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  • richardmitnick 8:06 am on January 31, 2018 Permalink | Reply
    Tags: , , Earth Went Strangely Quiet About 2 Billion Years Ago And We Don't Know Why, Geology,   

    From Science Alert: “Earth Went Strangely Quiet About 2 Billion Years Ago And We Don’t Know Why” 

    ScienceAlert

    Science Alert

    31 JAN 2018
    MIKE MCRAE

    1
    (Vadim Sadovski/Shutterstock)

    A new study has added evidence to the hypothesis that our planet experienced a lull in geology between 2.2 and 2.3 billion years ago, when not a lot went on as far as rock-forming processes go.

    The relatively dormant phase in our planet’s history signals a significant change in tectonics, one that is fuelling discussion on exactly how continents form and could possibly provide better details on exactly where we can find new deposits of various mineral resources.

    The era known as the Palaeoproterozoic covers a rather exciting time in Earth’s history, starting 2.5 billion years ago and ending around a billion years later.

    Life was literally a lot simpler then. Days were four hours shorter. Our atmosphere was yet to have a lot of oxygen. There were the first global glaciation events. And the planet’s first supercontinent – a huge chunk of land called Columbia, or Nuna – was in the process of being formed.

    As you might imagine, geologists are keen to understand how this far younger Earth behaved compared to today’s more mature globe.

    It seems as if around 2.45 billion years ago, there was something of a quiet spell beneath the surface, one that lasted around 250 million years.

    Not that everybody is convinced – other interpretations of the research suggest it was business as usual throughout the Palaeoproterozoic [Earth and Planetary Science Letters].

    With the jury still out, more evidence is needed. Which is just what a new study led by researchers from Curtin University has provided.

    A close look at the existing data as well as new rock samples collected from Western Australia, China, Northern Canada and Southern Africa has added weight to what’s described as a tectono-magmatic shutdown.

    “Our research shows a bona fide gap in the Palaeoproterozoic geologic record, with not only a slowing down of the number of volcanoes erupting during this time, but also a slow-down in sedimentation and a noticeable lull in tectonic plate movement,” says Curtin University geoscientist Christopher Spencer.

    Earth’s guts were a lot hotter a few billion years ago. For a while all that churning resulted in a whole lot of volcanic activity.

    Whether that directly led to significant cooling, or if something else happened beneath the crust, nobody is sure.

    But we can now be fairly confident that about 2.3 billion years ago, things went quiet under the lid. Volcanoes were temporarily out of fashion. Plate movements were subdued.

    Earth was taking a break.

    “This ‘dormant’ period lasted around 100 million years and signalled what we believe was a shift from ‘ancient-style’ tectonics to ‘modern-style’ tectonics more akin to those operating in the present day,” says Spencer.

    “It’s almost as if the Earth experienced a mid-life crisis.”

    After a bit of a breather, things ramped up again. Chunks of ancient crust fractured into smaller pieces called cratons, which can today be found deep inside continental plates.

    “Following this dormant period Earth’s geology started to ‘wake-up’ again around 2.2 to 2.0 billion years ago with a ‘flare-up’ of volcanic activity and a shift in the composition of the continental crust,” says Spencer.

    Why did the mantle ‘flare up’ again after a quiet spell? The researchers aren’t sure, but have speculated it might simply come down to a surge of accumulated heat.

    Understanding the geological processes that led from ‘supercratons’ to the first supercontinent could help us understand how many of the mineral resources we rely upon formed and distributed.

    More data is needed to fill in missing details on this geological ‘mid-life crisis’ model, but we can at least be grateful Earth didn’t quit its job and run off with some young moon.

    This research was published in Nature Geoscience.

    See the full article here .

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  • richardmitnick 8:17 am on January 22, 2018 Permalink | Reply
    Tags: , Geology, Mounting Evidence Suggests a Remote Australian Region Was Once Part of North America,   

    From Science Alert: “Mounting Evidence Suggests a Remote Australian Region Was Once Part of North America” 

    ScienceAlert

    Science Alert

    22 JAN 2018
    MICHELLE STARR

    1
    (Janaka Dharmasena/Shutterstock)

    It really is a small world after all.

    Geologists tend to agree that, billions of years ago, the configuration of the continents was very different. How exactly they all fit together and when is a bit more of a puzzle, the pieces of which can be put together by studying rocks and fossils.

    Now researchers have found a series of rocks that show something surprising: part of Australia could have once been connected to part of Canada on the North American continent, around 1.7 billion years ago.

    Actually, the discovery that the two continents were once connected isn’t hugely surprising. Speculation about such a connection has existed since the late 1970s, when a paper proposed a connection dating back to the continent of Rodinia, around 1.13 billion years ago. However, an exact time and location for the connection has remained under debate.

    Found in Georgetown, a small town of just a few hundred people in the north east of Australia, the rocks are unlike other rocks on the Australian continent.

    Instead, they show similarities to ancient rocks found in Canada, in the exposed section of the continental crust called the Canadian Shield.

    This unexpected finding, according to researchers at Curtin University, Monash University and the Geological Survey of Queensland in Australia, reveals something about the composition of the ancient supercontinent Nuna.

    “Our research shows that about 1.7 billion years ago, Georgetown rocks were deposited into a shallow sea when the region was part of North America. Georgetown then broke away from North America and collided with the Mount Isa region of northern Australia around 100 million years later,” said Curtin PhD student and lead researcher Adam Nordsvan.

    “This was a critical part of global continental reorganisation when almost all continents on Earth assembled to form the supercontinent called Nuna.”

    The last time the continents were close to one another was the major supercontinent known as Pangea, which broke apart around 175 million years ago.

    However, before Pangea, the planet went through a number of supercontinent configurations – one of which was Nuna, also called Columbia, which existed from around 2.5 billion to 1.5 billion years ago.

    The team reached its conclusion by examining new sedimentological field data, and new and existing geochronological data from both Georgetown and Mount Isa, another remote town in north east Australia, and comparing it to rocks from Canada.

    According to the research, when Nuna started breaking up, the Georgetown area remained permanently stuck to Australia.

    This, the researchers said in their paper, challenges the current model that suggests the Georgetown region was part of the continent that would become Australia prior to 1.7 billion years ago.

    The research also found new evidence that Georgetown and Mount Isa mountain ranges were formed when the two regions collided.

    “Ongoing research by our team shows that this mountain belt, in contrast to the Himalayas, would not have been very high, suggesting the final continental assembling process that led to the formation of the supercontinent Nuna was not a hard collision like India’s recent collision with Asia,” said co-author Zheng-Xiang Li.

    “This new finding is a key step in understanding how Earth’s first supercontinent Nuna may have formed, a subject still being pursued by our multidisciplinary team here at Curtin University.”

    The research has been published in the journal Geology.

    See the full article here .

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  • richardmitnick 12:56 pm on January 20, 2018 Permalink | Reply
    Tags: , Geology, Geology Makes the Mayon Volcano Visually Spectacular—And Dangerously Explosive, , Strombolian eruptions,   

    From smithsonian.com: “Geology Makes the Mayon Volcano Visually Spectacular—And Dangerously Explosive” 

    smithsonian
    smithsonian.com

    January 19, 2018
    Maya Wei-Haas

    What’s going on inside one of the Philippines’ most active volcanoes?

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    Lava cascades down the slopes of the erupting Mayon volcano in January 2018. Seen from Busay Village in Albay province, 210 miles southeast of Manila, Philippines. (AP Photo/Dan Amaranto)

    Last weekend, the Philippines’ most active—and attractive—volcano, Mount Mayon, roared back to life. The 8,070-foot volcano began releasing spurts of incandescent molten rock and spewing clouds of smoke and ash into the sky, causing over 30,000 local residents to evacuate the region. By the morning of January 18, the gooey streams of lava had traveled almost two miles from the summit.

    Though the images of Mount Mayon are startling, the volcano isn’t truly explosive—yet. The Philippine Institute of Volcanology and Seismology (PHIVolcs), which monitors the numerous volcanoes of the island chain, has set the current warning level at a 3 out of 5, which means that there is ”relatively high unrest.” At this point, explosive eruption is not imminent, says Janine Krippner, a volcanologist and postdoctoral researcher researcher at Concord University. If the trend continues, however, an eruption is possible in the next few weeks.

    Located on the large island of Luzon, Mount Mayon is known for its dramatically sloped edges and picturesque symmetry, which makes it a popular tourist attraction; some climbers even attempt to the venture to its smouldering rim. “It’s gorgeous, isn’t it?” marvels Krippner. But that beauty isn’t entirely innocuous. In fact, Krippner explains, the structure’s symmetrical form is partly due to the frequency of the volcano’s eruptions.

    “Mayon is one of the most active volcanoes—if not the most active volcano—in the Philippines, so it has the chance to keep building its profile up without eroding away,” she says. Since its first recorded eruption in 1616, there have been roughly 58 known events—four in just the last decade—which have ranged from small sputters to full-on disasters. Its most explosive eruption took place in 1814, when columns of ash rose miles high, devastated nearby towns and killed 1200 people.

