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  • richardmitnick 3:55 pm on January 23, 2022 Permalink | Reply
    Tags: "A Deep-Space Origin for Volatile-Rich Asteroids", Eos, Some of the main belt asteroids contain ammoniated clays which are not seen in the meteorites., Spectral data and modeling suggest that volatile-rich main-belt asteroids initially formed at much greater distances from the Sun (>10 AU)., The origin of the Earth’s volatiles (e.g., This is important because ammonia is not expected to be stable so close to the Sun., This study bolsters other recent isotopic arguments that an outer solar system reservoir contributed significantly to the Earth’s growth., water) is a perennial puzzle.   

    From Eos : “A Deep-Space Origin for Volatile-Rich Asteroids” 

    From AGU
    Eos news bloc

    From Eos

    19 January 2022
    Francis Nimmo

    Spectral data and modeling suggest that volatile-rich main-belt asteroids initially formed at much greater distances from the Sun (>10 AU).

    1
    Processes envisaged to have taken place. The body accretes (1) and then heats up and differentiates (2) into a rock rich-interior and an icier exterior. The body then refreezes (3) with the inner and outer regions having different mineralogies and spectral absorptions. On impact disruption (4) fragments from the core will preferentially survive to become meteorites. Credit: Kurokawa et al., 2021, (Figure 7).

    The origin of the Earth’s volatiles (e.g., water) is a perennial puzzle.

    Most likely they come primarily from volatile-rich (“carbonaceous”) meteorites, which are spectrally similar to volatile-rich asteroids in the main belt.

    But as Kurokawa et al. [2021] [AGU Advances] show, the similarity is not exact: some of the main belt asteroids contain ammoniated clays which are not seen in the meteorites.

    This is important because ammonia is not expected to be stable so close to the Sun.

    Instead, Kurokawa et al. propose that the volatile-rich asteroids formed at greater distances (>10 AU) and were then scattered inwards to the main belt.

    The absence of ammoniated clays in meteorites is explained by positing a layered structure, with the more indurated, ammonia-free rocky core expected to survive impact disruption and atmospheric re-entry.

    This study bolsters other recent isotopic arguments that an outer solar system reservoir contributed significantly to the Earth’s growth.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 3:30 pm on January 23, 2022 Permalink | Reply
    Tags: "Radiometric Dating Sheds Light on Tectonic Debate", , , Eos, , Obduction-ophiolites-slices of oceanic crust and mantle atop a continental plate—offer uncommon opportunities to view seafloor geology from the comfort of land., Obduction: the oceanic plate ends up atop the more buoyant continental plate instead of diving below it., Subduction: the denser oceanic plate is pushed below the continental plate., The episode occurred approximately 81–77 million years ago when the Arabian continental plate subducted to the northeast below the Samail Ophiolite., The Samail Ophiolite (Oman–United Arab Emirates) is frequently studied as a model of obduction because of its well-exposed and well-studied geology., This conclusion refutes previously published estimates that continental subduction in Oman started 110 million years ago and may have occurred over two distinct episodes.   

    From Eos : “Radiometric Dating Sheds Light on Tectonic Debate” 

    From AGU
    Eos news bloc

    From Eos

    21 January 2022
    Aaron Sidder

    The emplacement of the Samail Ophiolite in Oman has been a source of disagreement among geologists. New state-of-the-art research offers a fresh perspective on its timing and geometry.

    1

    At the far edges of continents, where the continental shelf transitions into the deep ocean, continental and oceanic plates come face to face. At many of these margins, the denser oceanic plate is pushed below the continental plate in a process called subduction. However, in some cases, known as obduction, the oceanic plate ends up atop the more buoyant continental plate instead of diving below it.

    Obduction zones are unique because they foster the recycling of surface continental material to the deep mantle, which happens infrequently, and they have formed almost exclusively in the past billion years of Earth’s history. The resulting ophiolites—slices of oceanic crust and mantle atop a continental plate—offer uncommon opportunities to view seafloor geology from the comfort of land.

