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Tag: geology

  • Expert Available on Earthquakes and Damage in Turkey and Syria

    Expert Available on Earthquakes and Damage in Turkey and Syria

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    Newswise — Rensselaer Polytechnic Institute’s Mourad Zeghal, professor of civil and environmental engineering, is available for comment on the earthquakes in Turkey and Syria. He can speak on ground motion during earthquakes, soil-structure interaction, and damage to buildings and infrastructure.

    Zeghal’s research interests include geotechnical earthquake engineering, seismic response monitoring, information technology applications in geomechanics, and computational soil micro-mechanics.

    Failure of geosystems due to natural or man-made hazards such as hurricanes, floods, earthquakes, or terrorist attacks may have monumental repercussions, sometimes with dramatic and unanticipated consequences on human life and the country’s economy. Zeghal’s research focuses on three areas that are central to the national effort to reduce the impact of these hazards: (1) monitoring and testing of  soil systems, (2) multiscale modeling of soil-systems and model validation, and (3) development of improved optimal analysis and design tools.

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    Rensselaer Polytechnic Institute (RPI)

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  • Scientists detect molten rock layer hidden under earth’s tectonic plates

    Scientists detect molten rock layer hidden under earth’s tectonic plates

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    Newswise — Scientists have discovered a new layer of partly molten rock under the Earth’s crust that might help settle a long-standing debate about how tectonic plates move. 

    Researchers had previously identified patches of melt at a similar depth. But a new study led by The University of Texas at Austin revealed for the first time the layer’s global extent and its part in plate tectonics.

    The research was published Feb. 6, 2023, in the journal Nature Geoscience. 

    The molten layer is located about 100 miles from the surface and is part of the asthenosphere, which sits under the Earth’s tectonic plates in the upper mantle. The asthenosphere is important for plate tectonics because it forms a relatively soft boundary that lets tectonic plates move through the mantle. 

    The reasons why it is soft, however, are not well understood. Scientists previously thought that molten rocks might be a factor. But this study shows that melt, in fact, does not appear to notably influence the flow of mantle rocks.   

    “When we think about something melting, we intuitively think that the melt must play a big role in the material’s viscosity,” said Junlin Hua, a postdoctoral fellow at UT’s Jackson School of Geosciences who led the research. “But what we found is that even where the melt fraction is quite high, its effect on mantle flow is very minor.”

    According to the research, which Hua began as a graduate student at Brown University, the convection of heat and rock in the mantle are the prevailing influence on the motion of the plates. Although the Earth’s interior is largely solid, over long periods of time, rocks can shift and flow like honey. 

    Showing that the melt layer has no influence on plate tectonics means one less tricky variable for computer models of the Earth, said coauthor Thorsten Becker, a professor at the Jackson School.

    “We can’t rule out that locally melt doesn’t matter,” said Becker, who designs geodynamic models of the Earth at the Jackson School’s University of Texas Institute for Geophysics. “But I think it drives us to see these observations of melt as a marker of what’s going on in the Earth, and not necessarily an active contribution to anything.”

    The idea to look for a new layer in Earth’s interior came to Hua while studying seismic images of the mantle beneath Turkey during his doctoral research. 

    Intrigued by signs of partly molten rock under the crust, Hua compiled similar images from other seismic stations until he had a global map of the asthenosphere. What he and others had taken to be an anomaly was in fact commonplace around the world, appearing on seismic readings wherever the asthenosphere was hottest. 

    The next surprise came when he compared his melt map with seismic measurements of tectonic movement and found no correlation, despite the molten layer encompassing almost half the Earth. 

    “This work is important because understanding the properties of the asthenosphere and the origins of why it’s weak is fundamental to understanding plate tectonics,” said coauthor Karen Fischer, a seismologist and professor at Brown University who was Hua’s Ph.D. advisor when he began the research.

    The research was funded by the U.S. National Science Foundation. Collaborating institutions included the UT Oden Institute for Computational Engineering and Sciences and Cornell University.

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    University of Texas at Austin (UT Austin)

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  • Powerful earthquake hits Turkey and Syria – media experts available for comment

    Powerful earthquake hits Turkey and Syria – media experts available for comment

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    Newswise — Dr Carmen Solana, course leader for MSc Crisis and Disaster Management at the University of Portsmouth:
    https://www.port.ac.uk/about-us/structure-and-governance/our-people/our-staff/carmen-solana

    Available for Zoom/Skype/WhatsApp interviews

    “Earthquakes cannot be accurately forecast, so prevention of the consequences depends on the country’s preparedness, such as earthquake resistant infrastructure, and efficient response.

    “The resistant infrastructure unfortunately is patchy in South Turkey and especially in Syria, so saving lives now mostly relies on a quick response. The next 24 hours are crucial to find survivors, after 48 hours the number of survivors decreases enormously.”

    Dr Catherine Mottram, Senior Lecturer in Structural Geology and Tectonics at the University of Portsmouth:
    https://www.port.ac.uk/about-us/structure-and-governance/our-people/our-staff/catherine-mottram

    Available for Zoom/Skype/WhatsApp interviews

    “Earthquakes occur when locked portions of faults suddenly ‘break’, resulting in rocks moving rapidly during catastrophic failure events. Aftershocks are usually lower magnitude earthquakes that happen as the crust settles and recovers in the new position. 

    “There is the potential that the 7.5 magnitude shock was related to a second period of movement along a different depth or along strike location on the fault, or on a different fault strand. Geophysicists will be able to reconstruct exactly where movement occurred along the fault by reconstructing data collected by seismometers in the region, so more information should come out in the coming days and weeks about exactly what happened.