    Many of these eruptions are strombolian, which means the cone emits a stuttering spray of molten rock that collects around its upper rim. (Strombolian eruptions are among the less-explosive types of blasts, but Mayon is capable of much more violent eruptions as well.) Over time, these volcanic rocks “stack up, and up, and up,” says Krippner, creating extremely steep slope. That’s why, near the top of the volcano, its sides veer at angles up to 40 degrees—roughly twice the angle of the famous Baldwin street in New Zealand, one of the steepest roads in the world.

    So why, exactly, does Mayon have so many fiery fits? It’s all about location.

    The islands of the Philippines are situated along the Ring of Fire, a curving chain of volcanism that hugs the boundary of the Pacific Ocean and contains three-fourths of all the world’s volcanoes. What drives this region of fiery activity are slow-motion collisions between the shifting blocks of Earth’s crust, or tectonic plates, which have been taking place over millions of years. The situation in the Philippines is in particularly complex, explains Ben Andrews, director of Smithsonian’s Global Volcanism Program. “It’s a place where we have a whole bunch of different subduction zones of different ages that are sort of piling together and crashing together,” he says. “It gets pretty hairy.”

    As one plate thrusts beneath another, the rocks begin to melt, fueling the volcanic eruption above. Depending on the composition of the melting rock, the lava can be thin and runny, or thick and viscous. This viscosity paired with the speed at which the magma rises determines the volcano’s explosivity, says Andrews: The thicker and quicker the lava, the more explosive the blast. Mayon produces magma of intermediate composition and viscosity, but it differs from eruption to eruption.

    Think of a volcanic eruption like opening a shaken bottle of soda, says Andrews. If you pop off the cap immediately, you’re in for a spray of sugary carbonated liquid to the face, just like the sudden release of gas and molten rock that builds under a plug of viscous magma. But if you slow down and let a little air out first—like the gases that can escape from liquid-y magma—a violent explosion is less likely.

    News outlets have been reporting on an “imminent explosion,” warning that Mayon will erupt within days. But given its activity so far, it’s not yet clear if, or when, Mayon will erupt. Volcanoes are extremely hard to predict as the magma is constantly changing, says Krippner.

    Since the volcano began belching, small pyroclastic flows—avalanches of hot rocks, ash and gas—have also tumbled down its flanks. Though dangerous, these pyroclastic flows have the potential to be much more devastating. Previously at Mayon, says Krippner, these flows have been clocked in at over 60 meters per second. “They’re extremely fast and they’re extremely hot,” she says. “They destroy pretty much everything in their path.”

    If the eruption continues, one of the biggest dangers is an explosive blast, which could produce a column of volcanic ash miles high. The collapse of this column can send massive, deadly pyroclastic flows racing down the volcano’s flanks. The last time Mayon burst in an explosive eruption was in 2001. With a roar like a jet plane, the volcano shot clouds of ash and molten rock just over six miles into the sky.

    Also of concern is the potential for what are known as lahars, or flows of debris. The volcanic rumblings have been actively producing volcanic ash, a material that’s more like sand than the kind of ash you see when you burn wood or paper, notes Krippner. A strong rain—as is frequent on these tropical islands—is all that’s needed to turn these layers of debris into a slurry and send it careening down the volcano’s slopes, sweeping with it anything that gets in its way. Mayon’s steep sides make it particularly susceptible to these mudflows.

    Residents suffered the full potential for destruction of Mayon’s lahars in November of 2006 when a typhoon swept the region, bringing with it heavy rain that saturated built up material. A massive lahar formed, destroying nearby towns and killing 1,266 people.

    Both Krippner and Andrews stress that local residents are in good hands under PHIVolcs’ careful watch. The researchers have installed a complex network of sensors that monitor Mayon’s every tremble and burp and are using their vast amounts of knowledge garnered from past events to interpret the volcano’s every shiver.

    And as Krippner notes, “it’s still got two more levels to go.” If PHIVoics raises the alert level to a 4 or 5, she says, “that could mean something bigger is coming.”

    See the full article here .

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    Smithsonian magazine and Smithsonian.com place a Smithsonian lens on the world, looking at the topics and subject matters researched, studied and exhibited by the Smithsonian Institution — science, history, art, popular culture and innovation — and chronicling them every day for our diverse readership.

     
  • richardmitnick 10:49 am on January 11, 2018 Permalink | Reply
    Tags: , Carbon cycle, , , Geology, Japan Trench, Radiocarbon dating   

    From ETH Zürich: “Earthquakes as a driver for the deep-ocean carbon cycle” 

    ETH Zurich bloc

    ETH Zürich

    09.01.2018
    Samuel Schlaefli

    An international team led by geologist Michael Strasser has used novel methods to analyse sediment deposits in the Japan Trench in order to gain new insights into the carbon cycle.

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    The research vessel RV Sonne, aboard which the sediment samples in the Japan Trench were taken in 2012. (Image: RF Forschungsschiffahrt Bremen/Germany)

    In a paper recently published in Nature Communications, geologist Michael Strasser presented the initial findings of a month-long research expedition off the coast of Japan. The research initiative had been organised in March 2012 by MARUM – Center for Marine Environmental Sciences. Strasser, who until 2015 was Assistant Professor for Sediment Dynamics at ETH Zürich and is now a Full Professor for Sediment Geology at the University of Innsbruck, took an international team there to study dynamic sediment remobilisation processes triggered by seismic activity.

    At a depth of 7,542 metres below sea level, the team took a core sample from the Japan Trench, an 800-km-long oceanic trench in the northwestern part of the Pacific Ocean. The trench, which is seismically active, was the epicentre of the Tohoku earthquake in 2011, which made headlines when it caused the nuclear meltdown at Fukushima. Such earthquakes wash enormous amounts of organic matter from the shallows down into deeper waters. The resulting sediment layers can thus be used later to glean information about the history of earthquakes and the carbon cycle in the deep ocean.

    New dating methods in the deep ocean

    The current study provided the researchers with a breakthrough. They analysed the carbon-rich sediments using radiocarbon dating. This method – measuring the amount of organic carbon as well as radioactive carbon (14C) in mineralised compounds – has long been a means of determining the age of individual sediment layers. Until now, however, it has not been possible to analyse samples from deeper than 5,000 metres below the surface, because the mineralised compounds dissolve under increased water pressure.

    Strasser and his team therefore had to use new methods for their analysis. One of these was what is known as the online gas radiocarbon method, developed by ETH doctoral student Rui Bao and the Biogeoscience Group at ETH Zürich. This greatly increases efficiency, since it takes just a single core sample to make more than one hundred 14C age measurements directly on the organic matter contained within the sediment.

    In addition, the researchers applied the Ramped PyrOx measurement method (pyrolysis) for the first time in the dating of deep-ocean sediment layers. This was done in cooperation with the Woods Hole Oceanographic Institute (U.S.), which developed the method. The process involves burning organic matter at different temperatures. Because older organic matter contains stronger chemical bonds, it requires higher temperatures to burn. What makes this method novel is that the relative age variation of the individual temperature fractions between two samples very precisely distinguishes the age difference between sediment levels in the deep sea.

    Dating earthquakes to increase forecast accuracy

    Thanks to these two innovative methods, the researchers could determine the relative age of organic matter in individual sediment layers with a high degree of precision. The core sample they tested contained older organic matter in three places, as well as higher rates of carbon export to the deep ocean. These places correspond to three historically documented yet hitherto partially imprecisely dated seismic events in the Japan Trench: the Tohoku earthquake in 2011, an unnamed earthquake in 1454, and the Sanriku earthquake in 869.

    At the moment, Strasser is working on a large-scale geological map of the origin and frequency of sediments in deep-ocean trenches. To do so, he is analysing multiple core samples taken during a follow-up expedition to the Japan Trench in 2016. “The identification and dating of tectonically triggered sediment deposits is also important for future forecasts about the likelihood of earthquakes,” Strasser says. “With our new methods, we can predict the recurrence of earthquakes with much more accuracy.”

    2
    Michael Strasser (right), then assistant professor at ETH Zürich, and expedition head Gerold Wefer, professor at MARUM and Bremen University, make recommendations about the core sample on board the RV Sonne. Source/Copyright: V. Diekamp, MARUM, Bremen University.

    Science team:
    Bao R, Strasser M, McNichol A, Haghipour N, McIntyre C Wefer G, Eglinton T.

    See the full article here .

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    ETH Zurich campus
    ETH Zürich is one of the leading international universities for technology and the natural sciences. It is well known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

    Founded in 1855, ETH Zürich today has more than 18,500 students from over 110 countries, including 4,000 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

    Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zürich, underlining the excellent reputation of the university.

