in size and direction of the imbalanced gravitational forces with time.

But how to test this alternative? Hofmeister suggested: “One test would be a detailed examination of the tectonics of Pluto, which is too small and cold to convect, but has a giant moon and a surprisingly young surface.”

The study includes a comparison of rocky planets that shows that the presence and longevity of volcanism and tectonism depend on the particular combination of moon size, moon orbital orientation, proximity to the sun and rates of body spin and cooling.

Earth is the only rocky planet with all the factors needed for plate tectonics, Hofmeister noted.

“Our uniquely large moon and particular distance from the sun are essential,” she said.

See the full article here .

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Please help promote STEM in your local schools.

Stem Education Coalition

Washington University in St. Louis (US) is a private research university in Greater St. Louis with its main campus (Danforth) mostly in unincorporated St. Louis County, Missouri, and Clayton, Missouri. It also has a West Campus in Clayton, North Campus in the West End neighborhood of St. Louis, Missouri, and Medical Campus in the Central West End neighborhood of St. Louis, Missouri.

Founded in 1853 and named after George Washington, the university has students and faculty from all 50 U.S. states and more than 120 countries. Washington University is composed of seven graduate and undergraduate schools that encompass a broad range of academic fields. To prevent confusion over its location, the Board of Trustees added the phrase “in St. Louis” in 1976. Washington University is a member of the Association of American Universities (US) and is classified among “R1: Doctoral Universities – Very high research activity”.

As of 2020, 25 Nobel laureates in economics, physiology and medicine, chemistry, and physics have been affiliated with Washington University, ten having done the major part of their pioneering research at the university. In 2019, Clarivate Analytics ranked Washington University 7th in the world for most cited researchers. The university also received the 4th highest amount of National Institutes of Health (US) medical research grants among medical schools in 2019.

Washington University was conceived by 17 St. Louis business, political, and religious leaders concerned by the lack of institutions of higher learning in the Midwest. Missouri State Senator Wayman Crow and Unitarian minister William Greenleaf Eliot, grandfather of the poet T.S. Eliot, led the effort.

The university’s first chancellor was Joseph Gibson Hoyt. Crow secured the university charter from the Missouri General Assembly in 1853, and Eliot was named President of the Board of Trustees. Early on, Eliot solicited support from members of the local business community, including John O’Fallon, but Eliot failed to secure a permanent endowment. Washington University is unusual among major American universities in not having had a prior financial endowment. The institution had no backing of a religious organization, single wealthy patron, or earmarked government support.

During the three years following its inception, the university bore three different names. The board first approved “Eliot Seminary,” but William Eliot was uncomfortable with naming a university after himself and objected to the establishment of a seminary, which would implicitly be charged with teaching a religious faith. He favored a nonsectarian university. In 1854, the Board of Trustees changed the name to “Washington Institute” in honor of George Washington, and because the charter was coincidentally passed on Washington’s birthday, February 22. Naming the university after the nation’s first president, only seven years before the American Civil War and during a time of bitter national division, was no coincidence. During this time of conflict, Americans universally admired George Washington as the father of the United States and a symbol of national unity. The Board of Trustees believed that the university should be a force of unity in a strongly divided Missouri. In 1856, the university amended its name to “Washington University.” The university amended its name once more in 1976, when the Board of Trustees voted to add the suffix “in St. Louis” to distinguish the university from the over two dozen other universities bearing Washington’s name.

Although chartered as a university, for many years Washington University functioned primarily as a night school located on 17th Street and Washington Avenue in the heart of downtown St. Louis. Owing to limited financial resources, Washington University initially used public buildings. Classes began on October 22, 1854, at the Benton School building. At first the university paid for the evening classes, but as their popularity grew, their funding was transferred to the St. Louis Public Schools. Eventually the board secured funds for the construction of Academic Hall and a half dozen other buildings. Later the university divided into three departments: the Manual Training School, Smith Academy, and the Mary Institute.