    The Samail Ophiolite (Oman–United Arab Emirates), in the northeastern corner of the Arabian Peninsula, is frequently studied as a model of obduction because of its well-exposed and well-studied geology. However, geologists disagree about the timing and geometry of the continental subduction that led to the final emplacement of the ophiolite. Several tectonic models offer hypotheses on the ophiolite’s obduction but differ in their conclusions.

    In a new study, Garber et al. [JGR: Solid Earth] sought to clarify the timing of the obduction episode in Oman. The authors sampled several different rocks from As Sifah, an Omani beach with an outcrop of high-grade continental metamorphic rocks subducted beneath the ophiolite. The studied As Sifah rocks reflect a diverse range of lithologies that all experienced the same metamorphic evolution, the authors say. Samarium-neodymium (Sm-Nd) and uranium-lead (U-Pb) radiometric dating on the garnet, zircon, and rutile crystals in the rocks helped determine the age of the subduction event.

    The findings provide new constraints on the timing of the obduction of the ophiolitic rocks in Oman. The results indicate that the episode occurred approximately 81–77 million years ago when the Arabian continental plate subducted to the northeast below the Samail Ophiolite. The subduction of the Arabian plate to mantle depths occurred at rates similar to those of other small continental subduction events, and the tectonic evolution appears to be similar to that of other ophiolite formations.

    This conclusion refutes previously published estimates that continental subduction in Oman started 110 million years ago and may have occurred over two distinct episodes. Overall, the study provides a meaningful contribution to a long-debated geologic question.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 1:55 pm on January 22, 2022 Permalink | Reply
    Tags: "Recovering Mantle Memories from River Profiles", , , Eos, , Marine fossils on mountaintops in African and Arabian deserts suggest that until about 30 million years ago those portions of the landscape were at or below sea level., , , The continent of Africa has a distinctive physical geography-an “egg carton” pattern of basins and swells-that researchers attribute to plumes of mantle rocks rising beneath a tectonic plate., The spatial and temporal evolution of this uplift process is still not well defined., The team focused on Africa; Arabia and Madagascar where regional uplift patterns are relatively well constrained during the Cenozoic period., The team used a closed-loop modeling strategy that involved inverting more than 4000 river profiles to recover signals of regional uplift., The team used dynamic forward landscape simulations to evaluate the influence of such factors as precipitation and drainage divide migration., This study suggests that calibrated inverse modeling of river profiles can be successfully used to study landscape evolution., Topography, Using the profiles of the continent’s major rivers to trace the evolution of the landscape in space and time.   

    From Eos: “Recovering Mantle Memories from River Profiles” 

    From AGU
    Eos news bloc

    From Eos

    14 January 2022
    Kate Wheeling

    1
    New research uses profiles of major rivers, like the Nile, pictured here, to trace the history of uplift across the African continent. Credit: Vaido Otsar, CC BY-SA 4.0.

    The continent of Africa has a distinctive physical geography—an “egg carton” pattern of basins and swells—that researchers attribute to plumes of mantle rocks rising beneath a tectonic plate. Marine fossils on mountaintops in African and Arabian deserts suggest that until about 30 million years ago, those portions of the landscape were at or below sea level. But the spatial and temporal evolution of this uplift process is still not well defined. In a new study, O’Malley et al. [Journal of Geophysical Research: Solid Earth] use the profiles of the continent’s major rivers to trace the evolution of the landscape in space and time.

    To test the idea that rivers might serve as “tape recorders” for mantle processes, the team focused on Africa, Arabia, and Madagascar, where regional uplift patterns are relatively well constrained during the Cenozoic period. They applied a closed-loop modeling strategy that involved inverting more than 4,000 river profiles to recover signals of regional uplift and validating those signals with geological observations.