    “The earthquake likely occurred on either the East Anatolian Fault or Dead Sea Transform, both of these are strike-slip faults, so a very similar geological setting to the San Andreas Fault in North America. The East Anatolian Fault is also a plate boundary between the broadly northward moving Arabian plate and the westward moving Anatolian plate. The Anatolian plate is very seismically active and is bordered by two strike-slip faults, the North and East Anatolian faults. There is also volcanic activity and other modern geological hazards associated with the boundaries.”

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    University of Portsmouth

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  • Family tree secrets: Island tree populations older, more diverse than expected

    Family tree secrets: Island tree populations older, more diverse than expected

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    Newswise — Tsukuba, Japan—It’s often assumed that island plant and animal populations are just the simple, fragile cousins of those on the mainland. But now, researchers from Japan have discovered that island populations may be a lot tougher and more complex than previously thought.

    In a recently published study, a research group led by the University of Tsukuba has revealed that the northernmost island populations of Siebold’s beech, Fagus crenata, are older and genetically more diverse than expected.

    Island and mainland populations often differ as a result of islands’ geographical isolation, which is often assumed to restrict the genetic diversity of their populations. However, a number of studies on land plants have shown that island populations have considerable genetic diversity despite their remoteness, indicating that the processes underlying their diversity are more complex than previously thought.

    “Although many island populations have existed for thousands of years or longer, the origins of some of them are still unknown,” says Professor Yoshiaki Tsuda, the main author of the study. “This includes Japan’s northernmost island populations of the native species F. crenata.”

    The research group investigated populations of F. crenata on Okushiri Island in the Japan Sea, which is thought to have broken away from the mainland in the Middle Pleistocene (the Ice Age, which occurred 2.58 million to 11,700 years ago), and remained separate ever since. The northward spread of this species began on the mainland approximately 6,000 years ago, after the last glacial maximum (LGM). The researchers studied the genetics of the island’s populations and those of nearby regions, and found that the island’s populations had high genetic diversity, and may not have arisen from a single colonization event.

    The Okushiri Island populations had a comparable number of private alleles (genetic sequences that are present in a single population and essentially absent in other populations) to the populations studied on nearby Hokkaido, which points to the existence of relict populations on Okushiri Island. A relict is a population of organisms that was more widespread or more diverse in the past in a restricted area.

    Taken together with palaeoecological and vegetation studies, as well as the island’s geology, these results indicate that F. crenata persisted in cryptic refugia (places where climatically sensitive species can survive regardless of incompatibility with the regional climate) on the island.

    “Our evidence indicates that populations of this species already existed on Okushiri Island prior to the LGM, and persisted there for longer than previously thought,” explains Professor Tsuda. The results of this study contribute to a growing body of evidence that island plant populations are more genetically diverse than previously estimated, which has implications for research and management of island species conservation, and the study of gene flow between island and mainland populations.

    ###
    This study was supported by JSPS KAKENHI (JP17K07852 and JP20K06152) and Core-to-Core Program (Asia-Africa Science Platforms: JPJSCCB20220007) from the Japan Society for the Promotion of Science and the 27th Pro Natura Fund Grant Program from the Pro Natura Foundation Japan.
     

    Original Paper

    The article, “Possible northern persistence of Siebold’s beech, Fagus crenata, at its northernmost distribution limit on an island in Japan Sea: Okushiri Island, Hokkaido,” was published in Frontiers in Plant Science at DOI: 10.3389/fpls.2022.990927

    Correspondence

    Associate Professor TSUDA Yoshiaki
    Faculty of Life and Environmental Sciences, University of Tsukuba

    Related Link

    Faculty of Life and Environmental Sciences
    Sugadaira Research Station, Mountain Science Center

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    University of Tsukuba

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  • NASA says 2022 fifth warmest year on record, warming trend continues

    NASA says 2022 fifth warmest year on record, warming trend continues

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    Newswise — Earth’s average surface temperature in 2022 tied with 2015 as the fifth warmest on record, according to an analysis by NASA. Continuing the planet’s long-term warming trend, global temperatures in 2022 were 1.6 degrees Fahrenheit (0.89 degrees Celsius) above the average for NASA’s baseline period (1951-1980), scientists from NASA’s Goddard Institute for Space Studies (GISS) in New York reported.

    “This warming trend is alarming,” said NASA Administrator Bill Nelson. “Our warming climate is already making a mark: Forest fires are intensifying; hurricanes are getting stronger; droughts are wreaking havoc and sea levels are rising. NASA is deepening our commitment to do our part in addressing climate change. Our Earth System Observatory will provide state-of-the-art data to support our climate modeling, analysis and predictions to help humanity confront our planet’s changing climate.”

    The past nine years have been the warmest years since modern recordkeeping began in 1880. This means Earth in 2022 was about 2 degrees Fahrenheit (or about 1.11 degrees Celsius) warmer than the late 19th century average.

    “The reason for the warming trend is that human activities continue to pump enormous amounts of greenhouse gases into the atmosphere, and the long-term planetary impacts will also continue,” said Gavin Schmidt, director of GISS, NASA’s leading center for climate modeling.

    Human-driven greenhouse gas emissions have rebounded following a short-lived dip in 2020 due to the COVID-19 pandemic. Recently, NASA scientists, as well as international scientists, determined carbon dioxide emissions were the highest on record in 2022. NASA also identified some super-emitters of methane – another powerful greenhouse gas – using the Earth Surface Mineral Dust Source Investigation instrument that launched to the International Space Station last year.

    The Arctic region continues to experience the strongest warming trends – close to four times the global average – according to GISS research presented at the 2022 annual meeting of the American Geophysical Union, as well as a separate study.

