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  • richardmitnick 3:53 pm on June 3, 2021 Permalink | Reply
    Tags: "Some Forams Could Thrive with Climate Change Metabolism Study Finds", , , , Geophysics, , , Women in STEM-Joan Bernhard and Fatma Gomaa,   

    From Woods Hole Oceanographic Institution (US) : Women in STEM-Joan Bernhard and Fatma Gomaa “Some Forams Could Thrive with Climate Change Metabolism Study Finds” 

    From Woods Hole Oceanographic Institution (US)

    May 27, 2021

    Media Relations Office
    (508) 289-3340

    Light micrograph of the benthic foraminifer Nonionella stella, which thrives in anoxic sulfidic sediments far below the euphotic zone. Individuals are ~225 microns in diameter. Image credit: J.M. Bernhard.

    With the expansion of oxygen-depleted waters in the oceans due to climate change, some species of foraminifera (forams, a type of protist or single-celled eukaryote) that thrive in those conditions could be big winners, biologically speaking.

    A new paper that examines two foram species found that they demonstrated great metabolic versatility to flourish in hypoxic and anoxic sediments where there is little or no dissolved oxygen, inferring that the forams’ contribution to the marine ecosystem will increase with the expansion of oxygen-depleted habitats.

    In addition, the paper found that the multiple metabolic strategies that these forams exhibit to adapt to low and no oxygen conditions are changing the classical view about the evolution and diversity of eukaryotes. That classical view hypothesizes that the rise of oxygen in Earth’s system led to the acquisition of oxygen-respiring mitochondria, the part of a cell that generates most of the chemical energy that powers a cell’s biochemical reactions. The forams in the study represent “typical” mitochondrial-bearing eukaryotes. However, these two forams respire nitrate and produce energy in the absence of oxygen, with one colonizing an anoxic environment, often with high levels of hydrogen sulfide, a chemical compound typically toxic to eukaryotes.

    “Benthic foraminifera represent truly successful microbial eukaryotes with diverse and sophisticated metabolic adaptive strategies” that scientists are just beginning to discover, the authors noted in the paper, Multiple integrated metabolic strategies allow foraminiferal protists to thrive in anoxic marine sediments appearing in Science Advances.

    This is important because scientists have studied forams extensively for interpreting past oceanographic and climate conditions. Scientists largely have assumed that forams evolved after oxygen was on the planet and likely require oxygen to survive. However, finding that forams can perform the processes described “throws a whole new wrench in interpretations of past environmental conditions on Earth, driven by the foram fossil record,” said co-author and project leader Joan Bernhard, senior scientist in the Geology and Geophysics Department at the Woods Hole Oceanographic Institution (WHOI).

    Bernhard said that over the past several decades she has worked to establish that forams can live where there is little or no oxygen. “We never knew exactly why forams can live where there isn’t any oxygen until molecular methods got good enough that we could really start to ask some of these questions. This is our first paper that’s coming out with some of these insights,” she said. Bernhard added that with thousands of foram species living today, and with hundreds of thousands extinct, it is likely that this is “the tip of the iceberg” in terms of possibly discovering other metabolic strategies invoked by these forams.

    Specific insights from the paper pertain to two highly successful benthic foraminiferal species that inhabit hypoxic or anoxic sediments in the Santa Barbara Basin, a sort of natural laboratory off the coast of California for studying the impact of oxygen depletion in the ocean.

    Through gene expression analysis of the two species—Nonionella stella and Bolivina argentea—scientists found different successful metabolic adaptations that allowed the forams to succeed in oxygen-depleted marine sediments and identified candidate genes involved in anaerobic respiration and energy metabolism.

    The N. stella is a sort of kleptomaniac, utilizing a technique to steal chloroplasts—the structure in a cell where photosynthesis occurs—from a particular diatom genus. What makes this particularly interesting is that N. stella lives well below what is considered to be the zone where photosynthesis can happen. The authors noted that there has been discussion in the literature questioning the functionality of these kleptoplasts in the Santa Barbara Basin N. stella but the new results show that these kleptoplasts are firmly functional, although exact metabolic details remain elusive.

    In addition, the scientists found that the two foram species in the study use different metabolic pathways to incorporate ammonium into organic nitrogen in the form of glutamate, a metabolic strategy that was not previously known to be performed by these organisms.

    “The metabolic variety suggests that at least some species of this diverse protistan group will withstand severe deoxygenation and likely play major roles in oceans affected by climate change,” the authors wrote.

    The study “gives the scientific community a new direction for research,” said lead author Fatma Gomaa, who, at the time of the study, was a postdoctoral investigator at the Geology and Geophysics Department at WHOI. “We are now starting to learn that there are microeukaryotes living in habitats similar to those in Earth’s early history that are performing very interesting biological functions. Learning about these forams is very intriguing and will shed light on how early eukaryotes evolved.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Woods Hole Oceanographic Institute

    Mission Statement

    The Woods Hole Oceanographic Institution (US) is dedicated to advancing knowledge of the ocean and its connection with the Earth system through a sustained commitment to excellence in science, engineering, and education, and to the application of this knowledge to problems facing society.

    Vision & Mission

    The ocean is a defining feature of our planet and crucial to life on Earth, yet it remains one of the planet’s last unexplored frontiers. For this reason, WHOI scientists and engineers are committed to understanding all facets of the ocean as well as its complex connections with Earth’s atmosphere, land, ice, seafloor, and life—including humanity. This is essential not only to advance knowledge about our planet, but also to ensure society’s long-term welfare and to help guide human stewardship of the environment. WHOI researchers are also dedicated to training future generations of ocean science leaders, to providing unbiased information that informs public policy and decision-making, and to expanding public awareness about the importance of the global ocean and its resources.

    The Institution is organized into six departments, the Cooperative Institute for Climate and Ocean Research, and a marine policy center. Its shore-based facilities are located in the village of Woods Hole, Massachusetts(US) and a mile and a half away on the Quissett Campus. The bulk of the Institution’s funding comes from grants and contracts from the National Science Foundation(US) and other government agencies, augmented by foundations and private donations.

    WHOI scientists, engineers, and students collaborate to develop theories, test ideas, build seagoing instruments, and collect data in diverse marine environments. Ships operated by WHOI carry research scientists throughout the world’s oceans. The WHOI fleet includes two large research vessels (R/V Atlantis and R/V Neil Armstrong); the coastal craft Tioga; small research craft such as the dive-operation work boat Echo; the deep-diving human-occupied submersible Alvin; the tethered, remotely operated vehicle Jason/Medea; and autonomous underwater vehicles such as the REMUS and SeaBED.

    WHOI offers graduate and post-doctoral studies in marine science. There are several fellowship and training programs, and graduate degrees are awarded through a joint program with the Massachusetts Institute of Technology(US). WHOI is accredited by the New England Association of Schools and Colleges. WHOI also offers public outreach programs and informal education through its Exhibit Center and summer tours. The Institution has a volunteer program and a membership program, WHOI Associate.

    On October 1, 2020, Peter B. de Menocal became the institution’s eleventh president and director.


    In 1927, a National Academy of Sciences(US) committee concluded that it was time to “consider the share of the United States of America in a worldwide program of oceanographic research.” The committee’s recommendation for establishing a permanent independent research laboratory on the East Coast to “prosecute oceanography in all its branches” led to the founding in 1930 of the Woods Hole Oceanographic Institution(US).

    A $2.5 million grant from the Rockefeller Foundation supported the summer work of a dozen scientists, construction of a laboratory building and commissioning of a research vessel, the 142-foot (43 m) ketch R/V Atlantis, whose profile still forms the Institution’s logo.

    WHOI grew substantially to support significant defense-related research during World War II, and later began a steady growth in staff, research fleet, and scientific stature. From 1950 to 1956, the director was Dr. Edward “Iceberg” Smith, an Arctic explorer, oceanographer and retired Coast Guard rear admiral.

    In 1977 the institution appointed the influential oceanographer John Steele as director, and he served until his retirement in 1989.

    On 1 September 1985, a joint French-American expedition led by Jean-Louis Michel of IFREMER and Robert Ballard of the Woods Hole Oceanographic Institution identified the location of the wreck of the RMS Titanic which sank off the coast of Newfoundland 15 April 1912.

    On 3 April 2011, within a week of resuming of the search operation for Air France Flight 447, a team led by WHOI, operating full ocean depth autonomous underwater vehicles (AUVs) owned by the Waitt Institute discovered, by means of sidescan sonar, a large portion of debris field from flight AF447.

    In March 2017 the institution effected an open-access policy to make its research publicly accessible online.

    The Institution has maintained a long and controversial business collaboration with the treasure hunter company Odyssey Marine. Likewise, WHOI has participated in the location of the San José galleon in Colombia for the commercial exploitation of the shipwreck by the Government of President Santos and a private company.

    In 2019, iDefense reported that China’s hackers had launched cyberattacks on dozens of academic institutions in an attempt to gain information on technology being developed for the United States Navy. Some of the targets included the Woods Hole Oceanographic Institution. The attacks have been underway since at least April 2017.

  • richardmitnick 1:57 pm on April 23, 2021 Permalink | Reply
    Tags: "Fiber Optic Cable Monitors Microseismicity in Antarctica", , Geophysics, , The movement and deformation of the ice under changing climate conditions.   

    From Seismological Society of America (US) : “Fiber Optic Cable Monitors Microseismicity in Antarctica” 

    From Seismological Society of America (US)

    23 April 2021

    At the Seismological Society of America’s 2021 Annual Meeting, researchers shared how they are using fiber optic cable to detect the small earthquakes that occur in ice in Antarctica.

    The results could be used to better understand the movement and deformation of the ice under changing climate conditions, as well as improve future monitoring of carbon capture and storage projects, said Anna Stork, a geophysicist at Silixa Ltd.

    Stork discussed how she and her colleagues are refining their methods of distributed acoustic sensing, or DAS, for microseismicity—earthquakes too small to be felt. DAS works by using the tiny internal flaws within an optical fiber as thousands of seismic sensors. An instrument at one end sends laser pulses down the cable and measures the “echo” of each pulse as it is reflected off the fiber’s internal flaws.