     
  • richardmitnick 5:52 pm on January 3, 2018 Permalink | Reply
    Tags: , , , Geology, Rattlesnake Ridge: a large failure forming in Washington State,   

    From AGU: “Rattlesnake Ridge: a large failure forming in Washington State, USA” 

    AGU bloc

    American Geophysical Union

    3 January 2018
    Dave Petley

    Rattlesnake Ridge is a large hillside located above the I-82 highway to the south of the town of Yakima in Washington State, NW USA. The Google Earth image below shows the location of the site (at 46.524, -120.467), taken in May 2017. The image is looking towards the east – note the large active quarry on the south side of the ridge, and other signs of earlier (and smaller scale) excavation on the slope. Note also the proximity of the slope to I-82.

    1
    Google Earth image of the incipient landslide at Rattlesnake Ridge

    In October 2017 a major fissure started to develop through Rattlesnake Ridge. Over the last three months this apparent tension crack has widened to encompass a volume of about 3 million cubic metres. KXLY has this image providing a perspective of the size of the block that is on the move at Rattlesnake Ridge:-

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    Image of the slope failure at Rattlesnake Ridge, via KXLY

    Whilst the best impression of the feature can be seen in this Youtube video by Steven Mack

    This view of the feature is perhaps the most interesting, showing how the crack extends into the rear face of the quarry.

    4

    The latest reports suggest that the crack is widening at a rate of about 30 cm per week at present. Interestingly KIMA TV reports that the expectation is that the slope will self-stabilise:

    Senior Emergency Planner Horace Ward said they have not determined a cause yet and said it’s just nature. Ward said the ridge is being monitored and they think the slide will stop itself.

    “It could continue to move slowly enough to where it kind of just keeps spilling a little bit of material into the quarry until it creates a toe for itself to stop and stabilize the hillside,” he said.

    The implication of this is that it is a rotational slip. However, the tension crack has quite a complex structure, with some evidence of the development of a graben structure:-

    5
    The trension crack at Rattlesnake Ridge. Still from a Youtube video by Steven Mack

    Combined with the potential for weakening the materials controlling the deformation, this makes forecasting the likely future behaviour of this slope quite challenging, but of course it is the geologists on the ground who are best placed to make a judgement. In the short to medium term high resolution monitoring is the right approach.

    Many thanks to the various people who highlighted this one to me, and provided links. Your help is very much appreciated.

    See the full article here .

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    The purpose of the American Geophysical Union is to promote discovery in Earth and space science for the benefit of humanity.

    To achieve this mission, AGU identified the following core values and behaviors.

    Core Principles

    As an organization, AGU holds a set of guiding core values:

    The scientific method
    The generation and dissemination of scientific knowledge
    Open exchange of ideas and information
    Diversity of backgrounds, scientific ideas and approaches
    Benefit of science for a sustainable future
    International and interdisciplinary cooperation
    Equality and inclusiveness
    An active role in educating and nurturing the next generation of scientists
    An engaged membership
    Unselfish cooperation in research
    Excellence and integrity in everything we do

    When we are at our best as an organization, we embody these values in our behavior as follows:

    We advance Earth and space science by catalyzing and supporting the efforts of individual scientists within and outside the membership.
    As a learned society, we serve the public good by fostering quality in the Earth and space science and by publishing the results of research.
    We welcome all in academic, government, industry and other venues who share our interests in understanding the Earth, planets and their space environment, or who seek to apply this knowledge to solving problems facing society.
    Our scientific mission transcends national boundaries.
    Individual scientists worldwide are equals in all AGU activities.
    Cooperative activities with partner societies of all sizes worldwide enhance the resources of all, increase the visibility of Earth and space science, and serve individual scientists, students, and the public.
    We are our members.
    Dedicated volunteers represent an essential ingredient of every program.
    AGU staff work flexibly and responsively in partnership with volunteers to achieve our goals and objectives.

     
  • richardmitnick 12:23 pm on January 1, 2018 Permalink | Reply
    Tags: , , , Geology, Perovskite, , , Standardizing perovskite aging measurements   

    From EPFL: “Standardizing perovskite aging measurements” 

    EPFL bloc

    École Polytechnique Fédérale de Lausanne

    01.01.18
    Nik Papageorgiou


    EPFL scientists have produced a data-driven proposal for standardizing the measurements of perovskite solar cell stability and degradation. Published in Nature Energy, the work aims to create consensus in the field and overcome one of the major hurdles on the way to commercializing perovskite photovoltaics.

    1
    Perovskite (pronunciation: /pəˈrɒvskaɪt/) is a calcium titanium oxide mineral composed of calcium titanate (CaTiO3). It lends its name to the class of compounds which have the same type of crystal structure as CaTiO3 (XIIA2+VIB4+X2−3), known as the perovskite structure. Many different cations can be embedded in this structure, allowing for the development of diverse engineered materials.
    The mineral was discovered in the Ural Mountains of Russia by Gustav Rose in 1839 and is named after Russian mineralogist Lev Perovski (1792–1856). Perovskite’s notable crystal structure was first described by Victor Goldschmidt in 1926, in his work on tolerance factors. The crystal structure was later published in 1945 from X-ray diffraction data on barium titanate by Helen Dick Megaw. Wikipedia.

    2
    A schematic of a perovskite crystal structure. Clean Energy Institute – University of Washington

    Perovskite solar cells are an alternative to conventional silicon solar cells, and are poised to overtake the market with their high power-conversion efficiencies (over 22% now) and lower capital expenditure and manufacturing costs. But one of the greatest obstacles on this road is stability: to be commercially viable, perovskite solar cells must also be able to maintain their efficiency over time, meaning that they must not degrade significantly over 25 years of service.

    “As a first-order approximation, we are talking about stabilities of several years for the most stable perovskite solar cells,” says Konrad Domanksi, first author on the paper. “We still need an increase of an order of magnitude to reach the stabilities of silicon cells.”

    While research efforts are continuously made to improve perovskite stability, the community is hamstrung by the fact that there are no general standards by which scientists can measure the stability of perovskite solar cells. Consequently, the results coming in from different laboratories and companies cannot be easily compared to each other. And even though dedicated stability measurement standards have been developed for other photovoltaic technologies, they have to be adapted for perovskite solar cells, which show new types of behavior.

    Now, the labs of Michael Grätzel and Anders Hagfeldt at EPFL have carried out a study that proposes to standardize the measurements of perovskite solar cell stability across the entire field. The researchers investigated the effects of different environmental factors on the ageing of perovskite solar cells, looking at the impact of illumination (sunlight-level light), temperature, atmospheric, electrical load, and testing a systematic series of combinations of these.

    “We designed and built a dedicated system to carry out this study,” says Domanski. “It is state-of-the-art for measuring stability of solar cells – we can vary light intensity over samples and control temperature, atmosphere etc. We load the samples, program the experiments, and the data is plotted automatically.”

    The study shows how certain behaviors specific to perovskite solar cells can distort the results of experiments. For example, when the cells are left in the dark, they can recover some of the losses caused by illumination and “start fresh in the morning”. As solar cells naturally undergo day-night cycles, this has important implications on how we define that a solar cell degrades in the first place. It also changes our perception on the metrics used by industry to describe lifetime of solar cells.

    “The work can lay the foundations for standardizing perovskite solar cell ageing,” says Wolfgang Tress, last author on the paper. “The field can use it to develop objective and comparable stability metrics, just like stabilized power is now used as a standard tool for assessing power-conversion efficiency in perovskite solar cells. More importantly, systematically isolating specific degradation factors will help us better understand degradation of perovskite solar cells and improve their lifetimes.”

    “We are not trying to impose standards on the community,” says Domanski. “Rather, being on the forefront on perovskite solar cells and their stability research, we try to lead by example and stimulate the discussion on how these standards should look like. We strongly believe that specific protocols will be adopted by consensus, and that dedicated action groups involving a broad range of researchers will be formed for this purpose.”

    Funding

    Swiss National Science Foundation (FNS)
    King Abdulaziz City for Science and Technology (KACST)

    See the full article here .

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    EPFL is Europe’s most cosmopolitan technical university. It receives students, professors and staff from over 120 nationalities. With both a Swiss and international calling, it is therefore guided by a constant wish to open up; its missions of teaching, research and partnership impact various circles: universities and engineering schools, developing and emerging countries, secondary schools and gymnasiums, industry and economy, political circles and the general public.

     
  • richardmitnick 1:17 pm on December 31, 2017 Permalink | Reply
    Tags: "A Massive Volcano Beneath Europe Is Stirring" 2017, , Campi Flegrei a massive caldera beneath the suburbs of Naples Italy, , Geology, Italy, Mt Vesuvius,   

    From Discover Magazine: “A Massive Volcano Beneath Europe Is Stirring” 2017 

    DiscoverMag

    Discover Magazine

    12
    City of Naples with Mount Vesuvius at sunset. No image credit

    1
    Seen from mountaintop monastery Hermitage dei Camaldoli, the suburban sprawl of greater Naples sits atop a massive volcanic caldera that may be poised to erupt. Posillipo Hill, the dark ridge on the left, is part of the wall of the caldera, which stretches 12 kilometers across. Russ Juskalian.