    Communities around the world are experiencing impacts scientists see as connected to the warming atmosphere and ocean. Climate change has intensified rainfall and tropical storms, deepened the severity of droughts, and increased the impact of storm surges. Last year brought torrential monsoon rains that devastated Pakistan and a persistent megadrought in the U.S. Southwest. In September, Hurricane Ian became one of the strongest and costliest hurricanes to strike the continental U.S.  

    Tracking Our Changing Planet

    NASA’s global temperature analysis is drawn from data collected by weather stations and Antarctic research stations, as well as instruments mounted on ships and ocean buoys. NASA scientists analyze these measurements to account for uncertainties in the data and to maintain consistent methods for calculating global average surface temperature differences for every year. These ground-based measurements of surface temperature are consistent with satellite data collected since 2002 by the Atmospheric Infrared Sounder on NASA’s Aqua satellite and with other estimates.

    NASA uses the period from 1951-1980 as a baseline to understand how global temperatures change over time. That baseline includes climate patterns such as La Niña and El Niño, as well as unusually hot or cold years due to other factors, ensuring it encompasses natural variations in Earth’s temperature.

    Many factors can affect the average temperature in any given year. For example, 2022 was one of the warmest on record despite a third consecutive year of La Niña conditions in the tropical Pacific Ocean. NASA scientists estimate that La Niña’s cooling influence may have lowered global temperatures slightly (about 0.11 degrees Fahrenheit or 0.06 degrees Celsius) from what the average would have been under more typical ocean conditions.

    A separate, independent analysis by the National Oceanic and Atmospheric Administration (NOAA) concluded that the global surface temperature for 2022 was the sixth highest since 1880. NOAA scientists use much of the same raw temperature data in their analysis and have a different baseline period (1901-2000) and methodology. Although rankings for specific years can differ slightly between the records, they are in broad agreement and both reflect ongoing long-term warming.

    NASA’s full dataset of global surface temperatures through 2022, as well as full details with code of how NASA scientists conducted the analysis, are publicly available from GISS.

    GISS is a NASA laboratory managed by the Earth Sciences Division of the agency’s Goddard Space Flight Center in Greenbelt, Maryland. The laboratory is affiliated with Columbia University’s Earth Institute and School of Engineering and Applied Science in New York.

    For more information about NASA’s Earth science programs, visit: 

    https://www.nasa.gov/earth

     

     -end-

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    NASA Goddard Space Flight Center

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  • New biography of famous palaeontologist Mary Anning unearthed from University of Bristol archives

    New biography of famous palaeontologist Mary Anning unearthed from University of Bristol archives

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    Newswise — A short biography of pioneering scientist Mary Anning, written in the final ten years of her life, has been made public for the very first time.

    Penned by George Roberts (1804–1860), who ran a private school opposite Anning’s fossil shop in Lyme Regis, and preserved in the Special Collections of the University of Bristol Library, the work has been published by Dr Michael Taylor of National Museums Scotland and University of Leicester and Professor Michael Benton of Bristol’s School of Earth Sciences.

    Mary Anning (1799–1847) of Lyme Regis has been the subject of recent books and films, such as Tracy Chevalier’s Remarkable Creatures, and Ammonite, in which she was portrayed by Kate Winslet, because of her importance in the early days of palaeontology. She collected some of the first marine reptiles – ichthyosaurs and plesiosaurs – from the Jurassic period of the Dorset coast. Noted professors relied on her work to provide insights into the life of the past.

    Mary Anning has become an icon of the often-forgotten contributions of women to science, and the campaign to get children, especially girls, interested in geology. But, in her day, she was a curiosity, another poor person in the Regency seaside resort of Lyme Regis.

    “When the Library sent me a copy of the four-page manuscript, I found that it was based partly on a passage in Roberts’s history of Lyme Regis,” said Dr Taylor. “Roberts wrote books like ‘The Beauties of Lyme Regis’ for tourists, and he collected interesting pieces of information. We were able to confirm Anning expert Hugh Torrens’s suggestion that it was by Roberts, by identifying Roberts’s handwriting, and comparing the corrections and even a mistake with a particular date which Roberts had handwritten into his own copy of his history. So, it wasn’t just someone else copying from his book. It looks as if it was written as a dictionary entry or a section for a future book.”

    “This memoir is valuable,” said Prof Benton. “One or two visitors to Lyme Regis mentioned Mary Anning and her little fossil shop, and she was obviously widely known to natural scientists in London, Bristol, Oxford, and Cambridge. But normally they would not enquire into her life in any detail. Admittedly though, when she died at the relatively young age of 48, she had obituaries in various papers and scientific journals.”

    Dr Taylor said: “These short obituaries were often copied from one written by George Roberts. George Roberts lived in Lyme Regis and met her many times. He describes how she was struck by lightning as a baby, and then how at the age of about ten she began collecting fossils, and how she sold her first find, an ammonite to a passing lady in the street for half a crown.”

    There are further details of her discoveries of fossil reptiles, including the first ichthyosaur fossil studied by scientists. It was described by Sir Everard Home in 1818. Mary Anning was granted a government annuity of £25 per year in 1836 thanks to an intervention by Fellows of the Geological Society of London, and she died of breast cancer in 1847.

    “We dated the manuscript as written some time in 1837–47,” added Dr Taylor, “because there is an ‘1837’ watermark in the paper, and Anning was described as a ‘living worthy’. Later,  Roberts took the manuscript, deleted mention of Anning as alive, and added information on her death to make it into an obituary, presumably just after she died. But it seems never to have been published at its full length.”