    Building a DAS system in Antarctica. | Michael Kendall.

    When the fiber is disturbed by earthquakes or icequakes, there are changes in the size, frequency and phase of laser light scattered back to the DAS receiver that can be used characterize the seismic event.

    Michael Kendall of the University of Oxford (UK) said the Antarctic research demonstrates how DAS can be used to monitor underground carbon capture and storage at other sites in the world. For instance, the layout of the Antarctic network offers a good example for how a similar network could be configured to best detect microseismicity that could be triggered by carbon storage.

    “Our work also demonstrates a method of using DAS fiber arrays to investigate microseismic earthquake source mechanisms in more detail than conventional geophones,” said Tom Hudson of the University of Oxford. “If we can analyze the source mechanism—how an earthquake fails or fractures—then we may be able to attribute the earthquake to the movement of fluids like carbon dioxide in a reservoir.”

    The Antarctic microseismic icequakes recorded by DAS “are approximately magnitude -1, corresponding to approximately the size of a book falling off a table,” Hudson explained, “so they are very small earthquakes.”

    The study by Hudson and colleagues is the first to use DAS to look at icequakes in Antarctica. The fiber optic cable was deployed in a linear and triangular configuration on the ice surface at the Rutford Ice Stream.

    Kendall said there are a number of challenges to using fiber optic sensors in the harsh Antarctica environment. The equipment had to travel in pieces by boat and several planes to the study site. The researchers had to bury the fiber to reduce wind noise contaminating the seismic signal, as well as remove the signal of a generator that powered the DAS instrument.

    “We housed the instrument in a mountaineering tent, which basically served as a tiny office,” Stork explained. “Keeping temperatures within the recommended operating limits was a challenge. The radiative heating from the sun warned the tent to well in the 30s [degrees Celsius], even though it was -10 degrees Celsius outside.”

    The researchers share their analyses of icequake data with climatologists and other researchers studying the slip of glaciers and other ice movements in Antarctica, Kendall said.

    “Hopefully in the future we will interact more with scientists drilling ice cores too, as they use fiber as distributed temperature sensors, but these fibers that they put down boreholes could also be used for seismic studies like ours,” he noted.

    See the full article here.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The Seismological Society of America (US) is an international scientific society devoted to the advancement of seismology and the understanding of earthquakes for the benefit of society. Founded in 1906, the society has members throughout the world representing seismologists and other geophysicists, geologists, engineers, insurers, and policy-makers in preparedness and safety.

    The society was established by academic, government, and other scientific and engineering professionals in the months following the April 18th San Francisco earthquake, with the first meeting of the Board of Directors taking place on December 1, 1906.

    The Seismological Society of America publishes the Bulletin of the Seismological Society of America (BSSA), a journal of research in earthquake seismology and related disciplines since 1911, and Seismological Research Letters (SRL), which serves as a forum for informal communication among seismologists, as well as between seismologists and those non-specialists interested in seismology and related disciplines.

  • richardmitnick 9:39 pm on April 22, 2021 Permalink | Reply
    Tags: "‘Like a metronome’- stalagmite growth found to be surprisingly constant", , , , , Geophysics   

    From University of New South Wales (AU) : “‘Like a metronome’- stalagmite growth found to be surprisingly constant” 

    U NSW bloc

    From University of New South Wales (AU)

    23 Apr 2021
    Lachlan Gilbert

    To look inside a stalagmite is to look back in time tens of thousands of years to see how the Earth’s climate patterns have shaped the world we live in today.

    Stalagmites on average have grown one metre over the last 11,000 years. These two are in Yonderup Cave, Yanchep, Western Australia. Photo: Andy Baker/UNSW.

    Like tree rings, cave stalagmites are a portal to a prehistoric Earth, and now scientists from UNSW Sydney have found they are consistently reliable as time trackers the world over.

    In a global investigation into the growth properties of stalagmites distributed across the world, the scientists found that while growth fluctuations due to climate events are evident in the shorter period, stalagmite growth over the longer periods – tens of thousands of years – are surprisingly linear.

    “Our new global analysis shows that we can consider stalagmite growth as being like a metronome and very constant over hundreds and thousands of years,” says Professor Andy Baker, UNSW School of Biological, Earth and Environmental Sciences.

    “Sometimes extreme weather events can disturb this metronome for a few years, making the growth a bit faster or slower, and we can use that to explore climate variations.

    “But in general, stalagmite growth is predictable and it is this unique property that makes them so valuable to researchers – you can tell the time in the past by using the very regular growth rings that are widely present across the globe.”

    Stalagmites, which grow from cave floors as water drips from stalactites at the cave ceiling, are the result of chemicals carried by the water in solution that turns to solid form in the cave. They are built by layers of calcite crystals, which may be perfectly stacked one on top of the other if nothing disturbs the growth.

    “But in reality, there are many disturbances in caves,” says Prof. Baker.

    “Tiny particles from the soil above and trace elements of chemicals can disturb the stacking to create pores between growing crystals or even slightly change their shape in the morphology – or fabric – of the growing crystals.”

    Steady growth

    Scientists have used stalagmites as gauges of different parts of the planet’s conditions over millennia for some time, but whether all stalagmites grew the same way in caves of different climatic conditions remained unknown – until now.

    An X‐ray fluorescence map of a cross section of a stalagmite from the Cook Islands. Each dark blue band marks the onset of the wet season. Image: Andrea Borsato, Silvia Frisia/Australian Synchrotron, Victoria

    “Before this analysis, we did not have evidence that stalagmites are only found in regions with seasonal precipitation, nor was it obvious that the stalagmite growth rate is relatively unchanging over time and that this is a ubiquitous property,” Prof. Baker says.

    “What we have learned is that for an environmental signal to be preserved in stalagmite laminae thickness variations, a large perturbation to weather patterns is required – such as prolonged wet or dry years associated El Niño or La Niña.

    “But in regions where there is a seasonality of precipitation, the long-term constant growth rate of laminated stalagmites provides an unparalleled capacity for precise chronology building.”

    The researchers found that between different locations around the world, warmer climates tended towards more stalagmite growth over time, while colder climates saw growth slowed.

    But the research showed that the majority of stalagmite samples, irrespective of location, followed a linear growth over the timescale of tens of thousands of years.

    “The ‘global average stalagmite’ increased in height by about one metre over the last 11,000 years,” Prof. Baker says.

    Snapshot of the past

    Analysing the way the laminae are organised can help scientists read environmental conditions and weather events of the distant past. In seasonal climates, these changes in the fabric can occur at regular intervals, producing layers they call ‘annually laminated stalagmites’. But when extreme weather events occur, as happens with the El Niño/La Niña Southern Oscillation phenomenon involving mega-droughts, bushfires and flooding events, variations of thicknesses of stalagmite laminae can provide vital clues.

    “We can use other chemical evidence in stalagmites to obtain records of past environmental change, and know exactly when this happened,” says Prof. Baker.

    “For example, at UNSW we are reconstructing fire histories from cave stalagmites for the first time. Working in Western Australia, and using stalagmites that have these continuous laminae and regular growth, we can identify how often fires have occurred in the past from the traces left behind from the soluble part of bushfire ash that gets transported to the stalagmite by drip water.”

    The researchers say that they still have limited understanding on how crystals grow within each lamina, so future studies could investigate the internal structure of the laminae and the crystal growth mechanisms involved.

    The analysis was published in the April issue of Reviews of Geophysics journal.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    U NSW Campus

    Welcome to UNSW Australia (AU) (The University of New South Wales), one of Australia’s leading research and teaching universities. At UNSW, we take pride in the broad range and high quality of our teaching programs. Our teaching gains strength and currency from our research activities, strong industry links and our international nature; UNSW has a strong regional and global engagement.

    In developing new ideas and promoting lasting knowledge we are creating an academic environment where outstanding students and scholars from around the world can be inspired to excel in their programs of study and research. Partnerships with both local and global communities allow UNSW to share knowledge, debate and research outcomes. UNSW’s public events include concert performances, open days and public forums on issues such as the environment, healthcare and global politics. We encourage you to explore the UNSW website so you can find out more about what we do.

  • richardmitnick 1:00 pm on April 8, 2021 Permalink | Reply
    Tags: "A song of ice and fiber", , , , Geophysics, Sandia National Laboratories researchers are beginning to analyze the first seafloor dataset from under Arctic sea ice using a novel method.   

    From DOE’s Sandia National Laboratories (US) : “A song of ice and fiber” 

    From DOE’s Sandia National Laboratories (US)

    April 8, 2021

    Manette Fisher

    A rare, peaceful sunrise at Oliktok Point during the first week of February, when Sandia National Laboratories researchers began collecting the first-ever dataset from the Arctic seafloor using distributed acoustic sensing and a fiber optic cable. To listen to and download a clip of a suspected ice quake captured during the first experiment. Credit: Kyle Jones.

    Sandia National Laboratories researchers are beginning to analyze the first seafloor dataset from under Arctic sea ice using a novel method. They were able to capture ice quakes and transportation activities on the North Slope of Alaska while also monitoring for other climate signals and marine life.

    The team, led by Sandia geophysicist Rob Abbott, connected an iDAS, a distributed acoustic sensing interrogator system manufactured by Silixa, to an existing fiber optic cable owned by Quintillion, an Alaska-based telecommunications company. The cable reaches the seafloor from Oliktok Point. For seven days, 24 hours a day, cable vibrations were captured and recorded, helping researchers better understand what natural and human-caused activity takes place within the data-starved ocean.

    This is the first time a distributed acoustic sensing interrogator system had been used to capture data on the seafloor of the Arctic or Antarctic oceans, and the team sees many advantages for future use.

    “This is a first-of-its-kind data collect, and as far as what national laboratories do, this is exactly the type of high-risk, high-reward research that could make a huge difference in how we’re able to monitor the Arctic Ocean,” said Sandia manager Kyle Jones. “This really is on the cutting edge of seismology and geophysics, along with climate change and other disciplines.”