    Just 10 kilometers from the frenetic pulse of central Naples, in stark contrast to the Italian city’s impressive volcanic-stone churches and effortlessly stylish urbanites, sits a boxy, concrete building. Inside this unremarkable government outpost, accessed through a pair of sliding glass doors, is the Vesuvius Observatory monitoring room, lit by the cool glow of 92 flat-panel screens. On each screen, volcanic activity readings, including those from seismic devices sensitive enough to pick up a passing bus, blink and beep in real time. In the middle of the room is a desk. And in the middle of that desk is a single red phone.

    Twenty-four hours a day, 365 days a year, there are at least two people in the room, ready to pick up the phone and advise the national civilian defense in the event of a volcanic emergency.

    3
    Dozens of monitors at the Vesuvius Observatory outside Naples track earthquakes and other regional volcanic activity. The observatory’s director, Francesca Bianco, points out recent tremors around the facility’s namesake, but the bigger threat to the metropolis may be Campi Flegrei, a massive caldera beneath the suburbs, seen in the upper left monitor. Russ Juskalian.

    But Mount Vesuvius, its iconic cone rising conspicuously on the city’s eastern flank, is not the only concern. A potentially even more destructive volcanic giant is tossing fitfully in its sleep, right on Naples’ doorstep: the caldera of the massive volcano system Campi Flegrei, which translates to the fields of fire.

    3
    Campi Flegrei. Donar Reiskoffer.

    If it erupts, an event some researchers feel is increasingly likely, it could be catastrophic for Italy’s third-largest municipality and the surrounding countryside. Disruptions could stretch far beyond Italy, too, affecting everything from air travel to agriculture, with ash darkening the skies over Europe and the Mediterranean.

    The threat comes from the west, in a pockmarked and mountainous landscape abutting Naples just beyond an elongated ridge thick with lovely villas, called Posillipo Hill. The meaning of the hill’s name, “a respite from worry,” belies the story of its formation. Posillipo is at the edge of a volcano caldera so large that to see its full shape requires an elevated vantage point. To stand within it is to be unable to see it.

    These calderas are born when a volcano system erupts with such force that the resulting crater, instead of merely being flattened, actually slumps downward into the ground afterward. The most powerful eruption believed to be from Campi Flegrei, nearly 40,000 years ago, launched the equivalent of 300 cubic kilometers of ash and pulverized rock skyward. The massive eruption impacted the global climate and may have helped to snuff out the last gasps of the Neanderthals.

    Now there are signs that Campi Flegrei is stirring once more.

    At surface level, the caldera is dotted with steam vents, or fumaroles. One of them, the Solfatara di Pozzuoli, has famously lent its name to fumaroles that emit sulfur — such vents around the world are now known as solfataras. But it was one of Solfatara’s less well-known neighbors, the fumarole Pisciarelli, that attracted attention in 2009. The once-insignificant Pisciarelli started to roar, bubbling mud and spewing steam. It was a hint that something was happening below ground.

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    Volcanologist Giovanni Chiodini (in red) shows a visitor around the edges of the Pisciarelli fumarole, an increasingly active volcanic vent within the Campi Flegrei caldera. Russ Juskalian.

    In 2012, the land within the caldera, which had been rising for nearly a decade, began to rise faster. And in late 2016, a paper in Nature Communications suggested the volcano might be entering a new and potentially much more dangerous phase.

    There’s just one problem: The dynamics of large calderas are at best a mystery, and reconstructing the steps that led to Campi Flegrei’s past eruptions seems as much Delphic interpretation as science. Experts can’t agree on what the volcano is doing, only that the threat it poses is real.

    In the Air

    Campi Flegrei is unique among volcanoes in that it can be reached by subway. In fact, from the trendy beachfront neighborhood of Chiaia in Naples, it’s just two stops to the caldera. “Do you smell that?” says my friend Emanuel Scholz, a German geologist who has joined me in the caldera out of professional curiosity on a mild February morning. It smells like sulfur.

    “This is Campi Flegrei,” says volcanologist Giovanni Chiodini, waiting for us on the subway platform. “Some people think only the Solfatara is the volcano because there is steam coming out. But this is all a volcano.” He moves his arms in a full circle, indicating the entire urban outskirts around us. Then he points down the road toward the Vesuvius Observatory. It’s in the caldera, too, he notes.

    Chiodini, Scholz and I pile into an underpowered van, and we fight our way through winding streets of molasses-slow traffic. Our destination is the Pisciarelli fumarole, on a small hillside just meters behind an artificial soccer field. (The suburban banality of the setting is surreal. I imagine an irate gym teacher with his hand on his forehead as he loses yet another ball to the volcano.)

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    Geologist Emanuel Scholz and an observatory staff member chat beside the Pisciarelli fumarole as it spews gas and boiling mud just a ball’s toss away from a suburban soccer field. Russ Juskalian.

    As we approach the fumarole, white plumes of caustic vapor bite at the insides of my nostrils. I hear the guttural roar of what sounds like a redlining motor. “Some years ago,” says Chiodini, “This was a trickle. Not like today.” Dark, gray mud bubbles violently from the fumarole’s center in fist-sized globules and snakes downhill toward the suburb’s homes. The whole thing has a dank and foreboding air.

    It’s here and at Solfatara that Chiodini believes he’s found the signature of a waking volcano. As the lead author of the 2016 Nature Communications paper, Chiodini documented a change in the molecular makeup of gases spewing from the fumaroles, particularly Solfatara, suggesting that the Campi Flegrei caldera might be approaching the so-called “critical degassing pressure” (CDP), after which an eruption becomes far more likely.

    His argument hinges on the fact that as magma rises through Earth’s crust, it undergoes a process called decompression, during which it releases a variable mix of volatile compounds. At the CDP, this mix switches over almost fully to water vapor. The massive amounts of water-rich gases then heat hydrothermal systems in the surrounding rocks. The result: at least a tenfold increase in heat transported into the rock layers between the magma and the crust’s surface, weakening them.

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    With a slight shift in wind, a cloud of gas from the fumarole engulfs Chiodini. Russ Juskalian.

    Up on a small outcrop above the main vent of the Pisciarelli fumarole, the observatory has two monitoring systems looking for changes in heat and gas composition emerging from the caldera. One, tucked beside solar panels and under a small shelter, is little more than a coffee-filter sized dome. Every two hours, it measures the gases seeping up from the ground. The other is an infrared camera pointing at an even higher outcrop. The heat moving into the rock there, Chiodini explains, might be a good measure of how active the caldera is.

    Similar monitoring stations are scattered across the caldera. And what they’ve recorded is concerning: a 25-year decreasing trend in the ratio of certain gases suggests that decompression is occurring and magma may be rising closer to the surface, while an uptick over the last 15 years in heat transfer matches Chiodini’s model of what CDP will look like.

    The data from the caldera parallels similar trends found before eruptions at smaller volcanoes in Papua New Guinea and the Galapagos. And, according to Chiodini, it suggests that Campi Flegrei’s magma is preparing to let off a dangerous amount of heat. For a while the caldera floor, sitting at ground level, and the rock below it, will act like a plug, holding it all together. But keep adding heat and weakening the rocks, and the plug will eventually fail. Perhaps catastrophically.

    In the Rock

    Giuseppe De Natale, a physicist by training who monitors the volcanoes at the Vesuvius Observatory, had access to the same data as Chiodini. But his conclusions were very different.

    Changes in measures such as heat transfer and gas composition are not necessarily red flags; De Natale and colleagues noted in a Nature Communications paper of their own, published in May, that the majority of episodes of such unrest in a large volcano system do not lead to eruption.

    8
    On the edge of Naples, the Campi Flegrei caldera, a massive volcano, appears to be stirring. One researcher believes the caldera’s magma may be releasing massive amounts of hot gases, which pump heat into an overlying hydrothermal network of water and rock. This added heat weakens the rocks between the magma chamber and ground level — and may make an eruption much more likely. Jay Smith.

    The real worry, De Natale believes, is not decompressing magma but accumulating stress on Earth’s crust. To find signs of impending danger, look to the ground, De Natale tells me: The caldera’s narrative was written into the land’s deformation over millennia.

    The long record comes courtesy of the nearly 2,000-year-old columns amid ruins of an old Roman marketplace still standing near the waterfront of a nearby town called Pozzuoli. Discovered in 1750, the columns puzzled scientists: They’re dotted with boreholes drilled by a marine mollusk known as Lithodomus lithophagus. It took 200 years to solve the riddle. The so-called “stone-eater” mussels had done their work as the columns moved into and out of the water with the fluctuations of the caldera floor’s elevation.

    By dating the holes, scientists reconstructed a remarkably consistent record: The ground in the caldera had been sinking at a steady rate of about 1.7 meters per century. That is, except for brief periods when the caldera floor had risen. This happened twice in the past 500 years. The first started about a century before the last minor eruption in the caldera in 1538, which gave birth to a 134-meter mountain. The second is what volcanologists are worrying about today.