    The team used dynamic forward landscape simulations to evaluate the influence of such factors as precipitation and drainage divide migration, as well as to test the assumptions used in the inverse modeling of river profiles. Although these assumptions are still a matter of debate, this study showed that inverse modeling of river profiles across the study area recovers an uplift history that fits observations, and landscape simulations using these uplift histories predict drainage networks, paleotopography, and deltaic sedimentation histories that match data. This result remains true when precipitation rates vary across space and time. Overall, this study suggests that calibrated inverse modeling of river profiles can be successfully used to study landscape evolution.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 1:17 pm on January 22, 2022 Permalink | Reply
    Tags: "Understanding Rare Rain Events in the Driest Desert on Earth", Additional research is needed to confidently show that the Amazon is the source of the moisture brought by some of the conveyor belts., , , , Eos, It’s like a decade worth of rain within one single event within a couple hours., , Moisture conveyor belts, Moisture conveyor belts occur throughout the nearby Andes region about 4 times per year., Most of the moisture originates in the Amazon basin-a surprising result given the high Andes that divide the rain forest from the desert., ,   

    From Eos: “Understanding Rare Rain Events in the Driest Desert on Earth” 

    From AGU
    Eos news bloc

    From Eos

    18 January 2022
    Emily Cerf

    A new study reveals the atmospheric paths of storm events that can deliver a decade’s worth of rain in a few hours to the Atacama Desert.

    1
    Parts of the Atacama Desert receive fewer than 5 millimeters of rainfall a year. Credit: Wescottm, CC BY 4.0.

    In the enduring dryness of the Atacama Desert in northern Chile where the average rainfall is as low as 5 millimeters per year, rare rain events can come swiftly and intensely. They shape the landscape and provide precious moisture to plants and other species that otherwise adapted to extended dry spells or harvesting coastal fog. Intense rain events like those seen in the Atacama are known to be associated with so-called ‘moisture conveyor belts”, which are high-altitude atmospheric phenomena known for transporting large volumes of water vapor. However, whether or not “moisture conveyor belts” are responsible for the Atacama’s intense rain events has yet to be shown.

    In a new study, Böhm et al.[Geophysical Research Letters] explain the atmospheric mechanisms behind the wettest of these precipitation events and propose that the water travels from the tropical Amazon across oceans and mountains to reach the desert. The research shows that 40%–80% of the total precipitation that occurs between the coast and the Andean foothills is associated with “moisture conveyor belts”.

    Rain events related to “moisture conveyor belts” can be devastating for local microbial species adapted to dry conditions, the authors say, but they could play a role in the germination of the blooming desert—an explosion of colorful wildflowers that occurs in the Atacama every 5 to 7 years. The authors’ understanding of the processes behind these rare events could change how scientists understand past and future climates in the region.

    Cataloging Conveyor Belts

    Böhm and colleagues cataloged the role of the conveyor belts in the Atacama for the first time. To figure out the role of “moisture conveyor belts” and track air masses, the researchers examined a 2017 precipitation event that brought more than 50 millimeters of rain to some regions of the Atacama. Modeling that tracked the paths of the air masses suggested that most of the moisture originated in the Amazon basin, a surprising result given the high Andes that divide the rain forest from the desert. The authors also discovered that “moisture conveyor belts” occur throughout the nearby Andes region about 4 times per year—some don’t bring much precipitation at all, but the wettest of them can be extreme.

    “It’s like a decade worth of rain within one single event within a couple hours,” said Christoph Böhm, lead author of the study from the Institute for Geophysics and Meteorology at The University of Cologne [Universität zu Köln](DE). Ten times the annual precipitation can be rained down by these conveyor belts in the midsection of Earth’s lowest atmospheric layer, the troposphere.

    In tracing how water moves in moisture conveyor belts across the continent, the researchers suggest that in the most humid of these extreme events, the moisture originates in the tropical Amazon basin rather than over the Pacific Ocean that lies west of the desert.

    However, additional research is needed to confidently show that the Amazon is the source of the moisture brought by some of the conveyor belts. An examination of isotopic data—the atomic chemical information of the water—from the rain events is necessary to support this idea, according to Cornell University (US) geologist Teresa Eileen Jordan, who studies the Atacama and was not involved in the research. The hypothetical path of the water from the Amazon over the Andes would fundamentally change the chemical composition of the water, she says.