    The team is expecting to record climate signals like the timing and distribution of sea ice breakup, ocean wave height, sea ice thickness, fault zones and storm severity. Shipping, whale songs and breaching can also be recorded. This new way of monitoring holds the potential to persistently capture a wide variety of Arctic phenomena in a cost-effective and safe manner so that scientists can better understand the effects of climate change on this fragile environment, Abbott said.

    The interrogator looks like an electronic box that can be attached to the fiber optic cable on land, and it uses a laser to send thousands of short pulses of light along the cable every second. A small proportion of that light is reflected back — or backscattered — along the cable as the seafloor it’s attached to moves due to earth, sea ice, ocean current and animal activities. The backscattered light enables the interrogator to detect, monitor and track events along the fiber, and data is stored on hard drives.

    “Quintillion’s fiber optic cable is in a favorable place on the North Slope of Alaska,” Abbott said. “This technology works for this project for several reasons. We are not sending a boat out to plant monitors; we’re not traipsing over the sea ice trying to install sensors. This cable will exist for decades and we can take good data on it. It’s a very safe way of taking this measurement in a hazardous environment.”

    Funded by the Laboratory Directed Research and Development program, this was the first of eight week-long data collection that will happen over the next two years during the project. The team will visit Alaska in each of the four Arctic seasons defined as ice-bound, ice-free, freezing and thawing. A third year will be spent further analyzing data.

    Abbott said results will be communicated with the broader scientific community and will be provided to the climate modeling community for inclusion in algorithms. Additionally, the team hopes the results of the project will show the need for persistent distributed acoustic sensing monitoring in the Arctic.

    “We’d like to provide data to high-fidelity climate models and raw data analysis,” Abbott said. “I’m also hoping to conduct a direct measurement of sea ice thickness, which is currently difficult. Right now, you need an airplane flying over or you need to go out on the ice. That can be very dangerous and expensive, and you can only do it once or twice a year. Using a fiber optic cable, the distributed acoustic sensing system could be out there 24/7/365 and you could potentially take a sea ice thickness measurement once per day.”

    Encouraging data captured in first 168 hours

    Sandia researchers are just starting to analyze the first 168 hours of data collected in February, and they are encouraged by what they see, Abbott said.

    “We see things that are indicative of ice quakes. We see events as far out as 33 kilometers in the ocean where there should be no anthropogenic activity,” he said, referring to the first two hours of data he’d looked at. “We’re certainly seeing a natural event of some sort. It could be an ice quake, or it could be a micro-seismic event in the ground like an earthquake. We’re not sure yet.”

    Closer to shore, Abbott said the team most likely recorded production and reinjection wells recycling wastewater and frequencies that are indicative of ocean tides and currents. One surprising result was the system picking up frequencies of a low-flying hover craft.

    The interrogator can record events at a spatial density of three to four orders-of-magnitude greater than traditional hydrophone or ocean bottom seismometer deployments, Abbott said.

    “In this first data collect, we weren’t expecting to see a lot of currents and ice quakes because there was stable ice cover over the entire area, and yet we do see some of those things, which is exciting,” Abbott said.

    Abbott said he’s looking forward to capturing data on whales and seals during the migrating season. The Arctic is home to bowhead and beluga whales, each having individual songs. The system should be able to record these songs in the same manner as recording earthquakes because vibrations in the ocean are transmitted to the earth, which is then transmitted to the cable. With whales, a characteristic pattern develops as the song changes pitch.

    “It’s called gliding, where over time, the frequencies start out low and go high and back down,” Abbott said. “Frequencies like that are characteristic of biological sources and are easily discriminated from other sources, such as earthquakes. Whales often sing for over 30 minutes with individual repeated notes that last a few seconds long that glide up and down.”

    North Slope weather added intensity to experiment’s critical first week

    Sandia National Laboratories geophysicist Rob Abbott said one of the challenges of working in the Arctic is the expected but frigid temperatures. Credit: Kyle Jones.

    The expected but fierce North Slope climate was a challenge. In February, the area is dark about 18 hours of the day and because snow blows much of the time and roads aren’t well marked, everything continues to look new, Abbott said. The team was also dealing with bitter cold, and while they were prepared, temperatures were about 10 degrees colder than expected, at one point dropping to minus 45 Fahrenheit (minus 77 including windchill). Even the people who work there for a living shut down all outdoor activities, Abbott said.

    “The American Arctic is formidable, 30 degrees below zero being a common occurrence in the winter months,” said Michael McHale, Quintillion’s chief revenue officer. “Much of the region is tundra and difficult to traverse in the best of weather. Working here requires significant experience and hard-won expertise. The engineering implications are enormous. Most networks and satellite ground stations do not operate in regions where they need to be able to tolerate 70 degrees below zero.”

    Due to harsh conditions, Quintillion’s fiber optic cable is double-armored with copper and steel sheathing to protect against cutting, crushing or abrasion damage, McHale said.

    “All of the company’s network components, including the cabling, are engineered to withstand the extreme Arctic environment and protect against network outages,” he added. “The subsea portions of the cable are primarily buried below the seabed.”

    Nerves lasted throughout week as successful data collection was uncertain

    The day after the team arrived, researchers met at the Quintillion cable landing facility where the distributed acoustic sensing system was installed with the help of the company. A team member from Silixa, the company Sandia purchased the distributed acoustic sensing system from, was also there to assist.

    Sandia researchers were able to utilize about 30 miles of the subsea fiber optic cabling, McHale said, and setup went smoothly. He added that the project has been a great experience so far.

    “The opportunity to work with some of the most knowledgeable geophysicists and data scientists in the country is exciting and an honor,” he said. “Supporting the work of the scientific community has long been a goal of Quintillion’s. Accomplishing that goal with a client as highly regarded as Sandia Labs exceeded our expectations.”

    During the first few days of the initial collection, there was anticipated nervousness among the team because this was something that hadn’t been done before. While Abbott has used fiber optic cables to record explosions for Sandia, he hadn’t used them on a seabed nor for something this large.

    The interrogator gathers 2 gigabytes of information per minute, and because it’s coming in so fast, it’s difficult to know whether the data is good, Abbott said. After three or four days, the team had indications that the system was working well, and it took the entire week before they felt confident about the experiment.

    “What I’m excited for is we see a lot of interesting phenomena in this data collection, which will probably be the quietest dataset with the fewest amount of ice quakes or wave action,” Abbott said. “Once we start to see the ice break up and icebergs crashing into each other in other seasons when there’s no ice up there at all, we’ll see things better like tides, currents and storms.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sandia Campus.

    DOE’s Sandia National Laboratories (US) managed and operated by the National Technology and Engineering Solutions of Sandia (a wholly owned subsidiary of Honeywell International), is one of three National Nuclear Security Administration(US) research and development laboratories in the United States. Their primary mission is to develop, engineer, and test the non-nuclear components of nuclear weapons and high technology. Headquartered in Central New Mexico near the Sandia Mountains, on Kirtland Air Force Base in Albuquerque, Sandia also has a campus in Livermore, California, next to DOE’sLawrence Livermore National Laboratory(US), and a test facility in Waimea, Kauai, Hawaii.

    It is Sandia’s mission to maintain the reliability and surety of nuclear weapon systems, conduct research and development in arms control and nonproliferation technologies, and investigate methods for the disposal of the United States’ nuclear weapons program’s hazardous waste.

    Other missions include research and development in energy and environmental programs, as well as the surety of critical national infrastructures. In addition, Sandia is home to a wide variety of research including computational biology; mathematics (through its Computer Science Research Institute); materials science; alternative energy; psychology; MEMS; and cognitive science initiatives.

    Sandia formerly hosted ASCI Red, one of the world’s fastest supercomputers until its recent decommission, and now hosts ASCI Red Storm supercomputer, originally known as Thor’s Hammer.

    ASCI Red Storm Cray superrcomputer at DOE’s Sandia National Laboratory

    Sandia is also home to the Z Machine.

    Sandia Z machine.

    The Z Machine is the largest X-ray generator in the world and is designed to test materials in conditions of extreme temperature and pressure. It is operated by Sandia National Laboratories to gather data to aid in computer modeling of nuclear guns. In December 2016, it was announced that National Technology and Engineering Solutions of Sandia, under the direction of Honeywell International, would take over the management of Sandia National Laboratories starting on May 1, 2017.

  • richardmitnick 12:58 pm on January 9, 2021 Permalink | Reply
    Tags: "Two UCSC geophysicists honored by Royal Astronomical Society", , , Emily Brodsky-The Price Medal for single investigations or a series of closely linked investigations of outstanding merit., Geophysics, Royal Astronomical Society (RAS) medals awarded to two UCSC scentists., Thorne Lay-Gold Medal for Geophysics.,   

    From UC Santa Cruz: “Two UCSC geophysicists honored by Royal Astronomical Society” 

    From UC Santa Cruz

    January 08, 2021
    Tim Stephens

    The Royal Astronomical Society (RAS) is honoring two seismologists at UC Santa Cruz for their research contributions in geophysics.

    Thorne Lay, distinguished professor of Earth and planetary sciences, was awarded the Gold Medal for Geophysics “in recognition of his outstanding work in seismological analysis, which has had an exceptional impact on our perceptions of the structure and dynamics of the Earth.”

    Thorne Lay

    Emily Brodsky, professor of Earth and planetary sciences, was awarded the Price Medal “in recognition of her outstanding multi-disciplinary contributions to earthquake mechanics, frictional behavior, and rock-fluid interactions.”

    Emily Brodsky

    The Gold Medal is the RAS’s highest honor and is often awarded as recognition of a lifetime’s work. Lay’s achievements began with his Ph.D. studies of the structure of the deep mantle, which revealed a discontinuity a few hundred kilometers above the core-mantle boundary, implying great structural complexity with profound geodynamic consequences. This pioneering work has been the cornerstone for a diverse creative range of interdisciplinary studies in which he has been a leader, from mineral physics to the fate of subducted slabs and the potential genesis of mantle plumes.