In 1867, the university opened the first private nonsectarian law school west of the Mississippi River. By 1882, Washington University had expanded to numerous departments, which were housed in various buildings across St. Louis. Medical classes were first held at Washington University in 1891 after the St. Louis Medical College decided to affiliate with the university, establishing the School of Medicine. During the 1890s, Robert Sommers Brookings, the president of the Board of Trustees, undertook the tasks of reorganizing the university’s finances, putting them onto a sound foundation, and buying land for a new campus.

In 1896, Holmes Smith, professor of Drawing and History of Art, designed what would become the basis for the modern day university seal. The seal is made up of elements from the Washington family coat of arms, and the symbol of Louis IX, whom the city is named after.

Washington University spent its first half century in downtown St. Louis bounded by Washington Ave., Lucas Place, and Locust Street. By the 1890s, owing to the dramatic expansion of the Medical School and a new benefactor in Robert Brookings, the university began to move west. The university board of directors began a process to find suitable ground and hired the landscape architecture firm Olmsted, Olmsted & Eliot of Boston. A committee of Robert S. Brookings, Henry Ware Eliot, and William Huse found a site of 103 acres (41.7 ha) just beyond Forest Park, located west of the city limits in St. Louis County. The elevation of the land was thought to resemble the Acropolis and inspired the nickname of “Hilltop” campus, renamed the Danforth campus in 2006 to honor former chancellor William H. Danforth.

In 1899, the university opened a national design contest for the new campus. The renowned Philadelphia firm Cope & Stewardson (same architects who designed a large part of The University of Pennsylvania (US) and Princeton University (US)) won unanimously with its plan for a row of Collegiate Gothic quadrangles inspired by The University of Oxford (UK) and The University of Cambridge (UK). The cornerstone of the first building, Busch Hall, was laid on October 20, 1900. The construction of Brookings Hall, Ridgley, and Cupples began shortly thereafter. The school delayed occupying these buildings until 1905 to accommodate the 1904 World’s Fair and Olympics. The delay allowed the university to construct ten buildings instead of the seven originally planned. This original cluster of buildings set a precedent for the development of the Danforth Campus; Cope & Stewardson’s original plan and its choice of building materials have, with few exceptions, guided the construction and expansion of the Danforth Campus to the present day.

By 1915, construction of a new medical complex was completed on Kingshighway in what is now St. Louis’s Central West End. Three years later, Washington University admitted its first women medical students.

In 1922, a young physics professor, Arthur Holly Compton, conducted a series of experiments in the basement of Eads Hall that demonstrated the “particle” concept of electromagnetic radiation. Compton’s discovery, known as the “Compton Effect,” earned him the Nobel Prize in physics in 1927.

During World War II, as part of the Manhattan Project, a cyclotron at Washington University was used to produce small quantities of the newly discovered element plutonium via neutron bombardment of uranium nitrate hexahydrate. The plutonium produced there in 1942 was shipped to the Metallurgical Laboratory Compton had established at The University of Chicago (US) where Glenn Seaborg’s team used it for extraction, purification, and characterization studies of the exotic substance.

After working for many years at the University of Chicago, Arthur Holly Compton returned to St. Louis in 1946 to serve as Washington University’s ninth chancellor. Compton reestablished the Washington University football team, making the declaration that athletics were to be henceforth played on a “strictly amateur” basis with no athletic scholarships. Under Compton’s leadership, enrollment at the university grew dramatically, fueled primarily by World War II veterans’ use of their GI Bill benefits.

In 1947, Gerty Cori, a professor at the School of Medicine, became the first woman to win a Nobel Prize in Physiology or Medicine.

Cray Cori II supercomputer at National Energy Research Scientific Computing Center(US) at DOE’s Lawrence Berkeley National Laboratory(US), named after Gerty Cori, the first American woman to win a Nobel Prize in science.

Professors Carl and Gerty Cori became Washington University’s fifth and sixth Nobel laureates for their discovery of how glycogen is broken down and resynthesized in the body.