    In his office, De Natale shows me a simple line graph of the current rise. The most notable features are sharp uplifts of 1.7 meters and 1.8 meters, respectively, from 1969 to 1972 and 1982 to 1984. The latter uplift period was accompanied by numerous small earthquakes — including 600 on the worst day in 1984. On charts tracking the rate of movement of the caldera floor, the uplifts, which occurred in mere geological instants, appear as nearly vertical lines. “But look,” says De Natale excitedly, “the period of uplift from 2005 onward is totally different.” Unlike the previous instances, here the line only gradually bends upward.

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    Solfatara, a volcanic vent within Campi Flegrei’s caldera, spews sulfur-rich gases. Russ Juskalian.

    De Natale’s explanation is that the two uplift periods of the 1970s and ’80s were likely caused by magma rising from a chamber 8 kilometers underground to form a shallower sill about 4 kilometers beneath the city. As the crust strained to contain the pressure, it fractured, causing the earthquakes. But then the magma stopped moving, and, sometime around 2000, the shallower layer of magma had almost completely cooled.

    From 1985 until around 2000, the caldera slumped by nearly a meter. Since 2005, the current slow uplift has recouped much of that loss in elevation, but with less seismic activity than in previous periods.

    One view, says De Natale, is to take the uplift episodes of the 1970s, 1980s and now as independent events. The first two had deformed the ground by more than twice the uplift currently underway, so surely there wasn’t anything yet to worry about.

    But what if, De Natale says, the three periods are all connected? In that case, the caldera floor is a lot like the proverbial camel’s back: An overweight rider might cause the poor animal’s spine to arch without lasting damage. But load the camel with enough weight, and eventually even the lightest additional cargo — perhaps a single straw — will result in disaster. In a similar way, the breaking point of the caldera floor might not be determined by any single displacement, but by the total net displacement since the process started.

    If this view holds, the risk for an eruption isn’t determined by the modest uplift since 2005, but by the nearly 4 meters of uplift since 1950. That would mean the caldera is already under considerable tension. The question is how much more it could take. Even De Natale isn’t ready to say.

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    Rocks colored vibrant yellow by sulfur emissions near Solfatara. Russ Juskalian.

    A Giant’s Footprints

    To understand why Campi Flegrei poses such an unpredictable and enigmatic risk requires a removed vantage point and a history lesson. Or, as Antonio Costa, an expert on the formation of calderas tells me, “Without geological history, you cannot know the current situation.” So, after spending a few days with Chiodini and De Natale, Scholz and I join Costa and volcanologist Roberto Isaia at a mountaintop monastery with a view of the caldera and its surroundings.

    Near the back of the grounds, a stone terrace opens to the stunning vista of a semicircular valley composed of visible craters in its center — remnants of the caldera’s 70 “small” eruptions in the past 15,000 years — and beyond that the deep blue water of the Gulf of Naples.

    As Costa unrolls a topographical map of what we’re looking at, Isaia becomes animated. His fingers trace the ridge of Posillipo Hill, arcing into the ocean where the island of Ischia sits opposite us. Then he traces a line from the other side of the valley, completing an 13-kilometer-wide oval. “That,” he says, “is the volcano.”

    The sprawling, disorganized, traffic-bound mess in the middle is teeming with people. We can see Stadio San Paolo, the third-largest stadium in Italy, with a capacity of 60,000. The observatory is somewhere in there, too.

    “A new eruption could happen anywhere down there,” says Costa.

    He produces a timeline of Campi Flegrei’s periods of rest and unrest. “We don’t know if this is the start of a new epoch or not,” says Costa, noting the irregularity of its past activity.

    One risk probability map of the area we’re looking at, modeled on eruptions from the past 5,000 years, looks like a rainbow of concentric paint splatters, each larger than the next, with finger-shaped bands extending outward from an epicenter in Pozzuoli. Each color represents the annual probability of being hit by pyroclastic flows, gravity-driven currents of superheated rock and debris that move a lot like an avalanche.

    The real threat for the greater Naples area, however, is the ash that Campi Flegrei might send skyward. The prevailing wind patterns mean even moderately sized eruptions would drop the bulk of their ejected ash right on the heads of Neapolitans. Drop enough of it, and the flat roofs around the city would start collapsing.

    It’s a scenario never far from my mind over the last days of my trip. And as we finally prepare to leave Naples, I turn to Scholz and sheepishly admit that, as irrational as it might be, I feel a sense of relief to be going home.

    “Me, too,” he replies.

    Postscript or Prologue?

    Media coverage of Campi Flegrei’s potential threat erupted around the end of 2016 with the publication of Chiodini’s study. In May, the paper De Natale co-wrote raised alarms again. “Set to Blow?” read one British tabloid. “Italy’s Supervolcano May Be on a Course to Erupt,” warned another. But the caldera itself has been quiet.

    “The ground level is stable, and the seismicity almost absent,” De Natale writes via email when I ask what the fuss is about. The paper isn’t so circumspect. It postulates that Campi Flegrei’s crust may have as little as a meter left to give before “an eruption can be expected.”

    The team reached this conclusion by scrutinizing the changing patterns of small earthquakes and uplift at Campi Flegrei and analyzing physical markers of stress from a deep drilling program. They also compared the data against that of other volcanoes, notably two vents in the similarly sized Rabaul caldera in Papua New Guinea that erupted simultaneously in 1994. (Thanks to a local preparedness campaign, the eruption killed only four people.)

    Their findings offer a model for how rising magma and pockets of hot water or gas stretch the ground beneath a caldera in three distinct phases. In each phase, the ground is less elastic. The final “inelastic” phase is a sign that the crust is stretched to its limits and riddled with small fractures: rigid and ready to erupt.

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    A monitoring station keeps close tabs on activity in the caldera. Russ Juskalian.

    The current uplift, wrote the authors about Campi Flegrei, “suggests that the crust is now approaching the transition from quasi-elastic to inelastic deformation.” The caldera floor has been pushed upward by about 4 meters since 1950. The bad news is that, if their model is correct, the caldera floor should become inelastic at between 5 and 12.5 meters. The volcano’s unpredictable history and our limited understanding of how caldera volcanoes in general work make it impossible to know whether that limit could be reached in years, decades — or never.

    That leaves the people of Naples with two models in disagreement over signs of a potential imminent eruption: one from Chiodini, looking for the CDP and heat-weakened rocks, and one from De Natale, focusing on an accumulation of tension in rocks bent to their limits. To laypeople, that might sound like a reason to trust neither. However, there’s one area where the two models do agree: Campi Flegrei is acting in a way that suggests its first reawakening in 412 years.

    The long-term life cycle of caldera volcanoes is still largely a mystery, however. Instead of the tossing and turning of a waking giant, both researchers suggest that Campi Flegrei’s movements may simply stop, and the volcano sinks back into a deep sleep. The problem is that nobody will know until it erupts — or doesn’t.

    That uncertainty reminds me of the unsettled feeling I had walking the streets of Naples, knowing the chance of an eruption is statistically minuscule, but always there. But it also makes me think of what I like most about Naples: its seemingly endless capacity, no matter the conditions, to keep living.

    It’s a city flanked by volcanoes, with magma beneath its feet. Its cathedrals are literally built of volcanic ash. Almost, I think, like an act of defiance.

    See the full article here .

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  • richardmitnick 2:07 pm on December 28, 2017 Permalink | Reply
    Tags: , , , , Geology, , , The Curious Case of the Ultradeep 2015 Ogasawara Earthquake   

    From Eos: “The Curious Case of the Ultradeep 2015 Ogasawara Earthquake” 

    AGU bloc

    AGU
    Eos news bloc

    Eos

    12.28.17
    Terri Cook

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    The intensity distribution across Japan on the Japanese seven-point scale from the 680-kilometer-deep earthquake near the Ogasawara Islands. Credit: Japan Meteorological Agency

    On 30 May 2015, a powerful earthquake struck west of Japan’s remote Ogasawara (Bonin) island chain, which lies more than 800 kilometers south of Tokyo. Although it caused little damage, the magnitude 7.9 quake was noteworthy for being the deepest major earthquake ever recorded—it occurred more than 100 kilometers below any previously observed seismicity along the subducting Pacific Plate—and the first earthquake felt in every Japanese prefecture since observations began in 1884.

    The 680-kilometer-deep earthquake was also notable for its unusual ground motion. Instead of producing a band of high-frequency (>1 hertz) seismic waves concentrated along northern Japan’s east coast, as is typical for deep subduction-related earthquakes in this region, this event generated strong, low-frequency waves that jolted a broad area up to 2,000 kilometers from the epicenter. To explain this uncharacteristic wavefield, Furumura and Kennett [Journal of Geophysical Research] analyzed ground motion records from across the country and compared the results to observations from a much shallower, magnitude 6.8 earthquake that occurred within the Pacific slab in the same area in 2010.