    Lay’s research has also provided new insights into the rupture processes of the world’s most devastating earthquakes and the generation of tsunamis. He has published hundreds of papers, inspiring generations of graduate students, post-docs, and researchers all over the world. As a leader of the seismological community, he was critical to the success of the Incorporated Research Institutions for Seismology (IRIS), which archives and distributes the world’s earthquake data. He was elected chair of IRIS’s Board of Directors, has served on panels on Comprehensive Nuclear Test Ban Treaty Research, and was president of the International Association of Seismology and Physics of the Earth’s Interior (IASPEI).

    The Price Medal is awarded for single investigations or a series of closely linked investigations of outstanding merit into the formation and composition of the Earth or planets. Brodsky is an internationally acknowledged leader in quantifying processes involved in generating and propagating earthquake ruptures. Her primary recent research targets have included observational approaches to measuring stress on faults, analysis of human-induced earthquakes, experimental work on granular flows at high slip rates, and analysis of aftershock distributions relative to fault ruptures and volcanic processes.

    Using novel combinations of field measurements, laboratory experiments, observational seismology, and theoretical modeling, Brodsky’s research often provides comprehensive insights into the problems she is tackling. To test models for fault friction at the field scale, she argued that the ruptured fault should be drilled as soon as possible after an earthquake. The JFAST rapid response drilling into the seafloor disrupted by the magnitude 9 Tohoku earthquake provided the required data. Her work showed that dynamic weakening in already weak clay material on the plate boundary occurred for the Tohoku rupture. Using down-hole thermal observatories, she has also detected fluid pressure redistributions in the damage zone around the main boundary faults. In announcing the Price Medal, the RAS noted that the novelty of her approaches and the importance of her work sets Brodsky apart.

    The RAS announced the 2021 awards at the Ordinary Meeting of the Society held on Friday, January 8. The winners will be invited to collect their awards at the RAS National Astronomy Meeting in July.

    “I’m delighted that we can recognize the wealth of talent in astronomy and geophysics through our prestigious awards and medals,” said RAS President Professor Emma Bunce. “In the midst of a challenging time, we should not lose sight of the achievements of the stars of our science community, inspiring us by answering the deep questions about the Earth beneath our feet and the Universe around us. My congratulations to all the winners!”

    See the full article here .


    Please help promote STEM in your local schools.

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    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

    UCSC Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft).

    UC Observatories Lick Automated Planet Finder, fully robotic 2.4-meter optical telescope at Lick Observatory, situated on the summit of Mount Hamilton, east of San Jose, California, USA.

    The UCO Lick C. Donald Shane telescope is a 120-inch (3.0-meter) reflecting telescope located at the Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft).

    UC Santa Cruz campus.

    UCSC is the home base for the Lick Observatory.

    Lick Observatory’s 36-inch Great Great Refractor telescope housed in the South (large) Dome of main building.

  • richardmitnick 11:50 am on November 20, 2020 Permalink | Reply
    Tags: "Scientists Uncover the Universal Geometry of Geology", Any rocks that broke randomly would crack into shapes that have on average six faces and eight vertices., , Geophysics, Plato was right: On average the world is made out of cubes., , Several geophysicists contacted by Quanta say the same mathematical framework might also help with problems like understanding erosion from cracked cliff faces or preventing hazardous rock slides.   

    From Quanta Magazine: “Scientists Uncover the Universal Geometry of Geology” 

    From Quanta Magazine

    November 19, 2020
    Joshua Sokol

    Plato was right: On average, the world is made out of cubes.

    On a mild autumn day in 2016, the Hungarian mathematician Gábor Domokos arrived on the geophysicist Douglas Jerolmack’s doorstep in Philadelphia. Domokos carried with him his suitcases, a bad cold and a burning secret.

    The two men walked across a gravel lot behind the house, where Jerolmack’s wife ran a taco cart. Their feet crunched over crushed limestone. Domokos pointed down.

    “How many facets do each of these gravel pieces have?” he said. Then he grinned. “What if I told you that the number was always somewhere around six?” Then he asked a bigger question, one that he hoped would worm its way into his colleague’s brain. What if the world is made of cubes?

    At first, Jerolmack objected. Houses can be built out of bricks, but Earth is made of rocks. Obviously, rocks vary. Mica flakes into sheets; crystals crack on sharply defined axes. But from mathematics alone, Domokos argued, any rocks that broke randomly would crack into shapes that have, on average, six faces and eight vertices. Considered together, they would all be shadowy approximations converging on a sort of ideal cube. Domokos had proved it mathematically, he said. Now he needed Jerolmack’s help to show that this is what nature does.

    “It was geometry with an exact prediction that was borne out in the natural world, with essentially no physics involved,” said Jerolmack, a professor at the University of Pennsylvania. “How in the hell does nature let this happen?”

    Over the next few years, the pair chased their geometric vision from microscopic fragments to rock outcrops to planetary surfaces and even to Plato’s Timaeus, suffusing the project with an additional air of mysticism. The foundational Greek philosopher, writing around 360 BCE, had matched his five Platonic solids with five supposed elements: earth, air, fire, water and star stuff. With either foresight or luck or a little of both, Plato paired cubes, the most stackable shape, with earth. “I was like, oh, OK, now we’re getting a little bit metaphysical,” Jerolmack said.

    Gábor Domokos (above) and Douglas Jerolmack (below) had previously collaborated on a project that spanned mathematics and geophysics.
    Credit: Gábor Domokos; Eric Sucar, University of Pennsylvania.

    But they kept finding cuboid averages in nature, plus a few non-cubes that could be explained with the same theories. They ended up with a new mathematical framework: a descriptive language to express how all things fall apart. When their paper was published earlier this year [PNAS], it came titled like a particularly esoteric Harry Potter novel: Plato’s Cube and the Natural Geometry of Fragmentation.

    Several geophysicists contacted by Quanta say the same mathematical framework might also help with problems like understanding erosion from cracked cliff faces, or preventing hazardous rock slides. “That is really, really exciting,” said the University of Edinburgh geomorphologist Mikaël Attal, one of two scientists who reviewed the paper before publication. The other reviewer, the Vanderbilt geophysicist David Furbish, said, “A paper like this makes me think: Can I somehow make use of these ideas?”

    All Possible Breaks

    Long before he came to Philadelphia, Domokos had more innocuous mathematical questions.

    Suppose you fracture something into many pieces. You now have a mosaic: a collection of shapes that could tile back together with no overlaps or gaps, like the floor of an ancient Roman bath. Further suppose those shapes are all convex, with no indentations.

    First Domokos wanted to see if geometry alone could predict what shapes, on average, would make up that kind of mosaic. Then he wanted to be able to describe all other possible collections of shapes you could find.

    In two dimensions, you can try this out without smashing anything. Take a sheet of paper. Make a random slice that divides the page into two pieces. Then make another random slice through each of those two polygons. Repeat this random process a few more times. Then count up and average the number of vertices on all the bits of paper.

    For a geometry student, predicting the answer isn’t too hard. “I bet you a box of beer that I can make you derive that formula within two hours,” Domokos said. The pieces should average four vertices and four sides, averaging to a rectangle.

    You could also consider the same problem in three dimensions. About 50 years ago, the Russian nuclear physicist, dissident and Nobel Peace Prize winner Andrei Dmitrievich Sakharov posed the same problem while chopping heads of cabbage with his wife. How many vertices should the cabbage pieces have, on average? Sakharov passed the problem on to the legendary Soviet mathematician Vladimir Igorevich Arnold and a student. But their efforts to solve it were incomplete and have largely been forgotten.

    The Moeraki Boulders in New Zealand.

    Unaware of this work, Domokos wrote a proof which pointed to cubes as the answer. He wanted to double-check, though, and he suspected that if an answer to the same problem already existed, it would be locked in an inscrutable volume by the German mathematicians Wolfgang Weil and Rolf Schneider, an 80-year-old titan in the field of geometry. Domokos is a professional mathematician, but even he found the text daunting.

    “I found someone who was willing to read that part of the book for me and translate it back into human language,” Domokos said. He found the theorem for any number of dimensions. That confirmed that cubes were indeed the 3D answer.

    Now Domokos had the average shapes produced by splitting a flat surface or a three-dimensional block. But then a larger quest emerged. Domokos realized that he could also develop a mathematical description not just of averages, but of potentiality: Which collections of shapes are even mathematically possible when something falls apart?

    Remember, the shapes produced after something falls apart are a mosaic. They fit together with no overlap or gaps. Those cut-up rectangles, for example, can easily tile together to fill in a mosaic in two dimensions. So can hexagons, in an idealized case of what mathematicians would call a Voronoi pattern. But pentagons? Octagons? They don’t tile.

    Samuel Velasco/Quanta Magazine. Based on graphics from doi.org/10.1073/pnas.2001037117 [above]; martian surface: NASA/JPL-Caltech/University of Arizona.

    In order to properly classify mosaics, Domokos started describing them with two numbers. The first is the average number of vertices per cell. The second is the average number of different cells sharing each vertex. So in a mosaic of hexagonal bath tiles, for example, each cell is a hexagon, which has six vertices. And each vertex is shared by three hexagons.

    In a mosaic, only certain combinations of these two parameters work, forming a narrow swath of shapes that could possibly result from something falling apart.

    Once again, this full swath was fairly easy to find in two dimensions, but much harder in three. Cubes stack together well in 3D, of course, but so do other combinations of shapes, including those that form a 3D version of the Voronoi pattern. To keep the problem feasible, Domokos restricted himself to just mosaics with orderly, convex cells that share the same vertices. Eventually he and the mathematician Zsolt Lángi devised a new conjecture that sketched out the curve of all possible three-dimensional mosaics like this. They published it in Experimental Mathematics, and “then I sent the whole thing to Rolf Schneider, who is of course the god,” Domokos said.

    Samuel Velasco/Quanta Magazine. Based on graphics from doi.org/10.1073/pnas.2001037117.