    Prof Benton concluded: “We are very pleased that we are able to publish the document in full.

    “In the paper, we show detailed photographs of all four pages of the document, as well as our reading of the various versions and modifications. George Roberts was the locally-based author who reported the news from Lyme Regis to various newspapers and wrote his own books, so it makes complete sense that he would have written about Mary Anning as a well-known celebrity of the town.”

    Paper:

    ‘The life of Mary Anning, fossil collector of Lyme Regis: a contemporary biographical memoir by George Roberts’ by Michael A. Taylor and Michael J. Benton in Journal of the Geological Society.

     

    Notes to Editors

    The memoir (DM Ref SCUBL DM1186/5/1) is in the collection of books and manuscripts in the history of geology made by Joan M. Eyles (1907–1986) and Victor A. Eyles (1895–1978) and donated by Joan Eyles to the University of Bristol Library.

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    University of Bristol

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  • New Research Finds Satellite Imagery Could Improve Fossil-Hunting at Remote Sites

    New Research Finds Satellite Imagery Could Improve Fossil-Hunting at Remote Sites

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    Paleontologists discover satellite imagery could help paleontologists spot promising fossil sites before trekking into remote places.

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    University of Oregon

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  • 20 new gurgling and creaking frog species from Madagascar named

    20 new gurgling and creaking frog species from Madagascar named

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    Newswise — Taxonomists are working against the clock to discover and catalogue new species before they disappear, to make it possible to protect our planet’s remaining biodiversity. Major strides are needed to move towards completing the biological inventory on Earth. Now, a large international team has made a huge stride forward on the taxonomy of Madagascar’s frogs, naming 20 new species at once. The article was published under open access in the journal Megataxa.

    The frogs belong to the genus Mantidactylus subgenus Brygoomantis, which contained just 14 species until now. These small, brown frogs are ubiquitous along streams in Madagascar’s humid forests, but are inconspicuous to the eye. The males emit very subtle advertisement calls to attract females. ‘The calls typically sound like a creaking door, or a gurgling stomach’ says lead author, Dr Mark D. Scherz, Curator of Herpetology at the Natural History Museum of Denmark, ‘Finding, recording, and catching calling individuals of these frogs is a real challenge, but has proven critically important for the discovery and description of these many new species. That means a lot of time on hands and knees in the mud.’

    The team has been building to this for a long time. ‘This is the culmination of intensive fieldwork across Madagascar over more than 30 years’ says Dr Frank Glaw, Curator of Herpetology at the Zoologische Staatssammlung München, in Munich, Germany, ‘Our dataset contains genetic data from over 1300 frogs, and measurements of several hundred specimens.’

    One key tool in the authors’ arsenal was the use of cutting-edge ‘museomics’, where DNA is sequenced from old museum material. This is often difficult, because DNA degrades over time and due to various chemicals that are used to preserve animal specimens. But using an approach called ‘DNA Barcode Fishing’, the team were able to get useable DNA sequences from most of the relevant museum material. ‘Museomics gave definitive identifications of sometimes very ambiguous-looking specimens,’ says senior author, Professor Miguel Vences of the Technische Universität Braunschweig, ‘This gives us a level of confidence in our species descriptions that was not previously possible based on morphology alone.’

    Even this huge stride forward doesn’t seem to be the last word on the subgenus Brygoomantis. ‘There are still several Brygoomantis lineages that are probably separate species, but that we didn’t have enough data or material for,’ says Dr Andolalao Rakotoarison, co-chair of the Amphibian Specialist Group for Madagascar, ‘Even for those species for which we have names, we know almost nothing about their biology or ecology. We need a lot more field research on these frogs, and more specimens in museum collections, to really gain a good understanding of them.’

    Citation: Scherz, M.D., Crottini, A., Hutter, C.R., Hildenbrand, A., Andreone, F., Fulgence, T.R., Köhler, G., Ndraintsoa, S.H., Ohler, A., Preick, M., Rakotoarison, A., Rancilhac, L., Raselimanana, A.P., Riemann, J.C., Rödel, M.-O., Rosa, G.M., Streicher, J.W., Vieites, D.R., Köhler, J., Hofreiter, M., Glaw, F. & Vences, M. (2022) An inordinate fondness for inconspicuous brown frogs: integration of phylogenomics, archival DNA analysis, morphology, and bioacoustics yields 24 new taxa in the subgenus Brygoomantis (genus Mantidactylus) from Madagascar. Megataxa. https://doi.org/10.11646/megataxa.7.2.1

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    University of Copenhagen

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  • FSU geologist available to comment on Mauna Loa eruption

    FSU geologist available to comment on Mauna Loa eruption

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    Newswise — The Hawaiian volcano Mauna Loa, the largest active volcano on the planet, is erupting for the first time since 1984.

    Vincent Salters, director of the Geochemistry Program at the National High Magnetic Field Laboratory at Florida State University, is available to speak to media about the geology behind this eruption.

    Salters researches the cycling of elements in the Earth and the chemical and physical processes that lead to the planet’s different layers. He studies samples from deeper in the Earth that come to the surface during volcanic eruptions or through large faults. He has extensively published on the chemistry and origin of volcanism at hot spots, such as Hawaii, as well as mid-ocean ridges.

    He is a fellow of the American Geophysical Union and editor of AGU Advances.

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    Florida State University

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  • Volcanology expert available to comment on the eruption of Mauna Loa

    Volcanology expert available to comment on the eruption of Mauna Loa

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    Volcanology expert available to comment on the eruption of Mauna Loa.

    Dr Carmen Solana, Reader in Volcanology and Risk Communications at the University of Portsmouth, is available for interview. 