The process of desegregation at Washington University began in 1947 with the School of Medicine and the School of Social Work. During the mid and late 1940s, the university was the target of critical editorials in the local African American press, letter-writing campaigns by churches and the local Urban League, and legal briefs by the NAACP intended to strip its tax-exempt status. In spring 1949, a Washington University student group, the Student Committee for the Admission of Negroes (SCAN), began campaigning for full racial integration. In May 1952, the Board of Trustees passed a resolution desegregating the school’s undergraduate divisions.

During the latter half of the 20th century, Washington University transitioned from a strong regional university to a national research institution. In 1957, planning began for the construction of the “South 40,” a complex of modern residential halls which primarily house Freshmen and some Sophomore students. With the additional on-campus housing, Washington University, which had been predominantly a “streetcar college” of commuter students, began to attract a more national pool of applicants. By 1964, over two-thirds of incoming students came from outside the St. Louis area.

In 1971, the Board of Trustees appointed Chancellor William Henry Danforth, who guided the university through the social and financial crises of the 1970s and strengthened the university’s often strained relationship with the St. Louis community. During his 24-year chancellorship, Danforth significantly improved the School of Medicine, established 70 new faculty chairs, secured a $1.72 billion endowment, and tripled the amount of student scholarships.

In 1995, Mark S. Wrighton, former Provost at The Massachusetts Institute of Technology (US), was elected the university’s 14th chancellor. During Chancellor Wrighton’s tenure undergraduate applications to Washington University more than doubled. Since 1995, the university has added more than 190 endowed professorships, revamped its Arts & Sciences curriculum, and completed more than 30 new buildings.

The growth of Washington University’s reputation coincided with a series of record-breaking fund-raising efforts during the last three decades. From 1983 to 1987, the Alliance for Washington University campaign raised $630.5 million, which was then the most successful fund-raising effort in national history. From 1998 to 2004, the Campaign for Washington University raised $1.55 billion, which was applied to additional scholarships, professorships, and research initiatives.

In 2002, Washington University co-founded the Cortex Innovation Community in St. Louis’s Midtown neighborhood. Cortex is the largest innovation hub in the midwest, home to offices of Square, Microsoft, Aon, Boeing, and Centene. The innovation hub has generated more than 3,800 tech jobs in 14 years.

In 2005, Washington University founded the McDonnell International Scholars Academy, an international network of premier research universities, with an initial endowment gift of $10 million from John F. McDonnell. The academy, which selects scholars from 35 partner universities around the world, was created with the intent to develop a cohort of future leaders, strengthen ties with top foreign universities, and promote global awareness and social responsibility.

In 2019, Washington University unveiled a $360 million campus transformation project known as the East End Transformation. The transformation project, built on the original 1895 campus plan by Olmsted, Olmsted & Eliot, encompassed 18 acres of the Danforth Campus, adding five new buildings, expanding the university’s Mildred Lane Kemper Art Museum, relocating hundreds of surface parking spaces underground, and creating an expansive new park.

In June 2019, Andrew D. Martin, former dean of the College of Literature, Science, and the Arts at The University of Michigan (US), was elected the university’s 15th chancellor. On the day of his inauguration, Chancellor Martin announced the WashU Pledge, a financial aid program allowing full-time Missouri and southern Illinois students who are Pell Grant-eligible or from families with annual incomes of $75,000 or less to attend the university cost-free.

Washington University’s undergraduate program is ranked 14th in the nation in the 2022 U.S. News & World Report National Universities ranking, and 11th by The Wall Street Journal in their 2018 rankings. The university is ranked 22nd in the world for 2019 by The Academic Ranking of World Universities. Undergraduate admission to Washington University is characterized by The Carnegie Foundation and U.S. News & World Report as “most selective”. The Princeton Review, in its 2020 edition, gave the university an admissions selectivity rating of 99 out of 99. The acceptance rate for the class of 2024 (those entering in the fall of 2020) was 12.8%, with students selected from more than 27,900 applications. Of students admitted, 92 percent were in the top 10 percent of their class.