    “I asked him whether he wanted me to explain how I got this conjecture, but he reassured me that he knew,” Domokos said, laughing. “That meant like a hundred times more than being accepted in any journal.”

    More importantly, Domokos now had a framework. Mathematics offered a way to classify all the patterns that surfaces and blocks could break into. Geometry also predicted that if you fragmented a flat surface randomly, it would break into rough rectangles, and if you did the same in three dimensions, it would produce rough cubes.

    But for any of this to matter to anyone other than a few mathematicians, Domokos had to prove that these same rules manifest themselves in the real world.

    From Geometry to Geology

    By the time Domokos swung through Philadelphia in 2016, he had already made some progress on the real-world problem. He and his colleagues at the Budapest University of Technology and Economics had gathered shards of dolomite eroded from a cliff face on the Hármashatárhegy mountain in Budapest. Over several days, a lab tech with no presuppositions about a universal conspiracy toward cubes painstakingly counted faces and vertices on hundreds of grains. On average? Six faces, eight vertices. Working with János Török, a specialist in computer simulations, and Ferenc Kun, an expert on fragmentation physics, Domokos found that cuboid averages showed up in rock types like gypsum and limestone as well.

    With the math and the early physical evidence, Domokos pitched his idea to a stunned Jerolmack. “Somehow he’s cast a spell, and everything else disappears for a moment,” Jerolmack said.

    Their alliance was a familiar one. Years ago, Domokos had won renown by proving the existence of the Gömböc, a curious three-dimensional shape that swivels into an upright resting position no matter how you push it. To see if Gömböcs existed in the natural world, he had recruited Jerolmack, who helped apply the concept to explain [Nature Communications] the rounding of pebbles on Earth and Mars. Now Domokos was again asking for help in translating lofty mathematical concepts into literal stone.

    The Gömböc is a convex three-dimensional shape of uniform density that has a single stable equilibrium point. Credit: Domokos.

    The two men settled on a new plan. To prove Plato’s cubes actually appear in nature, they needed to show more than just a coincidental echo between geometry and a few handfuls of rock. They needed to consider all rocks and then sketch out a convincing theory of how abstract math could percolate down through messy geophysics and into even messier reality.

    At first, “everything seemed to work,” Jerolmack said. Domokos’ mathematics had predicted that rock shards should average out to cubes. An increasing number of actual rock shards seemed happy to comply. But Jerolmack soon realized that proving the theory would require confronting rule-breaking cases, too.

    After all, the same geometry offered a vocabulary to describe the many other mosaic patterns that could exist in both two and three dimensions. Off the top of his head, Jerolmack could picture a few real-world fractured rocks that didn’t look like rectangles or cubes at all but could still be classified into this larger space.

    Perhaps these examples would sink the cube-world theory entirely. More promisingly, perhaps they would arise only in distinct circumstances and carry separate lessons for geologists. “I said I know that it doesn’t work everywhere, and I need to know why,” Jerolmack said.

    Over the next few years, working on both sides of the Atlantic, Jerolmack and the rest of the team started plotting where real examples of broken rocks fell within Domokos’ framework. When the team investigated surface systems that are essentially two-dimensional — cracking permafrost in Alaska, a dolomite outcrop, and the exposed cracks of a granite block — they found polygons averaging four sides and four vertices, just like the sliced-up sheet of paper. Each of these geological cases seemed to appear where rocks had simply fractured. Here Domokos’ predictions held up.

    Samuel Velasco/Quanta Magazine. Based on graphics from doi.org/10.1073/pnas.2001037117; spot images: Lindy Buckley; Matthew L. Druckenmiller; Hannes Grobe; Courtesy of János Török.

    Another type of fractured slab, meanwhile, proved to be what Jerolmack had hoped for: an exception with its own distinct story to tell. Mud flats that dry, crack, get wet, heal and then crack again have cells averaging six sides and six vertices, following the roughly hexagonal Voronoi pattern. Rock made from cooling lava, which solidifies downward from the surface, can take on a similar appearance.

    Tellingly, these systems tended to form under a different type of stress — when forces pulled outward on a rock instead of pushing it in. The geometry revealed the geology. And Jerolmack and Domokos thought this Voronoi pattern, even if it was relatively rare, might also occur on scales far larger than they had previously considered.

    A Voronoi diagram separates a plane into individual regions, or cells, so that each cell consists of all points closest to a starting “seed” point. Credit: Fred Scharmen.

    Counting the Crust

    Midway through the project, the team met in Budapest and spent three whirlwind days sprinting to incorporate more natural examples. Soon Jerolmack pulled up a new pattern on his computer: the mosaic of how Earth’s tectonic plates fit together. Plates are confined to the lithosphere, a nearly two-dimensional skin on the surface of the planet. The pattern looked familiar, and Jerolmack called the others over. “We were like, oh wow,” he said.

    By eye, the plates looked as if they hewed to the Voronoi pattern, not the rectangular one. Then the team counted. In a perfect Voronoi mosaic of hexagons in a flat plane, each cell would have six vertices. The actual tectonic plates averaged 5.77 vertices.

    For a geophysicist, that was close enough to celebrate. For a mathematician, not so much. “Doug was getting into a good mood. He was working like hell,” Domokos said. “I was getting in a depressed mood for the next day, because I was just thinking about the gap.”

    Domokos went home for the night, the difference still gnawing at him. He wrote down the numbers again. And then it hit him. A mosaic of hexagons can tile a plane. But Earth isn’t a flat plane, at least outside certain corners of YouTube. Think of a soccer ball, covered in both hexagons and pentagons. Domokos crunched the numbers for the surface of a sphere and found that on a globe, Voronoi mosaic cells should average 5.77 vertices.

    This insight might help researchers answer a major open question in geophysics: How did Earth’s tectonic plates form? One idea holds that plates are just a byproduct of burbling convection cells deep in the mantle. But an opposing camp holds that Earth’s crust is a separate system — one that expanded, grew brittle and cracked open. The observed Voronoi pattern of plates, reminiscent of much smaller mud flats, might support the second argument, Jerolmack said. “That’s also what made me realize how important that paper was,” Attal said. “It’s really phenomenal.”

    A Revealing Break

    In three dimensions, meanwhile, exceptions to the cuboid rule were rare enough. And they too could be produced by simulating unusual, outward-pulling forces. One distinctively non-cubic rock formation lies on the coast of Northern Ireland, where waves lap against tens of thousands of basalt columns. In Irish this is Clochán na bhFomhórach, the steppingstones of a race of supernatural beings; the English name is the Giant’s Causeway.

    Giant’s Causeway and Causeway Coast © Stefano Berti.

    Crucially, those columns and other similar volcanic rock formations are six-sided. But Török’s simulations produced Giant’s Causeway-like mosaics as three-dimensional structures that had simply grown up from a two-dimensional Voronoi base, itself produced when volcanic rock cooled.

    The Giant’s Causeway in Northern Ireland. Credit: Tyler Donaghy.

    Zooming out, the team argues, you could classify most real fractured-rock mosaics using just Platonic rectangles, 2D Voronoi patterns, and then — overwhelmingly — Platonic cubes in three dimensions. Each of these patterns could tell a geological story. And yes, with the appropriate caveats, you really could say the world is made of cubes.

    “They did their due diligence in vetting their modeled forms against reality,” said Martha-Cary Eppes, an earth scientist at the University of North Carolina, Charlotte. “My initial skepticism was allayed.”

    “The math is telling us that when we begin to fracture rocks, however we do it, whether we do it randomly or deterministically, there is only a certain set of possibilities,” said Furbish. “How clever is that?”

    Specifically, perhaps you could take a real fractured field site, count up things like vertices and faces, and then be able to infer something about the geological circumstances responsible.

    “We have places where we have data we can think about in this way,” said Roman DiBiase, a geomorphologist at Pennsylvania State University. “That would be a really cool outcome, if you can discern things that are more subtle than the Giant’s Causeway, and hitting a rock with a hammer and seeing what the shards look like.”

    As for Jerolmack, after first feeling uncomfortable over a possibly coincidental connection to Plato, he has come to embrace it. After all, the Greek philosopher proposed that ideal geometric forms are central to understanding the universe but always out of sight, visible only as distorted shadows.

    “This is literally the most direct example we can think of. The statistical average of all these observations is the cube,” Jerolmack said.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Formerly known as Simons Science News, Quanta Magazine is an editorially independent online publication launched by the Simons Foundation to enhance public understanding of science. Why Quanta? Albert Einstein called photons “quanta of light.” Our goal is to “illuminate science.” At Quanta Magazine, scientific accuracy is every bit as important as telling a good story. All of our articles are meticulously researched, reported, edited, copy-edited and fact-checked.

  • richardmitnick 8:17 am on October 5, 2020 Permalink | Reply
    Tags: "Stanford model shows how fluids unlock faults to unleash earthquake swarms", , , , , Geophysics, ,   

    From Stanford University: “Stanford model shows how fluids unlock faults to unleash earthquake swarms” 

    Stanford University Name
    From Stanford University

    September 24, 2020 [Just now in social media.]

    Josie Garthwaite
    School of Earth, Energy & Environmental Sciences:
    (650) 497-0947

    A new fault simulator maps out how interactions between pressure, friction and fluids rising through a fault zone can lead to slow-motion quakes and seismic swarms.

    New modeling shows for the first time that as pulses of high-pressure fluids travel upward along a fault, they can create earthquake swarms. Credit: iStock.

    Earthquakes can be abrupt bursts of home-crumbling, ground-buckling energy when slices of the planet’s crust long held in place by friction suddenly slip and lurch.

    “We typically think of the plates on either side of a fault moving, deforming, building up stresses and then: Boom, an earthquake happens,” said Stanford University geophysicist Eric Dunham.

    But deeper down, these blocks of rock can slide steadily past one another, creeping along cracks in Earth’s crust at about the rate that your fingernails grow.