    Dr Solana said: “Mauna Loa is finally erupted after many years in repose, and it seems to be erupting from the summit, which is the less dangerous scenario as lava should be contained within the caldera. Scientists in the HVO will be watching for the potential opening of an erupting fissure in the flank that would mean that lava could reach inhabited areas quickly. This is a very exciting occurrence, we have been waiting for a while for Mauna Loa to reawake. 

    “It is the largest volcano in the world and mainly erupts lava, but in the past it has reached large distances and into inhabited areas.”

     

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    University of Portsmouth

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  • FSU researchers: Rapid fluctuations in oxygen levels coincided with Earth’s first mass extinction

    FSU researchers: Rapid fluctuations in oxygen levels coincided with Earth’s first mass extinction

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    Newswise — Rapid changes in marine oxygen levels may have played a significant role in driving Earth’s first mass extinction, according to a new study led by Florida State University researchers.

    About 443 million years ago, life on Earth was undergoing the Late Ordovician mass extinction, or LOME, which eliminated about 85% of marine species. Scientists have long studied this mass extinction and continue to investigate its possible causes, such as reduced habitat loss in a rapidly cooling world or persistent low-oxygen conditions in the oceans.

    By measuring isotopes of the element thallium — which shows special sensitivity to changes in oxygen in the ancient marine environment — the research team found that previously documented patterns of this mass extinction coincided with an initial rapid decrease in marine oxygen levels followed by a rapid increase in oxygen. Their work is published online in the journal Science Advances.

    “Paleontologists have noted that there were several groups of organisms, such as graptolites and brachiopods, that started to decline very early in this mass extinction interval, but we didn’t really have any good evidence of an environmental or climate signature to tie that early decline of these groups to a particular mechanism,” said co-author Seth Young, an associate professor in the Department of Earth, Ocean and Atmospheric Science. “This paper can directly link that early phase of extinction to changes in oxygen. We see a marked change in thallium isotopes at the same time these organisms start their steady decline into the main phase of the mass extinction event.”

    That decrease in oxygen was immediately followed by an increase. This rapid shift in oxygen coincided with the traditional first die-off of mass extinction and major ice sheet growth over the ancient South Pole.

    “Turbulence in oxygen levels in oceanic waters is really what seems to have been pretty problematic for organisms that were living in the Late Ordovician at that time, which might have been adapted to cope with low oxygen conditions initially or vice versa,” Young said. “The fact that oxygen levels in the oceans next to the continents switching back and forth over short geologic time scales (a few hundred thousand years) really did seem to play havoc with these marine ecosystems.”

    The Late Ordovician extinction was one of five major mass extinctions in Earth’s history and the only one scientists are confident took place in what are called “icehouse” conditions, in which widespread ice sheets are present on Earth’s surface. Earth is currently experiencing icehouse conditions and loss of biodiversity, which makes this ancient mass extinction an important analog for present-day conditions, along with trying to understand Earth’s future as our climate continues to warm and ice sheets recede.

    Previous research into environmental conditions surrounding the LOME used evidence found in limestones from more oxygenated settings, but this study used shales that were deposited in deeper, oxygen-poor water, which record different geochemical signatures, allowing the researchers to make conclusions about global marine conditions, rather than for local conditions.

    “The discovery of the initial expansion of low-oxygen conditions on a global level and the coincidence with the early phases of decline in marine animals helps paint a clearer picture of what was happening with this extinction event,” said lead author Nevin Kozik, a visiting assistant professor at Occidental College and former FSU doctoral student.

    Co-authors on this paper were doctoral student Sean Newby and associate professor Jeremy Owens of FSU; former FSU postdoctoral scholar and current assistant professor at the College of Charleston Theodore Them; Mu Liu and Daizhao Chen of the Chinese Academy of Sciences; Emma Hammarlund of Lund University; and David Bond of the University of Hull.

    This research was supported by the National Science Foundation, the American Chemical Society, the Sloan Research Foundation and the Geological Society of America.

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    Florida State University

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  • Earth can regulate its own temperature over millennia, new study finds

    Earth can regulate its own temperature over millennia, new study finds

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    Newswise — The Earth’s climate has undergone some big changes, from global volcanism to planet-cooling ice ages and dramatic shifts in solar radiation. And yet life, for the last 3.7 billion years, has kept on beating.

    Now, a study by MIT researchers in Science Advances confirms that the planet harbors a “stabilizing feedback” mechanism that acts over hundreds of thousands of years to pull the climate back from the brink, keeping global temperatures within a steady, habitable range.

    Just how does it accomplish this? A likely mechanism is “silicate weathering” — a geological process by which the slow and steady weathering of silicate rocks involves chemical reactions that ultimately draw carbon dioxide out of the atmosphere and into ocean sediments, trapping the gas in rocks.

    Scientists have long suspected that silicate weathering plays a major role in regulating the Earth’s carbon cycle. The mechanism of silicate weathering could provide a geologically constant force in keeping carbon dioxide — and global temperatures — in check. But there’s never been direct evidence for the continual operation of such a feedback, until now.

    The new findings are based on a study of paleoclimate data that record changes in average global temperatures over the last 66 million years. The MIT team applied a mathematical analysis to see whether the data revealed any patterns characteristic of stabilizing phenomena that reined in global temperatures on a  geologic timescale.

    They found that indeed there appears to be a consistent pattern in which the Earth’s temperature swings are dampened over timescales of hundreds of thousands of years. The duration of this effect is similar to the timescales over which silicate weathering is predicted to act.