    New ideas about how water is transported to these regions can shape how paleoclimatologists understand past eras in this region, affecting understandings of past civilizations that may also have depended on these processes, and can inform water resource management and predictions of future climate change in the Atacama Desert.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 7:16 pm on January 15, 2022 Permalink | Reply
    Tags: "Invasive Plants and Climate Change Will Alter Desert Landscapes", , , , , Eos, Invasive buffelgrass weathers higher temperatures and drought conditions better than its native brethren.,   

    From The University of Arizona (US) via Eos : “Invasive Plants and Climate Change Will Alter Desert Landscapes” 

    From The University of Arizona (US)

    via

    AGU
    Eos news bloc

    Eos

    13 January 2022
    Katherine Kornei

    In experiments conducted in Biosphere 2 at The University of Arizona (US), invasive buffelgrass weathers higher temperatures and drought conditions better than its native brethren.

    1
    In Arizona’s Saguaro National Park, volunteers remove buffelgrass, an invasive species, from the desert ecosystem. Credit: National Park Service (US).

    The towering saguaro cactus may be the icon of the American Southwest, but an invasive plant is steadily encroaching into desert ecosystems. The interloper, a knee-high species of grass known as buffelgrass, will likely become even more of a presence in arid landscapes in the future, new research has revealed. That’s because buffelgrass weathers increased temperatures and drought conditions—two hallmarks of climate change—more readily than its native brethren. According to the researchers, arid environments are slated to experience pronounced changes in vegetation in the coming decades, a shift that will have far-reaching implications not only for desert ecosystems themselves but also for human-built infrastructures.

    Guaranteed from the Start

    Buffelgrass (Pennisetum ciliare) was first introduced to North America from Africa in the 1930s. The tough grass was originally intended as food for foraging cattle. Like other plants such as kudzu that have thrived in their nonnative environments, buffelgrass’s biological success was just about guaranteed from the start: Its seedlings survive at high rates, it can rapidly colonize bare soil, it makes efficient use of water, and it’s capable of tolerating extreme drought.

    Today buffelgrass is a common sight in the vast Sonoran Desert, which spans the southwestern United States and northwestern Mexico. But it’s an unwelcome guest—buffelgrass has been labeled a “noxious weed” by the Arizona Department of Agriculture, and the National Park Service regularly hosts “buffelgrass pulls.”

    “It invades deserts and crowds out native plants,” said Perry Grissom, a restoration ecologist at Saguaro National Park in Tucson who was not involved in the research and who has led many buffelgrass pulls. “It’s better adapted to our desert than our plants that are endemic.”

    Biodiversity to Monoculture

    Buffelgrass’s bad reputation is well earned, said Sujith Ravi, an environmental scientist at Temple University (US), lead author of the study. It slashes ecosystem biodiversity by outcompeting native grasses, leading to landscapes that are veritable monocultures, he said. “Whereas there used to be a mixture of different communities, now it’s more of a single-community landscape.”

    That’s bad news, because biodiversity has been shown to make ecosystems more stable and resilient to potentially adverse changes. And when an inevitable “crash” occurs—when essentially all vegetation dies off for a period of time—the soil that’s exposed is readily eroded by wind and water. “There’s an irreversible loss of resources from the system,” explained Ravi. Furthermore, when buffelgrass thrives, the thick vegetation facilitates the spread of fire in an otherwise patchy landscape, and larger fires are more likely to affect human-built infrastructure.

    With climate models predicting increasing temperatures and more frequent droughts in arid landscapes, an open question is how well buffelgrass will fare in the future compared with native plants. Several years ago, Ravi and his colleagues began an experimental investigation of buffelgrass and its native counterpart, tanglehead (Heteropogon contortus), in the glass-walled Biosphere 2 research facility in southern Arizona.

    A Harbinger of the Future

    Biosphere 2 is an ideal laboratory for studying the effects of climate change because it can be tuned to create different environmental conditions. The facility, which tops 3 acres, reproduces several of the planet’s major biomes—including the ocean, wetlands, rain forest, savannah, and desert. “It’s like a field experiment because it’s so huge,” said Ravi.

    The team grew hundreds of buffelgrass and tanglehead plants and divided them between Biosphere 2’s savannah biome, maintained at ambient conditions, and its desert biome, which is warmed by roughly 5°C. The idea was to repeat the experiments in two conditions to mimic the effects of climate change, said Ravi.