The Princeton Review ranked Washington University 1st for Best College Dorms and 3rd for Best College Food, Best-Run Colleges, and Best Financial Aid in its 2020 edition. Niche listed the university as the best college for architecture and the second-best college campus and college dorms in the United States in 2020. The Washington University School of Medicine was ranked 6th for research by U.S. News & World Report in 2020 and has been listed among the top ten medical schools since the rankings were first published in 1987. Additionally, U.S. News & World Report ranked the university’s genetics and physical therapy as tied for first place. QS World University Rankings ranked Washington University 6th in the world for anatomy and physiology in 2020. In January 2020, Olin Business School was named The Poets & Quants MBA Program of 2019. Washington University has also been recognized as the 12th best university employer in the country by Forbes.

Washington University was named one of the “25 New Ivies” by Newsweek in 2006 and has also been called a “Hidden Ivy”.

A 2014 study ranked Washington University #1 in the country for income inequality, when measured as the ratio of number of students from the top 1% of the income scale to number of students from the bottom 60% of the income scale. About 22% of Washington University’s students came from the top 1%, while only about 6% came from the bottom 60%. In 2015, university administration announced plans to increase the number of Pell-eligible recipients on campus from 6% to 13% by 2020, and in 2019 15% of the university’s student body was eligible for Pell Grants. In October 2019, then newly inaugurated Chancellor Andrew D. Martin announced the WashU Pledge, a financial aid program that provides a free undergraduate education to all full-time Missouri and Southern Illinois students who are Pell Grant-eligible or from families with annual incomes of $75,000 or less. The university’s refusal to divest from the fossil fuel industry has drawn controversy in recent years.

Research

Virtually all faculty members at Washington University engage in academic research, offering opportunities for both undergraduate and graduate students across the university’s seven schools. Known for its interdisciplinary and departmental collaboration, many of Washington University’s research centers and institutes are collaborative efforts between many areas on campus. More than 60% of undergraduates are involved in faculty research across all areas; it is an institutional priority for undergraduates to be allowed to participate in advanced research. According to the Center for Measuring University Performance, it is considered to be one of the top 10 private research universities in the nation. A dedicated Office of Undergraduate Research is located on the Danforth Campus and serves as a resource to post research opportunities, advise students in finding appropriate positions matching their interests, publish undergraduate research journals, and award research grants to make it financially possible to perform research.

According to the National Science Foundation (US), Washington University spent $816 million on research and development in 2018, ranking it 27th in the nation. The university has over 150 National Institutes of Health (US) funded inventions, with many of them licensed to private companies. Governmental agencies and non-profit foundations such as the NIH, Department of Defense (US), National Science Foundation (US), and National Aeronautics Space Agency (US) provide the majority of research grant funding, with Washington University being one of the top recipients in NIH grants from year-to-year. Nearly 80% of NIH grants to institutions in the state of Missouri went to Washington University alone in 2007. Washington University and its Medical School play a large part in the Human Genome Project, where it contributes approximately 25% of the finished sequence. The Genome Sequencing Center has decoded the genome of many animals, plants, and cellular organisms, including the platypus, chimpanzee, cat, and corn.

NASA hosts its Planetary Data System Geosciences Node on the campus of Washington University. Professors, students, and researchers have been heavily involved with many unmanned missions to Mars. Professor Raymond Arvidson has been deputy principal investigator of the Mars Exploration Rover mission and co-investigator of the Phoenix lander robotic arm.

Washington University professor Joseph Lowenstein, with the assistance of several undergraduate students, has been involved in editing, annotating, making a digital archive of the first publication of poet Edmund Spenser’s collective works in 100 years. A large grant from the National Endowment for the Humanities (US) has been given to support this ambitious project centralized at Washington University with support from other colleges in the United States.

In 2019, Folding@Home (US), a distributed computing project for performing molecular dynamics simulations of protein dynamics, was moved to Washington University School of Medicine from Stanford University (US). The project, currently led by Dr. Greg Bowman, uses the idle CPU time of personal computers owned by volunteers to conduct protein folding research. Folding@home’s research is primarily focused on biomedical problems such as Alzheimer’s disease, Cancer, Coronavirus disease 2019, and Ebola virus disease. In April 2020, Folding@home became the world’s first exaFLOP computing system with a peak performance of 1.5 exaflops, making it more than seven times faster than the world’s fastest supercomputer, Summit, and more powerful than the top 100 supercomputers in the world, combined.