    A boundary exists between the lower, creeping part of the fault, and the upper portion that may stand locked for centuries at a stretch. For decades, scientists have puzzled over what controls this boundary, its movements and its relationship with big earthquakes. Chief among the unknowns is how fluid and pressure migrate along faults, and how that causes faults to slip.

    A new physics-based fault simulator developed by Dunham and colleagues provides some answers. The model shows how fluids ascending by fits and starts gradually weaken the fault. In the decades leading up to big earthquakes, they seem to propel the boundary, or locking depth, a mile or two upward.

    Migrating swarms

    The research, published Sept. 24 in Nature Communications, also suggests that as pulses of high-pressure fluids draw closer to the surface, they can trigger earthquake swarms – strings of quakes clustered in a local area, usually over a week or so. Shaking from these seismic swarms is often too subtle for people to notice, but not always: A swarm near the southern end of the San Andreas Fault in California in August 2020, for example, produced a magnitude-4.6 quake strong enough to rattle surrounding cities.

    Each of the earthquakes in a swarm has its own aftershock sequence, as opposed to one large mainshock followed by many aftershocks. “An earthquake swarm often involves migration of these events along a fault in some direction, horizontally or vertically,” explained Dunham, senior author of the paper and an associate professor of geophysics at Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth).

    The simulator maps out how this migration works. Whereas much of the advanced earthquake modeling of the last 20 years has focused on the role of friction in unlocking faults, the new work accounts for interactions between fluid and pressure in the fault zone using a simplified, two-dimensional model of a fault that cuts vertically through Earth’s entire crust, similar to the San Andreas Fault in California.

    “Through computational modeling, we were able to tease out some of the root causes for fault behavior,” said lead author Weiqiang Zhu, a graduate student in geophysics at Stanford. “We found the ebb and flow of pressure around a fault may play an even bigger role than friction in dictating its strength.”

    Underground valves

    Faults in Earth’s crust are always saturated with fluids – mostly water, but water in a state that blurs distinctions between liquid and gas. Some of these fluids originate in Earth’s belly and migrate upwards; some come from above when rainfall seeps in or energy developers inject fluids as part of oil, gas or geothermal projects. “Increases in the pressure of that fluid can push out on the walls of the fault, and make it easier for the fault to slide,” Dunham said. “Or, if the pressure decreases, that creates a suction that pulls the walls together and inhibits sliding.”

    For decades, studies of rocks unearthed from fault zones have revealed telltale cracks, mineral-filled veins and other signs that pressure can fluctuate wildly during and between big quakes, leading geologists to theorize that water and other fluids play an important role in triggering earthquakes and influencing when the biggest temblors strike. “The rocks themselves are telling us this is an important process,” Dunham said.

    More recently, scientists have documented that fluid injection related to energy operations can lead to earthquake swarms. Seismologists have linked oil and gas wastewater disposal wells, for example, to a dramatic increase in earthquakes in parts of Oklahoma starting around 2009. And they’ve found that earthquake swarms migrate along faults faster or slower in different environments, whether it’s underneath a volcano, around a geothermal operation or within oil and gas reservoirs, possibly because of wide variation in fluid production rates, Dunham explained. But modeling had yet to untangle the web of physical mechanisms behind the observed patterns.

    Dunham and Zhu’s work builds on a concept of faults as valves, which geologists first put forth in the 1990s. “The idea is that fluids ascend along faults intermittently, even if those fluids are being released or injected at a steady, constant rate,” Dunham explained. In the decades to thousands of years between large earthquakes, mineral deposition and other chemical processes seal the fault zone.

    With the fault valve closed, fluid accumulates and pressure builds, weakening the fault and forcing it to slip. Sometimes this movement is too slight to generate ground shaking, but it’s enough to fracture the rock and open the valve, allowing fluids to resume their ascent.

    The new modeling shows for the first time that as these pulses travel upward along the fault, they can create earthquake swarms. “The concept of a fault valve, and intermittent release of fluids, is an old idea,” Dunham said. “But the occurrence of earthquake swarms in our simulations of fault valving was completely unexpected.”

    Predictions, and their limits

    The model makes quantitative predictions about how quickly a pulse of high-pressure fluids migrates along the fault, opens up pores, causes the fault to slip and triggers certain phenomena: changes in the locking depth, in some cases, and imperceptibly slow fault movements or clusters of small earthquakes in others. Those predictions can then be tested against the actual seismicity along a fault – in other words, when and where small or slow-motion earthquakes end up occurring.

    For instance, one set of simulations, in which the fault was set to seal up and halt fluid migration within three or four months, predicted a little more than an inch of slip along the fault right around the locking depth over the course of a year, with the cycle repeating every few years. This particular simulation closely matches patterns of so-called slow-slip events observed in New Zealand and Japan – a sign that the underlying processes and mathematical relationships built into the algorithm are on target. Meanwhile, simulations with sealing dragged out over years caused the locking depth to rise as pressure pulses climbed upward.

    Changes in the locking depth can be estimated from GPS measurements of the deformation of Earth’s surface. Yet the technology is not an earthquake predictor, Dunham said. That would require more complete knowledge of the processes that influence fault slip, as well as information about the particular fault’s geometry, stress, rock composition and fluid pressure, he explained, “at a level of detail that is simply impossible, given that most of the action is happening many miles underground.”

    Rather, the model offers a way to understand processes: how changes in fluid pressure cause faults to slip; how sliding and slip of a fault breaks up the rock and makes it more permeable; and how that increased porosity allows fluids to flow more easily.

    In the future, this understanding could help to inform assessments of risk related to injecting fluids into the Earth. According to Dunham, “The lessons that we learn about how fluid flow couples with frictional sliding are applicable to naturally occurring earthquakes as well as induced earthquakes that are happening in oil and gas reservoirs.”

    See the full article here .

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    Stanford University campus. No image credit

    Stanford University

    Leland and Jane Stanford founded the University to “promote the public welfare by exercising an influence on behalf of humanity and civilization.” Stanford opened its doors in 1891, and more than a century later, it remains dedicated to finding solutions to the great challenges of the day and to preparing our students for leadership in today’s complex world. Stanford, is an American private research university located in Stanford, California on an 8,180-acre (3,310 ha) campus near Palo Alto. Since 1952, more than 54 Stanford faculty, staff, and alumni have won the Nobel Prize, including 19 current faculty members

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  • richardmitnick 7:39 am on September 12, 2020 Permalink | Reply
    Tags: "High-fidelity record of Earth’s climate history puts current changes in context", , , , For the first time climate scientists have compiled a continuous high-fidelity record of variations in Earth’s climate extending 66 million years into the past., Geophysics, Greenhouse gas emissions and other human activities are now driving the planet toward the Warmhouse and Hothouse climate states not seen since the Eocene epoch., The climate shows rhythmic variations corresponding to changes in Earth’s orbit around the sun., The new climate record provides a valuable framework for many areas of research., The record reveals four distinctive climate states which the researchers dubbed Hothouse; Warmhouse; Coolhouse; and Icehouse.,   

    From UC Santa Cruz: “High-fidelity record of Earth’s climate history puts current changes in context” 

    From UC Santa Cruz

    September 10, 2020
    Tim Stephens

    A continuous record of the past 66 million years shows natural climate variability due to changes in Earth’s orbit around the sun is much smaller than projected future warming due to greenhouse gas emissions.


    For the first time, climate scientists have compiled a continuous, high-fidelity record of variations in Earth’s climate extending 66 million years into the past. The record reveals four distinctive climate states, which the researchers dubbed Hothouse, Warmhouse, Coolhouse, and Icehouse.

    These major climate states persisted for millions and sometimes tens of millions of years, and within each one the climate shows rhythmic variations corresponding to changes in Earth’s orbit around the sun. But each climate state has a distinctive response to orbital variations, which drive relatively small changes in global temperatures compared with the dramatic shifts between different climate states.

    The new findings, published September 10 in Science, are the result of decades of work and a large international collaboration. The challenge was to determine past climate variations on a time scale fine enough to see the variability attributable to orbital variations (in the eccentricity of Earth’s orbit around the sun and the precession and tilt of its rotational axis).

    “We’ve known for a long time that the glacial-interglacial cycles are paced by changes in Earth’s orbit, which alter the amount of solar energy reaching Earth’s surface, and astronomers have been computing these orbital variations back in time,” explained coauthor James Zachos, distinguished professor of Earth and planetary sciences and Ida Benson Lynn Professor of Ocean Health at UC Santa Cruz.

    “As we reconstructed past climates, we could see long-term coarse changes quite well. We also knew there should be finer-scale rhythmic variability due to orbital variations, but for a long time it was considered impossible to recover that signal,” Zachos said. “Now that we have succeeded in capturing the natural climate variability, we can see that the projected anthropogenic warming will be much greater than that.”


    For the past 3 million years, Earth’s climate has been in an Icehouse state characterized by alternating glacial and interglacial periods. Modern humans evolved during this time, but greenhouse gas emissions and other human activities are now driving the planet toward the Warmhouse and Hothouse climate states not seen since the Eocene epoch, which ended about 34 million years ago. During the early Eocene, there were no polar ice caps, and average global temperatures were 9 to 14 degrees Celsius higher than today.

    “The IPCC projections for 2300 in the ‘business-as-usual’ scenario will potentially bring global temperature to a level the planet has not seen in 50 million years,” Zachos said.

    Critical to compiling the new climate record was getting high-quality sediment cores from deep ocean basins through the international Ocean Drilling Program (ODP, later the Integrated Ocean Drilling Program, IODP, succeeded in 2013 by the International Ocean Discovery Program). Signatures of past climates are recorded in the shells of microscopic plankton (called foraminifera) preserved in the seafloor sediments. After analyzing the sediment cores, researchers then had to develop an “astrochronology” by matching the climate variations recorded in sediment layers with variations in Earth’s orbit (known as Milankovitch cycles).

    “The community figured out how to extend this strategy to older time intervals in the mid-1990s,” said Zachos, who led a study published in 2001 in Science that showed the climate response to orbital variations for a 5-million-year period covering the transition from the Oligocene epoch to the Miocene, about 25 million years ago.