    After watering the plants regularly for a few months, the researchers then withheld irrigation from half of the plants for several months, effectively exposing them to drought-like conditions. The water-starved grasses responded as they would in nature: They went dormant. The team accordingly irrigated the plants again the following spring before finally quantifying what fraction of grasses of each species, exposed to each set of temperature and moisture conditions, survived.

    Ravi and his colleagues found that grasses of both species rallied after experiencing drought-like conditions at ambient temperatures. But the combination of warmer temperatures and lack of moisture killed 100% of the native tanglehead plants compared with only roughly 80% of the invasive buffelgrass plants. That’s a significant difference in mortality, said Ravi. “If something is going to come back, it’s going to be the invasive grass.”

    This finding wasn’t wholly unexpected given the nature of buffelgrass, said Grissom. “After seeing how it behaves, I’m not surprised. It’s really tough.”

    These results are a harbinger of what’s to come in arid regions, the researchers suggested. Drought- and heat-adapted invasive plants like buffelgrass will increasingly gain a toehold, at the expense of native species. Climate change and biological invasions work in tandem to alter desert landscapes for the worse, said Ravi. “They can synergistically act to drive landscapes into degradation.”

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

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

    As of 2019, the The University of Arizona (US) enrolled 45,918 students in 19 separate colleges/schools, including The University of Arizona College of Medicine in Tucson and Phoenix and the James E. Rogers College of Law, and is affiliated with two academic medical centers (Banner – University Medical Center Tucson and Banner – University Medical Center Phoenix). The University of Arizona is one of three universities governed by the Arizona Board of Regents. The university is part of the Association of American Universities and is the only member from Arizona, and also part of the Universities Research Association(US). The university is classified among “R1: Doctoral Universities – Very High Research Activity”.

    Known as the Arizona Wildcats (often shortened to “Cats”), The University of Arizona’s intercollegiate athletic teams are members of the Pac-12 Conference of the NCAA. The University of Arizona athletes have won national titles in several sports, most notably men’s basketball, baseball, and softball. The official colors of the university and its athletic teams are cardinal red and navy blue.

    After the passage of the Morrill Land-Grant Act of 1862, the push for a university in Arizona grew. The Arizona Territory’s “Thieving Thirteenth” Legislature approved The University of Arizona in 1885 and selected the city of Tucson to receive the appropriation to build the university. Tucson hoped to receive the appropriation for the territory’s mental hospital, which carried a $100,000 allocation instead of the $25,000 allotted to the territory’s only university (Arizona State University(US) was also chartered in 1885, but it was created as Arizona’s normal school, and not a university). Flooding on the Salt River delayed Tucson’s legislators, and by they time they reached Prescott, back-room deals allocating the most desirable territorial institutions had been made. Tucson was largely disappointed with receiving what was viewed as an inferior prize.

    With no parties willing to provide land for the new institution, the citizens of Tucson prepared to return the money to the Territorial Legislature until two gamblers and a saloon keeper decided to donate the land to build the school. Construction of Old Main, the first building on campus, began on October 27, 1887, and classes met for the first time in 1891 with 32 students in Old Main, which is still in use today. Because there were no high schools in Arizona Territory, the university maintained separate preparatory classes for the first 23 years of operation.

    Research

    The University of Arizona is classified among “R1: Doctoral Universities – Very high research activity”. UArizona is the fourth most awarded public university by National Aeronautics and Space Administration(US) for research. The University of Arizona was awarded over $325 million for its Lunar and Planetary Laboratory (LPL) to lead NASA’s 2007–08 mission to Mars to explore the Martian Arctic, and $800 million for its OSIRIS-REx mission, the first in U.S. history to sample an asteroid.

    The LPL’s work in the Cassini spacecraft orbit around Saturn is larger than any other university globally. The University of Arizona laboratory designed and operated the atmospheric radiation investigations and imaging on the probe. The University of Arizona operates the HiRISE camera, a part of the Mars Reconnaissance Orbiter. While using the HiRISE camera in 2011, University of Arizona alumnus Lujendra Ojha and his team discovered proof of liquid water on the surface of Mars—a discovery confirmed by NASA in 2015. The University of Arizona receives more NASA grants annually than the next nine top NASA/JPL-Caltech(US)-funded universities combined. As of March 2016, The University of Arizona’s Lunar and Planetary Laboratory is actively involved in ten spacecraft missions: Cassini VIMS; Grail; the HiRISE camera orbiting Mars; the Juno mission orbiting Jupiter; Lunar Reconnaissance Orbiter (LRO); Maven, which will explore Mars’ upper atmosphere and interactions with the sun; Solar Probe Plus, a historic mission into the Sun’s atmosphere for the first time; Rosetta’s VIRTIS; WISE; and OSIRIS-REx, the first U.S. sample-return mission to a near-earth asteroid, which launched on September 8, 2016.