ORNL OLCF IBM AC922 SUMMIT supercomputer, was No.1 on the TOP500..

From The University of Utah (US) via phys.org : “Possible chemical leftovers from early Earth sit near the core”

From The University of Utah (US)

via

phys.org

December 30, 2021

Credit: Pixabay/CC0 Public Domain.

Let’s take a journey into the depths of the Earth, down through the crust and mantle nearly to the core. We’ll use seismic waves to show the way, since they echo through the planet following an earthquake and reveal its internal structure like radar waves.

Down near the core, there are zones where seismic waves slow to a crawl. New research from the University of Utah finds that these enigmatic and descriptively-named ultra-low velocity zones are surprisingly layered. Modeling suggests that it’s possible some of these zones are leftovers from the processes that shaped the early Earth—remnants of incomplete mixing like clumps of flour in the bottom of a bowl of batter.

“Of all of the features we know about in the deep mantle, ultra-low velocity zones represent what are probably the most extreme,” says Michael S. Thorne, associate professor in the Department of Geology and Geophysics. “Indeed, these are some of the most extreme features found anywhere in the planet.”

The study is published in Nature Geoscience and is funded by The National Science Foundation (US).

Into the mantle

Let’s review how the interior of the Earth is structured. We live on the crust, a thin layer of solid rock. Between the crust and the iron-nickel core at the center of the planet is the mantle. It’s not an ocean of lava—instead it’s more like solid rock-but hot and with an ability to move that drives plate tectonics at the surface.

How can we have any idea what’s going on in the mantle and the core? Seismic waves. As they ripple through the Earth after an earthquake, scientists on the surface can measure how and when the waves arrive at monitoring stations around the world. From those measurements, they can back-calculate how the waves were reflected and deflected by structures within the Earth, including layers of different densities. That’s how we know where the boundaries are between the crust, mantle and core—and partially how we know what they’re made of.

Ultra-low velocity zones sit at the bottom of the mantle atop the liquid metal outer core. In these areas, seismic waves slow by as much as half, and density goes up by a third.

Scientists initially thought that these zones were areas where the mantle was partially melted, and might be the source of magma for so-called “hot spot” volcanic regions like Iceland.

“But most of the things we call ultra-low velocity zones don’t appear to be located beneath hot spot volcanoes,” Thorne says, “so that cannot be the whole story.”

So Thorne, postdoctoral scholar Surya Pachhai and colleagues from The Australian National University (AU), The Arizona State University (US) and The University of Calgary (CA) set out to explore an alternate hypothesis: that the ultra-low velocity zones may be regions made of different rocks than the rest of the mantle—and that their composition may hearken back to the early Earth.

Perhaps, Thorne says, ultra-low velocity zones could be collections of iron oxide, which we see as rust at the surface but which can behave as a metal in the deep mantle. If that’s the case, pockets of iron oxide just outside the core might influence the Earth’s magnetic field which is generated just below.

“The physical properties of ultra-low velocity zones are linked to their origin,” Pachhai says, “which in turn provides important information about the thermal and chemical status, evolution and dynamics of Earth’s lowermost mantle—an essential part of mantle convection that drives plate tectonics.”

The Tectonic Plates of the world were mapped in 1996, Geological Survey (US).

Reverse-engineering seismic waves

To get a clear picture, the researchers studied ultra-low velocity zones beneath the Coral Sea, between Australia and New Zealand. It’s an ideal location because of an abundance of earthquakes in the area, which provide a high-resolution seismic picture of the core-mantle boundary. The hope was that high-resolution observations could reveal more about how ultra-low velocity zones are put together.

But getting a seismic image of something through nearly 1800 miles of crust and mantle isn’t easy. It’s also not always conclusive—a thick layer of low-velocity material might reflect seismic waves the same way as a thin layer of even lower-velocity material.