    “That changed everything, because if we could do that, we knew we could go all the way back to maybe 66 million years ago and put these transient events and major transitions in Earth’s climate in the context of orbital-scale variations,” he said.

    Sediment cores

    Zachos has collaborated for years with lead author Thomas Westerhold at the University of Bremen Center for Marine Environmental Sciences (MARUM) in Germany, which houses a vast repository of sediment cores. The Bremen lab along with Zachos’s group at UCSC generated much of the new data for the older part of the record.

    Westerhold oversaw a critical step, splicing together overlapping segments of the climate record obtained from sediment cores from different parts of the world. “It’s a tedious process to assemble this long megasplice of climate records, and we also wanted to replicate the records with separate sediment cores to verify the signals, so this was a big effort of the international community working together,” Zachos said.

    Now that they have compiled a continuous, astronomically dated climate record of the past 66 million years, the researchers can see that the climate’s response to orbital variations depends on factors such as greenhouse gas levels and the extent of polar ice sheets.

    “In an extreme greenhouse world with no ice, there won’t be any feedbacks involving the ice sheets, and that changes the dynamics of the climate,” Zachos explained.

    Greenhouse gas levels

    Most of the major climate transitions in the past 66 million years have been associated with changes in greenhouse gas levels. Zachos has done extensive research on the Paleocene-Eocene Thermal Maximum (PETM), for example, showing that this episode of rapid global warming, which drove the climate into a Hothouse state, was associated with a massive release of carbon into the atmosphere. Similarly, in the late Eocene, as atmospheric carbon dioxide levels were dropping, ice sheets began to form in Antarctica and the climate transitioned to a Coolhouse state.

    “The climate can become unstable when it’s nearing one of these transitions, and we see more deterministic responses to orbital forcing, so that’s something we would like to better understand,” Zachos said.

    The new climate record provides a valuable framework for many areas of research, he added. It is not only useful for testing climate models, but also for geophysicists studying different aspects of Earth dynamics and paleontologists studying how changing environments drive the evolution of species.

    “It’s a significant advance in Earth science, and a major legacy of the international Ocean Drilling Program,” Zachos said.

    Coauthors Steven Bohaty, now at the University of Southampton, and Kate Littler, now at the University of Exeter, both worked with Zachos at UC Santa Cruz. The paper’s coauthors also include researchers at more than a dozen institutions around the world. This work was funded by the German Research Foundation (DFG), Natural Environmental Research Council (NERC), European Union’s Horizon 2020 program, National Science Foundation of China, Netherlands Earth System Science Centre, and the U.S. National Science Foundation.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    UCSC Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft).

    UC Observatories Lick Autmated Planet Finder, fully robotic 2.4-meter optical telescope at Lick Observatory, situated on the summit of Mount Hamilton, east of San Jose, California, USA.

    The UCO Lick C. Donald Shane telescope is a 120-inch (3.0-meter) reflecting telescope located at the Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft).

    UC Santa Cruz campus

    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

    UCSC is the home base for the Lick Observatory.

    Lick Observatory’s 36-inch Great Great Refractor telescope housed in the South (large) Dome of main building.

    Search for extraterrestrial intelligence expands at Lick Observatory
    New instrument scans the sky for pulses of infrared light
    March 23, 2015
    By Hilary Lebow
    The NIROSETI instrument saw first light on the Nickel 1-meter Telescope at Lick Observatory on March 15, 2015. (Photo by Laurie Hatch) UCSC Lick Nickel telescope

    Astronomers are expanding the search for extraterrestrial intelligence into a new realm with detectors tuned to infrared light at UC’s Lick Observatory. A new instrument, called NIROSETI, will soon scour the sky for messages from other worlds.

    “Infrared light would be an excellent means of interstellar communication,” said Shelley Wright, an assistant professor of physics at UC San Diego who led the development of the new instrument while at the University of Toronto’s Dunlap Institute for Astronomy & Astrophysics.

    Wright worked on an earlier SETI project at Lick Observatory as a UC Santa Cruz undergraduate, when she built an optical instrument designed by UC Berkeley researchers. The infrared project takes advantage of new technology not available for that first optical search.

    Infrared light would be a good way for extraterrestrials to get our attention here on Earth, since pulses from a powerful infrared laser could outshine a star, if only for a billionth of a second. Interstellar gas and dust is almost transparent to near infrared, so these signals can be seen from great distances. It also takes less energy to send information using infrared signals than with visible light.

    Frank Drake, professor emeritus of astronomy and astrophysics at UC Santa Cruz and director emeritus of the SETI Institute, said there are several additional advantages to a search in the infrared realm.

    “The signals are so strong that we only need a small telescope to receive them. Smaller telescopes can offer more observational time, and that is good because we need to search many stars for a chance of success,” said Drake.

    The only downside is that extraterrestrials would need to be transmitting their signals in our direction, Drake said, though he sees this as a positive side to that limitation. “If we get a signal from someone who’s aiming for us, it could mean there’s altruism in the universe. I like that idea. If they want to be friendly, that’s who we will find.”

    Scientists have searched the skies for radio signals for more than 50 years and expanded their search into the optical realm more than a decade ago. The idea of searching in the infrared is not a new one, but instruments capable of capturing pulses of infrared light only recently became available.

    “We had to wait,” Wright said. “I spent eight years waiting and watching as new technology emerged.”

    Now that technology has caught up, the search will extend to stars thousands of light years away, rather than just hundreds. NIROSETI, or Near-Infrared Optical Search for Extraterrestrial Intelligence, could also uncover new information about the physical universe.

    “This is the first time Earthlings have looked at the universe at infrared wavelengths with nanosecond time scales,” said Dan Werthimer, UC Berkeley SETI Project Director. “The instrument could discover new astrophysical phenomena, or perhaps answer the question of whether we are alone.”

    NIROSETI will also gather more information than previous optical detectors by recording levels of light over time so that patterns can be analyzed for potential signs of other civilizations.

    “Searching for intelligent life in the universe is both thrilling and somewhat unorthodox,” said Claire Max, director of UC Observatories and professor of astronomy and astrophysics at UC Santa Cruz. “Lick Observatory has already been the site of several previous SETI searches, so this is a very exciting addition to the current research taking place.”

    NIROSETI will be fully operational by early summer and will scan the skies several times a week on the Nickel 1-meter telescope at Lick Observatory, located on Mt. Hamilton east of San Jose.

    The NIROSETI team also includes Geoffrey Marcy and Andrew Siemion from UC Berkeley; Patrick Dorval, a Dunlap undergraduate, and Elliot Meyer, a Dunlap graduate student; and Richard Treffers of Starman Systems. Funding for the project comes from the generous support of Bill and Susan Bloomfield.

  • richardmitnick 5:17 pm on August 24, 2020 Permalink | Reply
    Tags: , , At least twice in Earth’s history nearly the entire planet was encased in a sheet of snow and ice., , Geophysics, , The findings may also apply to the search for life on other planets.   

    From MIT News: “Study: A plunge in incoming sunlight may have triggered ‘Snowball Earths'” 

    MIT News

    From MIT News

    July 29, 2020
    Jennifer Chu

    The trigger for “Snowball Earth” global ice ages may have been drops in incoming sunlight that happened quickly, in geological terms, according to an MIT study. Credits: Image: Wikimedia, Oleg Kuznetsov

    At least twice in Earth’s history, nearly the entire planet was encased in a sheet of snow and ice. These dramatic “Snowball Earth” events occurred in quick succession, somewhere around 700 million years ago, and evidence suggests that the consecutive global ice ages set the stage for the subsequent explosion of complex, multicellular life on Earth.

    Scientists have considered multiple scenarios for what may have tipped the planet into each ice age. While no single driving process has been identified, it’s assumed that whatever triggered the temporary freeze-overs must have done so in a way that pushed the planet past a critical threshold, such as reducing incoming sunlight or atmospheric carbon dioxide to levels low enough to set off a global expansion of ice.

    But MIT scientists now say that Snowball Earths were likely the product of “rate-induced glaciations.” That is, they found the Earth can be tipped into a global ice age when the level of solar radiation it receives changes quickly over a geologically short period of time. The amount of solar radiation doesn’t have to drop to a particular threshold point; as long as the decrease in incoming sunlight occurs faster than a critical rate, a temporary glaciation, or Snowball Earth, will follow.

    These findings, published today in the Proceedings of the Royal Society A, suggest that whatever triggered the Earth’s ice ages most likely involved processes that quickly reduced the amount of solar radiation coming to the surface, such as widespread volcanic eruptions or biologically induced cloud formation that could have significantly blocked out the sun’s rays.

    The findings may also apply to the search for life on other planets. Researchers have been keen on finding exoplanets within the habitable zone — a distance from their star that would be within a temperature range that could support life. The new study suggests that these planets, like Earth, could also ice over temporarily if their climate changes abruptly. Even if they lie within a habitable zone, Earth-like planets may be more susceptible to global ice ages than previously thought.

    “You could have a planet that stays well within the classical habitable zone, but if incoming sunlight changes too fast, you could get a Snowball Earth,” says lead author Constantin Arnscheidt, a graduate student in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). “What this highlights is the notion that there’s so much more nuance in the concept of habitability.”

    Arnscheidt has co-authored the paper with Daniel Rothman, EAPS professor of geophysics, and co-founder and co-director of the Lorenz Center.

    A runaway snowball

    Regardless of the particular processes that triggered past glaciations, scientists generally agree that Snowball Earths arose from a “runaway” effect involving an ice-albedo feedback: As incoming sunlight is reduced, ice expands from the poles to the equator. As more ice covers the globe, the planet becomes more reflective, or higher in albedo, which further cools the surface for more ice to expand. Eventually, if the ice reaches a certain extent, this becomes a runaway process, resulting in a global glaciation.