    The results are the first to use actual data to confirm the existence of a stabilizing feedback, the mechanism of which is likely silicate weathering. This stabilizing feedback would explain how the Earth has remained habitable through dramatic climate events in the geologic past.

    “On the one hand, it’s good because we know that today’s global warming will eventually be canceled out  through this stabilizing feedback,” says Constantin Arnscheidt, a graduate student in MIT’s Department of Earth, Atmospheric, and Planetary Sciences (EAPS). “But on the other hand, it will take hundreds of thousands of years to happen, so not fast enough to solve our present-day issues.”

    The study is co-authored by Arnscheidt and Daniel Rothman, professor of geophysics at MIT.

    Stability in data

    Scientists have previously seen hints of a climate-stabilizing effect in the Earth’s carbon cycle: Chemical analyses of ancient rocks have shown that the flux of carbon in and out of Earth’s surface environment has remained relatively balanced, even through dramatic swings in global temperature. Furthermore, models of silicate weathering predict that the process should have some stabilizing effect on the global climate. And finally, the fact of the Earth’s enduring habitability points to some inherent, geologic check on extreme temperature swings.

    “You have a planet whose climate was subjected to so many dramatic external changes. Why did life survive all this time? One argument is that we need some sort of stabilizing mechanism to keep temperatures suitable for life,” Arnscheidt says. “But it’s never been demonstrated from data that such a mechanism has consistently controlled Earth’s climate.”

    Arnscheidt and Rothman sought to confirm whether a stabilizing feedback has indeed been at work, by looking at  data of global temperature fluctuations through geologic history. They worked with a range of global temperature records compiled by other scientists, from the chemical composition of ancient marine fossils and shells, as well as preserved Antarctic ice cores.

    “This whole study is only possible because there have been great advances in improving the resolution of these deep-sea temperature records,” Arnscheidt notes. “Now we have data going back 66 million years, with data points at most thousands of years apart.”

    Speeding to a stop

    To the data, the team applied the mathematical theory of stochastic differential equations, which is commonly used to reveal patterns in widely fluctuating datasets.

    “We realized this theory makes predictions for what you would expect Earth’s temperature history to look like if there had been feedbacks acting on certain timescales,” Arnscheidt explains.

    Using this approach, the team analyzed the history of average global temperatures over the last 66 million years, considering the entire period over different timescales, such as tens of thousands of years versus hundreds of thousands, to see whether any patterns of stabilizing feedback emerged within each timescale.

    “To some extent, it’s like your car is speeding down the street, and when you put on the brakes, you slide for a long time before you stop,” Rothman says. “There’s a timescale over which frictional resistance, or a stabilizing feedback, kicks in, when the system returns to a steady state.”

    Without stabilizing feedbacks, fluctuations of global temperature should grow with timescale. But the team’s analysis revealed a regime in which fluctuations did not grow, implying that a stabilizing mechanism reigned in the climate before fluctuations grew too extreme. The timescale for this stabilizing effect — hundreds of thousands of years — coincides with what scientists predict for silicate weathering.

    Interestingly, Arnscheidt and Rothman found that on longer timescales, the data did not reveal any stabilizing feedbacks. That is, there doesn’t appear to be any recurring pull-back of global temperatures on timescales longer than a million years. Over these longer timescales, then, what has kept global temperatures in check?

    “There’s an idea that chance may have played a major role in determining why, after more than 3 billion years, life still exists,” Rothman offers.

    In other words, as the Earth’s temperatures fluctuate over longer stretches, these fluctuations may just happen to be small enough in the geologic sense, to be within a range that a stabilizing feedback, such as silicate weathering, could periodically keep the climate in check, and more to the point, within a habitable zone.

    “There are two camps: Some say random chance is a good enough explanation, and others say there must be a stabilizing feedback,” Arnscheidt says. “We’re able to show, directly from data, that the answer is probably somewhere in between. In other words, there was some stabilization, but pure luck likely also played a role in keeping Earth continuously habitable.”

    This research was supported in part by a MathWorks fellowship and the National Science Foundation.

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    Massachusetts Institute of Technology (MIT)

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  • Case study proposes framework for analyzing U.S.-China geo-political tensions in Indo-Pacific

    Case study proposes framework for analyzing U.S.-China geo-political tensions in Indo-Pacific

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    Newswise — Social sciences and international relations experts at Hiroshima University in Japan have proposed a new framework for studying the immensely complex power dynamics between China and the U.S., and its allies bordering the Pacific Ocean – “hybrid balancing.” The concept evolved out of “hybrid warfare,” which was an outgrowth of the Cold War between the U.S. and the former Soviet Union, when war became more about public perception, trust in governments, and economic leverage than bullets and tanks.

    Since then, and especially since the invasion of Crimea by the Russian Federation in March 2014, hybrid warfare has been popularized to the extent that the concept has become a cornerstone of security studies worldwide, according to Assistant Professor Ryuta Ito of the Graduate School of Humanities and Social Sciences, who wrote and published the case study in peer-reviewed journal International Affairs in early November 2022.

    “Hybrid warfare has recently attracted scholarly attention,” Ito said. “Despite its importance, hybrid warfare research remains underdeveloped, as it sometimes falls into the trap of ‘simplistic hypothesis testing’, which focuses on narrowly defined military factors while downplaying the fundamentals of international politics (e.g. balancing and diplomacy). My recent article fills this gap by constructing a new theoretical concept called ‘hybrid balancing’ by introducing the essence of hybrid warfare into classical realism, based on the scientific realism in the philosophy of science as a meta-theoretical foundation.”