So the team used a reverse-engineering approach.

“We can create a model of the Earth that includes ultra-low wave speed reductions,” Pachhai says, “and then run a computer simulation that tells us what the seismic waveforms would look like if that is what the Earth actually looked like. Our next step is to compare those predicted recordings with the recordings that we actually have.”

Over hundreds of thousands of model runs, the method, called “Bayesian inversion,” yields a mathematically robust model of the interior with a good understanding of the uncertainties and trade-offs of different assumptions in the model.

One particular question the researchers wanted to answer is whether there are internal structures, such as layers, within ultra-low velocity zones. The answer, according to the models, is that layers are highly likely. This is a big deal, because it shows the way to understanding how these zones came to be.

“To our knowledge this is the first study using such a Bayesian approach at this level of detail to investigate ultra-low velocity zones,” Pachhai says, “and it is also the first study to demonstrate strong layering within an ultra-low velocity zone.”

Looking back at the origins of the planet

What does it mean that there are likely layers?

More than four billion years ago, while dense iron was sinking to the core of the early Earth and lighter minerals were floating up into the mantle, a planetary object about the size of Mars may have slammed into the infant planet. The collision may have thrown debris into Earth’s orbit that could have later formed the Moon. It also raised the temperature of the Earth significantly—as you might expect from two planets smashing into each other.

“As a result, a large body of molten material, known as a magma ocean, formed,” Pachhai says. The “ocean” would have consisted of rock, gases and crystals suspended in the magma.

The ocean would have sorted itself out as it cooled, with dense materials sinking and layering on to the bottom of the mantle.

Over the following billions of years, as the mantle churned and convected, the dense layer would have been pushed into small patches, showing up as the layered ultra-low velocity zones we see today.

“So the primary and most surprising finding is that the ultra-low velocity zones are not homogenous but contain strong heterogeneities (structural and compositional variations) within them,” Pachhai says. “This finding changes our view on the origin and dynamics of ultra-low velocity zones. We found that this type of ultra-low velocity zone can be explained by chemical heterogeneities created at the very beginning of the Earth’s history and that they are still not well mixed after 4.5 billion years of mantle convection.”

Not the final word

The study provides some evidence of the origins of some ultra-low velocity zones, although there’s also evidence to suggest different origins for others, such as melting of ocean crust that’s sinking back into the mantle. But if at least some ultra-low velocity zones are leftovers from the early Earth, they preserve some of the history of the planet that otherwise has been lost.

“Therefore, our discovery provides a tool to understand the initial thermal and chemical status of Earth’s mantle,” Pachhai says, “and their long-term evolution.”

See the full article here .

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The University of Utah (US) is a public coeducational space-grant research university in Salt Lake City, Utah, United States. As the state’s flagship university, the university offers more than 100 undergraduate majors and more than 92 graduate degree programs. The university is classified in the highest ranking: “R-1: Doctoral Universities – Highest Research Activity” by the Carnegie Classification of Institutions of Higher Education. The Carnegie Classification also considers the university as “selective”, which is its second most selective admissions category. Graduate studies include the S.J. Quinney College of Law and the School of Medicine, Utah’s only medical school. As of Fall 2015, there are 23,909 undergraduate students and 7,764 graduate students, for an enrollment total of 31,673.

The university was established in 1850 as the University of Deseret by the General Assembly of the provisional State of Deseret, making it Utah’s oldest institution of higher education. It received its current name in 1892, four years before Utah attained statehood, and moved to its current location in 1900.

The university ranks among the top 50 U.S. universities by total research expenditures with over $486 million spent in 2014. 22 Rhodes Scholars, three Nobel Prize winners, two Turing Award winners, three MacArthur Fellows, various Pulitzer Prize winners, two astronauts, Gates Cambridge Scholars, and Churchill Scholars have been affiliated with the university as students, researchers, or faculty members in its history. In addition, the university’s Honors College has been reviewed among 50 leading national Honors Colleges in the U.S. The university has also been ranked the 12th most ideologically diverse university in the country.