    Global ice ages on Earth are temporary in nature, due to the planet’s carbon cycle. When the planet is not covered in ice, levels of carbon dioxide in the atmosphere are somewhat controlled by the weathering of rocks and minerals. When the planet is covered in ice, weathering is vastly reduced, so that carbon dioxide builds up in the atmosphere, creating a greenhouse effect that eventually thaws the planet out of its ice age.

    Scientists generally agree that the formation of Snowball Earths has something to do with the balance between incoming sunlight, the ice-albedo feedback, and the global carbon cycle.

    “There are lots of ideas for what caused these global glaciations, but they all really boil down to some implicit modification of solar radiation coming in,” Arnscheidt says. “But generally it’s been studied in the context of crossing a threshold.”

    He and Rothman had previously studied other periods in Earth’s history where the speed, or rate at which certain changes in climate occurred had a role in triggering events, such as past mass extinctions.

    “In the course of this exercise, we realized there was an immediate way to make a serious point by applying such ideas of rate-induced tipping, to Snowball Earth and habitability,” Rothman says.

    “Be wary of speed”

    The researchers developed a simple mathematical model of the Earth’s climate system that includes equations to represent relations between incoming and outgoing solar radiation, the surface temperature of the Earth, the concentration of carbon dioxide in the atmosphere, and the effects of weathering in taking up and storing atmospheric carbon dioxide. The researchers were able to tune each of these parameters to observe which conditions generated a Snowball Earth.

    Ultimately, they found that a planet was more likely to freeze over if incoming solar radiation decreased quickly, at a rate that was faster than a critical rate, rather than to a critical threshold, or particular level of sunlight. There is some uncertainty in exactly what that critical rate would be, as the model is a simplified representation of the Earth’s climate. Nevertheless, Arnscheidt estimates that the Earth would have to experience about a 2 percent drop in incoming sunlight over a period of about 10,000 years to tip into a global ice age.

    “It’s reasonable to assume past glaciations were induced by geologically quick changes to solar radiation,” Arnscheidt says.

    The particular mechanisms that may have quickly darkened the skies over tens of thousands of years is still up for debate. One possibility is that widespread volcanoes may have spewed aerosols into the atmosphere, blocking incoming sunlight around the world. Another is that primitive algae may have evolved mechanisms that facilitated the formation of light-reflecting clouds. The results from this new study suggest scientists may consider processes such as these, that quickly reduce incoming solar radiation, as more likely triggers for Earth’s ice ages.

    “Even though humanity will not trigger a snowball glaciation on our current climate trajectory, the existence of such a ‘rate-induced tipping point’ at the global scale may still remain a cause for concern,” Arnscheidt points out. “For example, it teaches us that we should be wary of the speed at which we are modifying Earth’s climate, not just the magnitude of the change. There could be other such rate-induced tipping points that might be triggered by anthropogenic warming. Identifying these and constraining their critical rates is a worthwhile goal for further research.”

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    MIT Seal

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

    MIT Campus

  • richardmitnick 9:20 am on July 4, 2020 Permalink | Reply
    Tags: "Geologists Identify Deep-Earth Structures That May Signal Hidden Metal Lodes", , , , , , Geophysics, The mining of metals needed to create a vast infrastructure for renewable power generation; storage; transmission and usage., The new study started in 2016 in Australia where much of the world’s lead zinc and copper is mined., The scientists’ map shows such zones looping through all the continents., The study’s authors found that the richest Australian mines lay neatly along the line where thick old lithosphere grades out to 170 kilometers as it approaches the coast.   

    From Columbia University – State of the Planet: “Geologists Identify Deep-Earth Structures That May Signal Hidden Metal Lodes” 

    Columbia U bloc

    From Columbia University – State of the Planet

    June 30, 2020
    Kevin Krajick

    Finding New Giant Copper, Lead, Zinc Deposits Will Fuel Green Infrastructure.

    If the world is to maintain a sustainable economy and fend off the worst effects of climate change, at least one industry will soon have to ramp up dramatically: the mining of metals needed to create a vast infrastructure for renewable power generation, storage, transmission and usage. The problem is, demand for such metals is likely to far outstrip currently both known deposits and the existing technology used to find more ore bodies.

    Now, in a new study, scientists have discovered previously unrecognized structural lines 100 miles or more down in the earth that appear to signal the locations of giant deposits of copper, lead, zinc and other vital metals lying close enough to the surface to be mined, but too far down to be found using current exploration methods. The discovery could greatly narrow down search areas, and reduce the footprint of future mines, the authors say. The study appears this week in the journal Nature Geoscience.

    “We can’t get away from these metals—they’re in everything, and we’re not going to recycle everything that was ever made,” said lead author Mark Hoggard, a postdoctoral researcher at Harvard University and Columbia University’s Lamont-Doherty Earth Observatory. “There’s a real need for alternative sources.”

    A new study shows that giant ore deposits are tightly distributed above where rigid rocks that comprise the nuclei of ancient continents begin to thin, far below the surface (white areas). Redder areas indicate the thinnest rocks beyond the boundary; bluer ones, the thickest. Circles, triangles and squares show known large sediment-hosted deposits of different metals. (Adapted from Hoggard et al., Nature Geoscience, 2020)

    The study found that 85 percent of all known base-metal deposits hosted in sediments—and 100 percent of all “giant” deposits (those holding more than 10 million tons of metal)—lie above deeply buried lines girdling the planet that mark the edges of ancient continents. Specifically, the deposits lie along boundaries where the earth’s lithosphere—the rigid outermost cladding of the planet, comprising the crust and upper mantle—thins out to about 170 kilometers below the surface.

    Up to now, all such deposits have been found pretty much at the surface, and their locations have seemed to be somewhat random. Most discoveries have been made basically by geologists combing the ground and whacking at rocks with hammers. Geophysical exploration methods using gravity and other parameters to find buried ore bodies have entered in recent decades, but the results have been underwhelming. The new study presents geologists with a new, high-tech treasure map telling them where to look.

    Due to the demands of modern technology and the growth of populations and economies, the need for base metals in the next 25 years is projected to outpace all the base metals so far mined in human history. Copper is used in basically all electronics wiring, from cell phones to generators; lead for photovoltaic cells, high-voltage cables, batteries and super capacitors; and zinc for batteries, as well as fertilizers in regions where it is a limiting factor in soils, including much of China and India. Many base-metal mines also yield rarer needed elements, including cobalt, iridium and molybdenum. One recent study suggests that in order to develop a sustainable global economy, between 2015 and 2050 electric passenger vehicles must increase from 1.2 million to 1 billion; battery capacity from 0.5 gigawatt hours to 12,000; and photovoltaic capacity from 223 gigawatts to more than 7,000.

    The new study started in 2016 in Australia, where much of the world’s lead, zinc and copper is mined. The government funded work to see whether mines in the northern part of the continent had anything in common. It built on the fact that in recent years, scientists around the world have been using seismic waves to map the highly variable depth of the lithosphere, which ranges down to 300 kilometers in the nuclei of the most ancient, undisturbed continental masses, and tapers to near zero under the younger rocks of the ocean floors. As continents have shifted, collided and rifted over many eons, their subsurfaces have developed scar-like lithospheric irregularities, many of which have now been mapped.

    The study’s authors found that the richest Australian mines lay neatly along the line where thick, old lithosphere grades out to 170 kilometers as it approaches the coast. They then expanded their investigation to some 2,100 sediment-hosted mines across the world, and found an identical pattern. Some of the 170-kilometer boundaries lie near current coastlines, but many are nestled deep within the continents, having formed at various points in the distant past when the continents had different shapes. Some are up to 2 billion years old.

    The scientists’ map shows such zones looping through all the continents, including areas in western Canada; the coasts of Australia, Greenland and Antarctica; the western, southeastern and Great Lakes regions of the United States; and much of the Amazon, northwest and southern Africa, northern India and central Asia. While some of the identified areas already host enormous mines, others are complete blanks on the mining map.

    The authors believe that the metal deposits formed when thick continental rocks stretched out and sagged to form a depression, like a wad of gum pulled apart. This thinned the lithosphere and allowed seawater to flood in. Over long periods, these watery low spots got filled in with metal-bearing sediments from adjoining, higher-elevation rocks. Salty water then circulated downward until reaching depths where chemical and temperature conditions were just right for metals picked up by the water in deep parts of the basin to precipitate out to form giant deposits, anywhere from 100 meters to 10 kilometers below the then-surface. The key ingredient was the depth of the lithosphere. Where it is thickest, little heat from the hot lower mantle rises to potential near-surface ore-forming zones, and where it is thinnest, a lot of heat gets through. The 170-kilometer boundary seems to be Goldilocks zone for creating just the right temperature conditions, as long as the right chemistry also is present.

    “It really just hits the sweet spot,” said Hoggard. “These deposits contain lots of metal bound up in high-grade ores, so once you find something like this, you only have to dig one hole.” Most current base-metal mines are sprawling, destructive open-pit operations. But in many cases, deposits starting as far down as a kilometer could probably be mined economically, and these would “almost certainly be taken out via much less disruptive shafts,” said Hoggard.

    The study promises to open exploration in so far poorly explored areas, including parts of Australia, central Asia and western Africa. Based on a preliminary report of the new study that the authors presented at an academic conference last year, a few companies appear to have already claimed ground in Australia and North America. But the mining industry is notoriously secretive, so it is not clear yet how widespread such activity might be.

    “This is a truly profound finding and is the first time anyone has suggested that mineral deposits formed in sedimentary basins … at depths of only kilometers in the crust were being controlled by forces at depths of hundreds of kilometers at the base of the lithosphere,” said a report in Mining Journal reviewing the preliminary presentation last year.

    The study’s other authors are Karol Czarnota of Geoscience Australia, who led the initial Australian mapping project; Fred Richards of Harvard University and Imperial College London; David Huston of Geoscience Australia; and A. Lynton Jaques and Sia Ghelichkhan of Australian National University.

    Hoggard has put the study into a global context on his website.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

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    Columbia University was founded in 1754 as King’s College by royal charter of King George II of England. It is the oldest institution of higher learning in the state of New York and the fifth oldest in the United States.

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