    Political scientists and international relations academics and analysts hope to better understand how China uses its vast social and economic influence across the Indo-Pacific region to maintain favorable trade conditions while also seeking to quell the proliferation of liberal Western cultural ideals. Geographically, the Indo-Pacific region extends from the Indian Ocean to the Pacific Ocean (especially the western Pacific): namely, from the eastern coast of Africa and the environs of Madagascar, through the waters around the Philippines and Indonesia between the two oceans, to the eastern edge of Oceania, Ito wrote in the case study. “Politically, since 2010, it has gradually established itself as a strategic concept in the foreign policy lexicon of some countries, particularly Australia, India, Japan, and the United States.”

    “Rather than being a new form of conflict, hybrid warfare is a strategy that the belligerent uses to advance its political goals on the battlefield by applying military force subversively,” Ito wrote, referencing a 2016 paper in International Affairs.

    The interest and urgency surrounding the study of hybrid warfare are growing in part because of the conflict between Ukraine and the Russian Federation. “As has been widely reported, the war in Ukraine has the potential to demonstrate costs and consequences of a powerful nation attempting to overtake a smaller, yet highly productive and resource-rich state such as Taiwan,” Ito said. “In the case of China and Taiwan, the stakes in an all-out military conflict would be on the orders of magnitude greater than what we’re seeing in Ukraine, so a conventional war is virtually unthinkable. However, hybrid balancing as I’ve described better encapsulates the ebb and flow of power in the Indo-Pacific.”

    What has emerged in the past decade in response to China’s hybrid balancing posturing is the “Free and Open Indo-Pacific (FOIP) Coalition,” which includes pro-democracy nations across the Indo-Pacific and led by economic heavyweights U.S., Japan, and Australia.

    “It is apparent to us that China is engaging in hybrid balancing in this region to counter the liberal democratic coalition advancing the FOIP strategy,” Ito said. “Further study is warranted as tensions across this economically crucial region continue to grow. Cases other than China’s use of hybrid warfare in the Indo-Pacific are needed to verify hybrid balancing more robustly. Since our article’s case-study is a plausibility probe, which aims not to test a theory but merely to illustrate it to show that the argument is sufficiently grounded in evidence to justify further research, the next step may be rigorous case-studies to confirm the logic of hybrid balancing.”

    ###

    About Hiroshima University

    Since its foundation in 1949, Hiroshima University has striven to become one of the most prominent and comprehensive universities in Japan for the promotion and development of scholarship and education. Consisting of 12 schools for undergraduate level and 4 graduate schools, ranging from natural sciences to humanities and social sciences, the university has grown into one of the most distinguished comprehensive research universities in Japan.
    English website: https://www.hiroshima-u.ac.jp/en

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    Hiroshima University

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  • Linking mass extinctions to the expansion and radiation of land plants

    Linking mass extinctions to the expansion and radiation of land plants

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    Newswise — Boulder, Colo., USA: The Devonian Period, 419 to 358 million years ago, was one of the most turbulent times in Earth’s past and was marked by at least six significant marine extinctions, including one of the five largest mass extinctions ever to have occurred. Additionally, it was during the Devonian that trees and complex land plants similar to those we know today first evolved and spread across the landscape. This evolutionary advancement included the development of significant and complex root systems capable of affecting soil biogeochemistry on a scale the ancient Earth had yet to experience.

    It has been theorized that these two seemingly separate events, marine extinctions and plant evolution and expansion, were intricately linked in the Devonian. Specifically, it has been proposed that plant evolution and root development occurred so rapidly and on such a massive scale that nutrient export from the land to the ancient oceans would have drastically increased. This scenario is seen in modern systems where anthropogenically sourced nutrient export has vastly increased the nutrient load into areas such as the Gulf of Mexico and the Great Lakes, leading to large-scale algal blooms that ultimately deplete the oxygen in the water column. This effect, known as eutrophication, magnified on a global scale, would have been catastrophic to ancient oceans, fueling algal blooms that would have depleted most of the ocean’s oxygen.

    The key to linking mass extinctions and the expansion and radiation of land plants lies in identifying a nutrient flux elevated above background levels, linking that nutrient flux to either indirect or direct evidence of the presence of deeply rooting land plants and finally showing that this phenomenon occurred in multiple locations and times.

    This study, the first of its kind, was able to do precisely that by utilizing geochemical records from ancient lake deposits in Greenland, northern Scotland, and Orkney. Utilizing lake records, elevated values of the nutrient phosphorus were detected in five distinct locations during the height of plant evolution and expansion in the Devonian. In each case, elevated values of nutrient input were coincident with evidence of the presence of early trees in the form of fossilized spores and, in some cases, fossilized stems of the earliest deeply rooting tree, Archaeopteris. In two cases, that evidence coincided with a Devonian marine extinction event, including the most significant Devonian mass extinction, the Frasnian–Famennian extinction (also known as the Late Devonian mass extinction).

    Additionally, this study, published yesterday in the Geological Society of America Bulletin, linked the periodic wet/dry climate cycles known to exist in the region during the Devonian with specific episodes of plant colonization. While elevated nutrient export was noted during both wet and dry climate cycles, the most significant export events occurred during wet cycles, suggesting that plant expansion was episodic and tied to climate cyclicity.

    The episodic nature of plant expansion could help explain why there are at least six significant marine extinctions in the Devonian. While the scope of this study was limited to a single geographic region, it is likely that these events occurred throughout the Devonian Earth. The colonization of different types of land plants in different regions and at different times would have resulted in episodic nutrient pulses significant enough to sustain eutrophication and cause (or at least contribute) to the numerous marine extinction events throughout the mid- to Late Devonian.