    The University of Arizona students have been selected as Truman, Rhodes, Goldwater, and Fulbright Scholars. According to The Chronicle of Higher Education, UArizona is among the top 25 producers of Fulbright awards in the U.S.

    The University of Arizona is a member of the Association of Universities for Research in Astronomy(US), a consortium of institutions pursuing research in astronomy. The association operates observatories and telescopes, notably Kitt Peak National Observatory(US) just outside Tucson. Led by Roger Angel, researchers in the Steward Observatory Mirror Lab at The University of Arizona are working in concert to build the world’s most advanced telescope. Known as the Giant Magellan Telescope(CL), it will produce images 10 times sharper than those from the Earth-orbiting Hubble Telescope.

    GMT Giant Magellan Telescope(CL) 21 meters, to be at the Carnegie Institution for Science’s(US) NOIRLab(US) NOAO(US) Las Campanas Observatory(CL), some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high.

    The telescope is set to be completed in 2021. GMT will ultimately cost $1 billion. Researchers from at least nine institutions are working to secure the funding for the project. The telescope will include seven 18-ton mirrors capable of providing clear images of volcanoes and riverbeds on Mars and mountains on the moon at a rate 40 times faster than the world’s current large telescopes. The mirrors of the Giant Magellan Telescope will be built at The University of Arizona and transported to a permanent mountaintop site in the Chilean Andes where the telescope will be constructed.

    Reaching Mars in March 2006, the Mars Reconnaissance Orbiter contained the HiRISE camera, with Principal Investigator Alfred McEwen as the lead on the project. This National Aeronautics and Space Agency (US) mission to Mars carrying the UArizona-designed camera is capturing the highest-resolution images of the planet ever seen. The journey of the orbiter was 300 million miles. In August 2007, The University of Arizona, under the charge of Scientist Peter Smith, led the Phoenix Mars Mission, the first mission completely controlled by a university. Reaching the planet’s surface in May 2008, the mission’s purpose was to improve knowledge of the Martian Arctic. The Arizona Radio Observatory(US), a part of The University of Arizona Department of Astronomy Steward Observatory(US), operates the Submillimeter Telescope on Mount Graham.

    The National Science Foundation(US) funded the iPlant Collaborative in 2008 with a $50 million grant. In 2013, iPlant Collaborative received a $50 million renewal grant. Rebranded in late 2015 as “CyVerse”, the collaborative cloud-based data management platform is moving beyond life sciences to provide cloud-computing access across all scientific disciplines.

    In June 2011, the university announced it would assume full ownership of the Biosphere 2 scientific research facility in Oracle, Arizona, north of Tucson, effective July 1. Biosphere 2 was constructed by private developers (funded mainly by Texas businessman and philanthropist Ed Bass) with its first closed system experiment commencing in 1991. The university had been the official management partner of the facility for research purposes since 2007.

    U Arizona mirror lab-Where else in the world can you find an astronomical observatory mirror lab under a football stadium?

    University of Arizona’s Biosphere 2, located in the Sonoran desert. An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why The University of Arizona is a university unlike any other.

    University of Arizona Landscape Evolution Observatory at Biosphere 2.

     
  • richardmitnick 2:09 pm on January 14, 2022 Permalink | Reply
    Tags: "Hydrothermal Microbes Can Be Green Energy Producers", , At deep-sea vents near the Mariana Arc highly concentrated slurries of minerals are released from the vents; mix with seawater and encourage the growth of microbes., Eos, , Organic compounds can form from inorganic materials releasing energy along the way., The reducing environment can support organisms that actually release energy when they form.   