    The results indicated that the peculiar ground motion associated with the 2015 earthquake was due to its great source depth as well as its location outside of the subducting slab. The team found that the ultradeep event was missing high-frequency components and generated milder ground motions at regional distances, whereas the 2010 earthquake included the high-frequency components but was narrowly focused.

    After contrasting three-dimensional numerical simulations of seismic wave propagation from both events, the researchers concluded that waves originating from a deep source outside of the slab can develop a distinctive, low-frequency wavefield as they interact with continental crust and the region’s subducting slabs. Because this wavefield is usually concealed by higher-frequency, slab-guided waves, the few existing examples of this phenomenon will likely provide valuable information on local crustal structure and, in the case of the 2015 Ogasawara event, the morphology of the Pacific Plate.

    See the full article here .

    IF YOU LIVE IN AN EARTHQUAKE PRONE AREA, ESPECIALLY IN CALIFORNIA, YOU CAN EASILY JOIN THE QUAKE-CATCHER NETWORK

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    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).

    BOINCLarge

    BOINC WallPaper

    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
    QCN Quake Catcher Network map

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

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    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

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    Eos is the leading source for trustworthy news and perspectives about the Earth and space sciences and their impact. Its namesake is Eos, the Greek goddess of the dawn, who represents the light shed on understanding our planet and its environment in space by the Earth and space sciences.

     
  • richardmitnick 11:20 am on December 27, 2017 Permalink | Reply
    Tags: , Geology, If there’s any consensus among geologists it is that something changed about 2.7 billion years ago to kick tectonic plates in action,   

    From COSMOS: “Plate tectonics: the hidden key to life on Earth” 

    Cosmos Magazine bloc

    COSMOS Magazine

    27 December 2017
    Richard A. Lovett

    Earth’s constantly moving crust helps keep the climate habitable. If circumstances had been only a little different, we could have ended up a barren hothouse like Venus or a frozen snowball like Mars. How did we get so lucky?

    1
    Vitalij Cerepok / Getty Images

    “Look again at that dot. That’s here. That’s home. That’s us.” Carl Sagan was moved to lyricism by the pale blue dot that Voyager 1 photographed as it exited the solar system 27 years ago. The pale blue dot is precious, and lucky.

    2
    Earth from Voyager 1

    NASA/Voyager 1

    Not only does Earth lie in the ‘Goldilocks zone’ that allows water to exist in the liquid form that life requires. It is also the only rocky planet we know of that constantly renovates its surface as its tectonic plates dive into the mantle in some places and re-emerge as molten lava in others.

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    The Earth’s rigid tectonic plates float on a playdoh-like mantle in slow, constant motion. Without this movement, the planet might well have ended up with a ‘stagnant lid’ no more conducive to sustaining life than Mars or Venus

    Many astrobiologists now think this constant renewal is just as important as liquid water for the flourishing of life as we know it.

    2
    A slice through the earth. The crust and upper mantle form the brittle lithosphere which cracks into tectonic plates. No image credit.

    The theory, explains planetary scientist Adrian Lenardic of Rice University in Houston, Texas, is that the Earth’s climate has been buffered by the recycling of carbon dioxide (CO2) from the atmosphere into the planet’s interior via mineral sequestration and then out again via volcanoes. This has kept the climate temperate even as the Sun’s heat has increased in intensity by about a third since the planet’s birth. Without this buffering, Earth might have heated so much that all the water in its oceans boiled away and huge quantities of CO2 accumulated in the atmosphere, much like Venus which has an average temperature of 462°C. Or it might never have recovered from being a snowball, remaining permanently frozen.

    Among the rocky worlds we know, Earth’s tectonics are unique. Venus and Mercury have no similar geological activity. Mars might have once, but not for billions of years. So why are we so lucky?

    According to geophysicist David Bercovici, of Yale University, models show the Earth sits right on the cusp between being a world with plate tectonics and one with a ‘stagnant lid’, like modern-day Mars or Venus. Something must have kicked it in the direction that produced a geologically active world that eventually gave birth to us. Bizarrely, even as astronomers probe planets hundreds of light-years distant, geologists still can’t precisely explain what triggered the events taking place beneath our feet.

    Tectonics derives from the Greek word ‘tektonikos’, meaning to build. It points to what we do understand about the way Earth’s surface is constantly remodelled. Our planet has a rigid shell called the lithosphere that comprises the crust and a hardened upper slice of an otherwise playdoh-like mantle (see diagram). That shell is cracked into seven large plates and a number of smaller ones that float on the mantle in slow, constant motion.

    The first inkling that continents moved dates back to the 1500s, when Flemish mapmaker Abraham Ortelius noted that the eastern and western coastlines of the Atlantic Ocean looked as if they might have once fitted together like pieces from a jigsaw puzzle.

    In 1912 German geophysicist Alfred Wegener coined the term ‘continental drift’ to describe how the lands on each side of the Atlantic had become so strangely sundered, but it wasn’t until 1963 that British marine geologists Fred Vine and Drummond Matthews provided the explanation (see Cosmos 54, p48). They realised the interior of the Earth is in motion. The rock of the mantle is slightly plastic – enough so that it can rise and fall in slow, roiling motions called convection currents: hot rock rises from the depths, cools, become denser and then descends. The best analogy is a lava lamp, which uses heat from a light bulb to induce the circulation of coloured wax in liquid. While the lava lamp’s convection currents are fast enough to produce mesmerising changes of colour, the rock of the mantle moves “about as fast as your fingernails grow”, says Bercovici – at a speed of less than 10 cm a year.

    When rising currents hit the underside of the solid lithosphere, they deflect sideways, exerting drag. If that drag is strong enough, it can rip the lithosphere apart, creating new plates and making old ones move, upwelling magma filling in the gaps. When this happens at the bottom of the ocean, the result is ‘sea floor spreading’ – which is what Vine and Matthews observed. This is occurring today in places such as the Mid-Atlantic Ridge and the Red Sea Rift between Africa and Arabia.

    As the spreading crust cools, it grows denser. Eventually the leading edge furthest from the magma flow starts sinking back into the mantle, pulling the rest of the slab behind it – a process called subduction – and so completing the convection cycle. Like the wax in the lava lamp, the cycle of rising, spreading, falling and rising again is the engine that moves the plates, and with them the continents, which ride atop like rafts.

    Though these motions occur at a rate of only a few centimetres per year, that is rapid enough to make even the oldest seafloor in the world startlingly young – less than 200 million years old. Continental crust, the buoyant crud that froths to the surface as ocean crust subducts, is much older.

    The plates do not move in the same direction or at the same speed. This causes some plates to crash into each other, driving up mountain ranges, such as the Himalayas at the collision of the Indian and Eurasian plates. They can also grind past one another, as along California’s famed San Andreas Fault. Or one can dive beneath another, as occurs at the Pacific ‘Ring of Fire’ that circles the Pacific Ocean in a belt of earthquake-prone regions and volcanic activity.

    In this process, continents tend to remain on the surface. They are too buoyant to be easily subducted into the depths. But they still play an important role via a process known as ‘weathering’, which provides a vital thermostat that has helped keep the Earth temperate for billions of years.
    Tectonic thermostat: continental weathering removes 300 million tonnes from the atmosphere each year. It’s a vital part of the carbon cycle that has kept the Earth temperate.

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    Tectonic thermostat: continental weathering removes 300 million tonnes from the atmosphere each year. It’s a vital part of the carbon cycle that has kept the Earth temperate.

    It begins when CO2 from the atmosphere dissolves in rainwater to form carbonic acid. This breaks down minerals in continental rocks, producing calcium and bicarbonate ions that wash into the sea. Marine organisms take them up to form calcium carbonate, the building block for their shells and skeletons, which ultimately settle to the seafloor and become limestone.

    Each year the process removes about 300 million tonnes of CO2 from the atmosphere. But the carbon isn’t sequestered forever, because some of that limestone is subducted along with the seabed. It heats, melts and is incorporated into magma for carbon dioxide-spewing volcanoes to release. This also produces fresh rock for the next weathering cycle.

    What makes this process function like a thermostat is that the more CO2 there is in the atmosphere, the more carbonic acid there is in rain (and the more rapidly weathering occurs). This removes CO2 from the atmosphere more swiftly, keeping the Earth from transforming into a Venusian runaway greenhouse. Conversely, if atmospheric CO2 levels fall,weathering slows, allowing volcanic CO2 to slowly build back up. It’s a slow, self-correcting process that for billions of years has kept the Earth’s temperature within a zone that is hospitable to life.

    So what got Earth’s plate tectonics going, rather than the planet ending up with a largely inert ‘stagnant lid’ like Mars and Venus?

    The earliest Earth was all magma ocean with no solid surface to form plates, let alone plates that drift around and collide with one another. At a minimum, plate tectonics couldn’t have begun until after the Earth’s surface solidified, somewhere about 4.5 to 4 billion years ago. Just when the plate tectonics kicked in, though, still has geologists squabbling.

    If you’re seeking the earliest traces of plate tectonics, a good place to look is the Jack Hills in Western Australia.