    FEATURED ARTICLE
    Enhanced terrestrial nutrient release during the Devonian emergence and expansion of forests: Evidence from lacustrine phosphorus and geochemical records
    Matthew Smart; Gabriel Filippelli; William Gilhooly; John Marshall; Jessica Whiteside
    Contact: Matthew Smart, [email protected], Indiana University–Purdue University Indianapolis, Earth Sciences, Indianapolis, Indiana
    URL: https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/doi/10.1130/B36384.1/618814/Enhanced-terrestrial-nutrient-release-during-the

    GSA BULLETIN articles published ahead of print are online at https://bulletin.geoscienceworld.org/content/early/recent . Representatives of the media may obtain complimentary copies of articles by contacting Kea Giles. Please discuss articles of interest with the authors before publishing stories on their work, and please make reference to The Geological Society of America Bulletin in articles published. Non-media requests for articles may be directed to GSA Sales and Service, [email protected]

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    Geological Society of America (GSA)

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  • A 5.1 magnitude earthquake strikes near San Jose, US Geological Survey reports | CNN

    A 5.1 magnitude earthquake strikes near San Jose, US Geological Survey reports | CNN

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    CNN
     — 

    The US Geological Survey (USGS) is reporting a 5.1 magnitude earthquake in Seven Trees, near San Jose, California.

    Preliminary information from the USGS says the quake was 6.9 kilometers (4.2 miles) deep and hit around 11:42 a.m. PT Tuesday.

    “Additional shaking from aftershocks can be expected in the region. We are continuing to monitor this region,” the California Geological Survey tweeted.

    Earthquakes are measured using seismographs, which monitor the seismic waves that travel through the Earth after an earthquake strikes. Quakes between 2.5 and 5.4 in magnitude are often felt, but only cause minor damage, according to Michigan Tech’s UPSeis website.

    This is a developing story.

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  • Witte Museum Paleontologist Names New Species of Fossil Crocodile

    Witte Museum Paleontologist Names New Species of Fossil Crocodile

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    Press Release
    –


    updated: Sep 14, 2017


    SAN ANTONIO, Texas, September 14, 2017 (Newswire.com)
    –
    Dr. Thomas Adams, Witte Museum Curator of Paleontology and Geology, has described and named a new species of fossil crocodile discovered in North Texas. Dr. Adams, the lead author of a paper outlining the find, describes Deltasuchus motherali as one of the “top predators in its ecosystem.”

    As Curator of Paleontology and Geology, Dr. Adams developed the content for the Naylor Family Dinosaur Gallery at the Witte Museum which includes Deinocuchus riograndensis, another prehistoric crocodile that lived in what we now call Texas. The giant prehistoric crocodile is one of the most popular ancient animals in the dinosaur gallery.

    Dr. Thomas Adams, Witte Museum Curator of Paleontology and Geology, has described and named a new species of fossil crocodile discovered in North Texas. Dr. Adams, the lead author of a paper outlining the find, describes Deltasuchus motherali as one of the ‘top predators in its ecosystem.’

    Dr. Thomas Adams, Curator of Paleontology and Geology

    Deltasuchus, a relative of modern crocodiles, lived around 95 million years ago, and ruled the coastlines and waterways of what would one day become north-central Texas. Adults of the newly discovered and described species Deltasuchus motherali grew up to 20 feet (6 meters) long, and left behind bite marks on the fossilized bones of prey animals, suggesting that it was an opportunistic animal, eating much of what was in its environment, from turtles to dinosaurs.

    Dr. Adams, along with co-authors Drs. Chris Noto, at the University of Wisconsin-Parkside, and Stephanie Drumheller-Horton, at the University of Tennessee, published the description of the new croc species in the latest issue of the Journal of Vertebrate Paleontology. A unique aspect of the find is that it was discovered in the heart of the Dallas-Fort Worth Metroplex, a place that normally is not associated with ancient fossils.

    The site that produced the new species was discovered in Arlington, Texas, in 2003 by amateur fossil hunters Art Sahlstein, Bill Walker and Phil Kirchoff. Dubbed the Arlington Archosaur Site (AAS), the area is undergoing rapid residential development, and paleontologists have been working with local volunteers and fossil enthusiasts to excavate the site over the last decade. Deltasuchus motherali is named for one of those volunteers, Austin Motheral, who first uncovered the fossils of this particular croc with a small tractor when he was 15 years old. Work on the site is supported by a grant from the National Geographic Society, which is funding continued excavations and study of this unique fossil locality. Fossils from the site, including the Deltasuchus motherali bones, are part of the collections of the nearby Perot Museum of Nature and Science in Dallas, Texas.

    Deltasuchus is the first of what may prove to be several new species described from this prolific fossil site. The locality preserves a surprisingly complete ancient ecosystem ranging from 95 million to 100 million years old, and its fossils are filling in an important gap in our understanding of ancient North American land and freshwater ecosystems. While most of Texas was covered by a shallow sea at this time, the Dallas-Fort Worth area was part of a large peninsula that jutted out into this sea from the northeast. This peninsula was a lush environment of river deltas and swamps that teemed with wildlife, including dinosaurs, crocodiles, turtles, mammals, amphibians, fish, invertebrates, as well as plants.

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    About the Witte Museum:

    Founded in 1926, the Witte Museum is where Science, Nature and Culture Meet, through the lens of Texas Deep Time, and the themes of Land, Water, Sky. Located on the banks of the San Antonio River in Brackenridge Park, the Witte Museum is San Antonio’s premier museum promoting lifelong learning through innovative exhibitions, programs and collections in natural history, science and South Texas heritage.

    Source: Witte Museum

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