    5
    Low and smoothed by erosion, the Jack Hills aren’t too impressive as a mountain range. But mineral crystals have weathered out of the Jack Hills and washed into streams, and these crystals tell a fascinating story about how far back in Earth’s past the oceans might have formed. (NASA image by Robert Simmon, based on Landsat data provided by the Global Land Cover Facility)
    Source http://earthobservatory.nasa.gov/Study/Zircon/
    Author Robert Simmon, NASA

    6
    At the Jack Hills. U Mass Lowell.

    To the casual traveller this range of low mountains about 800 km north of Perth is not hugely impressive. But to geologists the hills are of towering significance, containing time capsules of the world’s oldest rocks in tiny crystals of zirconium silicate (ZrSiO4).

    Zircons formed in cooling magma. Three things make them geological gems. First, they carry a date stamp of formation, based on the decay of traces of uranium trapped within them. Second, they are extremely durable; the ancient volcanic rocks that gave birth to them eroded long ago and were reconstituted into sedimentary rocks in the Jack Hills’ outcrops. Third, they bear trace elements like titanium and aluminium, which reveal the conditions of their birth.

    7
    Time capsule: Jack Hills zircon. Born 4 billion years ago, it shows earth was already churning. John Valley, University Wisconsin.

    So far these zircon time capsules have telegraphed an extraordinary message: 4.2 billion years ago they were born kilometres below, crystallising as they rose to Earth’s surface. This tells us the mantle was starting to churn at that time.

    But were these upwellings the same as those that drive modern plate tectonics? Craig O’Neill thinks not. He’s a cheery geodynamicist at Sydney’s Macquarie University who has been studying Jack Hills zircons for many years. In his view, the zircons could have been formed by localised upwellings similar to those occurring today in places like Hawaii and Yellowstone. In other words, not an Earth-wide tectonic churning but a local percolation.

    Vicki Hansen, a planetary geologist at the University of Minnesota, Duluth, has come to the same conclusion based on “greenstone terranes” found in Greenland, South Africa, Canada and Scandinavia.

    These rock assemblages, which measure a few hundred kilometres across, date back to the Archaean Eon, 4 to 2.5 billion years ago. They are interesting because the greenish granites that give them their name are mixed up higgledy-piggledy with seabed sediments in ways we never see in more recent volcanic provinces. If modern-day rocks are like the vegetables displayed at the supermarket, the greenstone rocks are like stir-fry. This, Hansen says, indicates that whatever was going on in the Achaean involved processes “fundamentally different” to those today.

    More evidence that modern plate tectonics had not geared into action until relatively recently comes from the study of the history of continental drift.

    _____________________________________________________________
    If there’s any consensus among geologists, it is that something changed about 2.7 billion years ago to kick tectonic plates in action.
    _____________________________________________________________

    Supercontinents are formed when the plate-tectonic engine drives the Earth’s land masses to merge into one gigantic block. The closest we now have to a supercontinent is Eurasia. But some remarkable detective work – using the age of rocks and magnetic signatures that mark the latitudes where they first formed – reveals at least four granddaddy supercontinents that make Eurasia look tiny.

    The most recent is Pangaea, which formed about 335 million years ago and lasted through much of the age of the dinosaurs.

    It was preceded by Rodinia (1 billion to 750 million years ago), then by Nuna (2 to 1.8 billion years ago). The earliest detectable supercontinent is Kenorland (2.7 to 2.4 billion years ago), relics of which are scattered across Western Australia, North America, Greenland, Scandinavia and the Kalahari Desert.

    8
    http://www.the-dialogue.com/en/en33-earths-supercontinents/

    The fact we can’t find a supercontinent older than Kenorland may simply mean the surviving bits are too scattered for geologists to piece back together. It’s like trying to figure out the history of a vase that has been broken and reassembled several times.

    But with supercontinent formation and break-up requiring modern-style plate tectonics, the fact we haven’t found one before Kenorland might instead be telling us that for the Earth’s first 1.8 billion years the lava lamp was not strong enough to produce anything other than localised percolations, not the continent-driving process we have today.

    9
    Iceland’s lava fields: evidence of the rift between the North American and Eurasian tectonic plates. Picture Press / Getty Images

    If there’s any consensus amongst geologists, it is that something changed about 2.7 billion years ago to kick tectonic plates into action. “There appears to have been a major event,” says Kent Condie, a geochronologist at the New Mexico Institute of Mining and Technology in Socorro.

    But what could that have been? Theories range from the mundane to the dramatic, but all require the Earth to have overcome the same basic hurdles. Either the power of the lava lamp that makes mantle currents rise and swirl must have increased or the Earth’s crust must have weakened, allowing it to break into plates; or perhaps both occurred simultaneously.

    One view, favoured by Matt Welller of Rice University, is that feedback loops in magma currents gradually built up to a level strong enough to produce self-sustaining plate tectonics via what engineers call a ‘hysteresis loop’. A hysteresis loop occurs when there is a lag between cause and effect. It is analogous to an out-of-tune automobile engine. When you press down on the accelerator, at first the engine barely reacts, then it lurches forward.

    Suppose the deep convection currents driving the Earth’s plate tectonics were to suddenly shut down. That would reduce the amount of heat that can escape, causing mantle rocks to heat up and become more plastic. Softer rocks can support more vigorous convection, so the lava-lamp effect intensifies, carrying heat more rapidly from the interior –until enough has escaped, the mantle cools and its currents slow again.

    “You can shift back and forth as you heat up and cool down, heat up and cool down,” says Julian Lowman, a geodynamicist from the University of Toronto. According to this view, the juvenile Earth experienced these on-and-off episodes on a small scale, producing the localised tectonics suggested by the Jack Hills zircons and the greenstone terrains. Then, about 2.7 billion years ago, these shifts became locked into a self-sustaining Earth-wide convection cycle.

    Hansen, on the other hand, opts for a more dramatic scenario. The event that kicked off the tectonic plates might literally have been a kick – in the form of an asteroid or comet strike. Not as big as the one that formed the Moon, but far larger than the one that killed the dinosaurs.

    She first described her theory in 2007 in the journal Geology, arguing such an object would have punched right through the crust, heating the mantle and setting currents in motion, dragging the plates along with them and starting tectonic movements. Once plates began colliding and sinking, the process expanded until it spread across the planet. “Subduction is like a virus,” the paper states. “Once begun it can easily spread.”

    Alternatively, the dramatic event might have come from below. In a 2015 paper in Nature, a team led by Teras Gerya, of the Swiss Federal Institute of Technology in Zurich, argued that hot spots on the Earth’s core could have caused plumes of hot mantle to rise beneath a continent. Under the right circumstances, they calculated, this could break up the continent and cause pieces to sink, creating a self-sustaining cycle that became plate tectonics.

    __________________________________________________
    Even the strongest mantle currents wouldn’t have triggered tectonic activity if the Earth’s crust was too strong to break into plates.
    __________________________________________________

    Yet another possibility is that something changed the distribution of heat deep within the Earth. That heat comes from two sources: the long-lived radioactive decay of atoms such as uranium and thorium trapped in the mantle; and from the core, which contains a vast reservoir of heat remaining from the formation of the Earth. Both are slowly declining as the Earth ages.

    One might think a cooling Earth would have weaker tectonics. But it’s not that simple. “There are lines of research,” Lowman says, “suggesting that plate tectonics has a better chance of manifesting itself as a planet cools.” That’s because the lava-lamp engine that drives plate tectonics depends less on how hot the Earth’s interior is as on how rapidly it can transfer heat to the surface. The faster heat is transferred, the stronger the engine, and the stronger the mantle currents that drive tectonics.

    It has been known since the 1930s that the Earth’s core has two layers: an outer one composed of molten metal, and an inner one made of solid metal. As the Earth cools, the inner core grows. In the process it releases heat energy – equal to the amount it took to melt all that material in the first place. That energy rises through the core, increasing the rate at which it heats the mantle and, ultimately, rises to the surface.

    Supporting the theory that the cooling core may power the tectonic engine, a 2015 study by Condie and colleagues in the journal Precambrian Research traced the motions of continents over the past 2 billion years. They concluded that plate tectonics have been slowly speeding up, with average plate speed nearly doubling over that time.

    But even the strongest mantle currents would not have triggered tectonic activity if the Earth’s crust was too strong to break into plates. As it was, apparently, on Mars. For Berkovici, the key factor for the emergence of plate tectonics was therefore the weakening of Earth’s crust. It might have started gradually, beginning with the type of plume tectonics reflected in ancient greenstone terranes. Each of these magma breakthroughs would have created fault lines along which rocks slipped against each other, just as they do in today’s earthquakes. These motions would have produced weak spots that might have become focal points for later breakthroughs. Bercovici compares it to repeatedly bending a paper clip. “It gets softer,” he says. “Eventually you can bend it easily.”

    Gradually these weak zones would have spread until they merged into plate boundaries similar to today’s, and the process went from local and intermittent to global and continuous. “A meteor might have gotten it started,” Bercovici says in a nod to Hansen, “but it needs these feedbacks to keep going.”

    It is easy to try to fold all of this into a nice, coherent story. It would begin with a magma ocean, followed by weak, intermittent plume-style tectonics. These would eventually reach some tipping point that shifted the process to its present state, either due to changes in the core, an asteroid impact, the accumulation of Bercovici’s weak spots, or some combination of all three. But the plethora of options suggests caution.

    We may not yet have all the pieces to the puzzle. Lindy Elkins-Tanton, director of the School of Earth and Space Exploration at Arizona State University in Tempe, remembers being a graduate student at a conference, wondering what made scientists who disagreed with her own presentation so sure of themselves.

    “I sat there thinking perhaps I just didn’t know enough yet,” she recalls. “But now, 15 years later, I see that none of us know enough. We can only make small incremental progress in this very complicated problem.”

    See the full article here .

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  • richardmitnick 12:52 pm on December 26, 2017 Permalink | Reply
    Tags: , , Geology, J. William Schopf, John Valley, , , Oldest fossils ever found show life on Earth began before 3.5 billion years ago, SIMS-secondary ion mass spectrometer, Some represent now-extinct bacteria and microbes from a domain of life called Archaea, The study describes 11 microbial specimens from five separate taxa, ,   

    From U Wisconsin Madison and UCLA: “Oldest fossils ever found show life on Earth began before 3.5 billion years ago” 

    U Wisconsin

    University of Wisconsin

    UCLA bloc

    UCLA

    December 18, 2017
    Kelly April Tyrrell
    ktyrrell2@wisc.edu

    1
    Geoscience Professor John Valley, left, and research scientist Kouki Kitajima collaborate in the Wisconsin Secondary Ion Mass Spectrometer Lab (WiscSIMS) in Weeks Hall. Photo: Jeff Miller

    Researchers at UCLA and the University of Wisconsin–Madison have confirmed that microscopic fossils discovered in a nearly 3.5 billion-year-old piece of rock in Western Australia are the oldest fossils ever found and indeed the earliest direct evidence of life on Earth.

    2
    An epoxy mount containing a sliver of a nearly 3.5 billion-year-old rock from the Apex chert deposit in Western Australia is pictured at the Wisconsin Secondary Ion Mass Spectrometer Lab (WiscSIMS) in Weeks Hall. Photo: Jeff Miller

    The study, published Dec. 18, 2017 in the Proceedings of the National Academy of Sciences, was led by J. William Schopf, professor of paleobiology at UCLA, and John W. Valley, professor of geoscience at the University of Wisconsin–Madison. The research relied on new technology and scientific expertise developed by researchers in the UW–Madison WiscSIMS Laboratory.

    4
    J. William Schopf, U Wisconsin Madison

    5
    John Valley, UCLA

    2
    An example of one of the microfossils discovered in a sample of rock recovered from the Apex Chert. A new study used sophisticated chemical analysis to confirm the microscopic structures found in the rock are biological. Courtesy of J. William Schopf

    The study describes 11 microbial specimens from five separate taxa, linking their morphologies to chemical signatures that are characteristic of life. Some represent now-extinct bacteria and microbes from a domain of life called Archaea, while others are similar to microbial species still found today. The findings also suggest how each may have survived on an oxygen-free planet.

    The microfossils — so called because they are not evident to the naked eye — were first described in the journal Science in 1993 by Schopf and his team, which identified them based largely on the fossils’ unique, cylindrical and filamentous shapes. Schopf, director of UCLA’s Center for the Study of Evolution and the Origin of Life, published further supporting evidence of their biological identities in 2002.

    He collected the rock in which the fossils were found in 1982 from the Apex chert deposit of Western Australia, one of the few places on the planet where geological evidence of early Earth has been preserved, largely because it has not been subjected to geological processes that would have altered it, like burial and extreme heating due to plate-tectonic activity.

    But Schopf’s earlier interpretations have been disputed. Critics argued they are just odd minerals that only look like biological specimens. However, Valley says, the new findings put these doubts to rest; the microfossils are indeed biological.

    “I think it’s settled,” he says.

    Using a secondary ion mass spectrometer (SIMS) at UW–Madison called IMS 1280 — one of just a handful of such instruments in the world — Valley and his team, including department geoscientists Kouki Kitajima and Michael Spicuzza, were able to separate the carbon composing each fossil into its constituent isotopes and measure their ratios.

    Isotopes are different versions of the same chemical element that vary in their masses. Different organic substances — whether in rock, microbe or animal ­— contain characteristic ratios of their stable carbon isotopes.

    Using SIMS, Valley’s team was able to tease apart the carbon-12 from the carbon-13 within each fossil and measure the ratio of the two compared to a known carbon isotope standard and a fossil-less section of the rock in which they were found.

    “The differences in carbon isotope ratios correlate with their shapes,” Valley says. “If they’re not biological there is no reason for such a correlation. Their C-13-to-C-12 ratios are characteristic of biology and metabolic function.”

    Based on this information, the researchers were also able to assign identities and likely physiological behaviors to the fossils locked inside the rock, Valley says. The results show that “these are a primitive, but diverse group of organisms,” says Schopf.

    The team identified a complex group of microbes: phototrophic bacteria that would have relied on the sun to produce energy, Archaea that produced methane, and gammaproteobacteria that consumed methane, a gas believed to be an important constituent of Earth’s early atmosphere before oxygen was present.

    3
    UW–Madison geoscience researchers on a 2010 field trip to the Apex Chert, a rock formation in western Australia that is among the oldest and best-preserved rock deposits in the world. Courtesy of John Valley

    It took Valley’s team nearly 10 years to develop the processes to accurately analyze the microfossils — fossils this old and rare have never been subjected to SIMS analysis before. The study builds on earlier achievements at WiscSIMS to modify the SIMS instrument, to develop protocols for sample preparation and analysis, and to calibrate necessary standards to match as closely as possible the hydrocarbon content to the samples of interest.

    In preparation for SIMS analysis, the team needed to painstakingly grind the original sample down as slowly as possible to expose the delicate fossils themselves — all suspended at different levels within the rock and encased in a hard layer of quartz — without actually destroying them. Spicuzza describes making countless trips up and down the stairs in the department as geoscience technician Brian Hess ground and polished each microfossil in the sample, one micrometer at a time.

    Each microfossil is about 10 micrometers wide; eight of them could fit along the width of a human hair.

    Valley and Schopf are part of the Wisconsin Astrobiology Research Consortium, funded by the NASA Astrobiology Institute, which exists to study and understand the origins, the future and the nature of life on Earth and throughout the universe.

    Studies such as this one, Schopf says, indicate life could be common throughout the universe. But importantly, here on Earth, because several different types of microbes were shown to be already present by 3.5 billion years ago, it tells us that “life had to have begun substantially earlier — nobody knows how much earlier — and confirms it is not difficult for primitive life to form and to evolve into more advanced microorganisms,” says Schopf.

    Earlier studies by Valley and his team, dating to 2001, have shown that liquid water oceans existed on Earth as early as 4.3 billion years ago, more than 800 million years before the fossils of the present study would have been alive, and just 250 million years after the Earth formed.

    “We have no direct evidence that life existed 4.3 billion years ago but there is no reason why it couldn’t have,” says Valley. “This is something we all would like to find out.”

    UW–Madison has a legacy of pushing back the accepted dates of early life on Earth. In 1953, the late Stanley Tyler, a geologist at the university who passed away in 1963 at the age of 57, was the first person to discover microfossils in Precambrian rocks. This pushed the origins of life back more than a billion years, from 540 million to 1.8 billion years ago.

    “People are really interested in when life on Earth first emerged,” Valley says. “This study was 10 times more time-consuming and more difficult than I first imagined, but it came to fruition because of many dedicated people who have been excited about this since day one … I think a lot more microfossil analyses will be made on samples of Earth and possibly from other planetary bodies.”

    See the full U Wisconsin article here .
    See the full uCLA article by Stuart Wolpert here.
    Please help promote STEM in your local schools.

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    UC LA Campus

    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

    In achievement and prestige, the University of Wisconsin–Madison has long been recognized as one of America’s great universities. A public, land-grant institution, UW–Madison offers a complete spectrum of liberal arts studies, professional programs and student activities. Spanning 936 acres along the southern shore of Lake Mendota, the campus is located in the city of Madison.

     
    • stewarthoughblog 1:44 am on December 27, 2017 Permalink | Reply

      Schopf’s wishful speculation that what was discovered indicates life must be common is intellectually insulting with his failure that somehow live emerged rapidly, which strains the slow, methodical Darwinian theory of how life developed, given the relative complexity of the microorganisms. This is a wonderful discovery, but does nothing to solve the origin of life and raises serious questions about the power of naturalism to explain the origin of life as well as the rapid development of higher order complex organisms.

      The only extraterrestrial organisms that will be found will be those of Earth origin.

      Like

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