    From Eos: “Hydrothermal Microbes Can Be Green Energy Producers” 

    From AGU
    Eos news bloc

    From Eos

    7 January 2022
    Sarah Derouin

    In ultramafic, reducing environments, forming microbial proteins can actually release energy.

    1
    At deep-sea vents like this one in the western Pacific near the Mariana Arc, highly concentrated slurries of minerals are released from the vents, mix with seawater, and encourage the growth of microbes. In some cases, the reducing environment can support organisms that actually release energy when they form, instead of requiring it. Credit: Pacific Ring of Fire 2004 Expedition,The National Oceanic and Atmospheric Administration (US) Office of Ocean Exploration; Dr. Bob Embley, Chief Scientist The National Oceanic and Atmospheric Administration (US) NOAA Pacific Marine Environmental Laboratory (PMEL).CC BY 2.0.

    The deep-sea neighborhoods around hydrothermal hot spots are a party of productivity, especially compared to the majority of the seafloor. The heat, minerals, dissolved gases, and pressures found in these hot spots provide rich environments in which microbial communities can thrive.

    In these harsh conditions with swirling chemicals, organic compounds can form from inorganic materials, releasing energy along the way, which is the opposite of more familiar conditions on Earth’s surface, in which energy is consumed to form organic materials. Bacteria gain energy by reducing carbon dioxide with hydrogen to make methane and water—a process called autotrophic methanogenesis.

    In a new study by Dick and Shock, the researchers looked into where else energy might be released in ultramafic, hydrothermal ecosystems and what that might mean for life in these complex biogeochemical environments. They looked at hydrothermal vents in the Mid-Atlantic Ridge (the vent field called Rainbow that is hosted in ultramafic rocks) and a vent on the Juan de Fuca boundary in the Pacific (a basalt-hosted vent field called Endeavour).

    2
    The Mid-Atlantic Ridge. Credit: NOAA.

    3
    Subduction of the Juan de Fuca Plate beneath the North American Plate. Credit: Geological Survey (US)

    The researchers looked at nearly 1,800 proteins for Methanocaldococcus jannaschii, a member of the Archaea found in hydrothermal vents, and parsed out autotrophic methanogenesis reactions and overall amino acid synthesis reactions in both vent locations.

    They found that methanogenesis was driven by the large disequilibrium of chemicals that result from the mixing of hydrothermal fluids and seawater. The team discovered that in ultramafic systems, energy is released in protein synthesis over a wide range of temperatures. However, the same was not found for basalt-hosted vents, where temperature ranges were smaller for methanogenesis and protein synthesis doesn’t release energy.

    Considering these findings, the researchers note that particular hydrothermal systems are hot spots for microbial proliferation. They note that in highly reduced systems, the way proteins are synthesized and energy is released can tell researchers much about how biogeochemical cycles could have driven the emergence of life in the deep sea.

    Science paper:
    Journal of Geophysical Research: Biogeosciences

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 1:21 pm on January 14, 2022 Permalink | Reply
    Tags: "The Uncertain Future of Antarctica’s Melting Ice", , , , Eos, ,   

    From Eos: “The Uncertain Future of Antarctica’s Melting Ice” 

    From AGU
    Eos news bloc

    From Eos

    10 January 2022
    Florence Colleoni
    Tim Naish
    Robert DeConto
    Laura De Santis
    Pippa L. Whitehouse

    A new multidisciplinary, international research program aims to tackle one of the grand challenges in climate science: resolving the Antarctic Ice Sheet’s contribution to future sea level rise.

    1
    Meltwater pours from a 130-meter-wide waterfall over the edge of the Nansen ice shelf in Antarctica on 12 January 2014. Credit: Won Sang Lee, Korea Polar Research Institute [목록 > > 극지연구소(영문)](KR)

    Among the most visible effects of anthropogenic global warming are rising seas around the world: Since 1880, the global mean sea level (GMSL) has increased by 20 centimeters. There’s no easy way to halt or reverse this change. Earth’s ocean and ice sheets respond slowly to changes in the heat they receive from the atmosphere, and they hold onto heat for decades to centuries. As a result, sea level globally will continue to rise well beyond the 21st century, even if warming of the planet is stabilized below the target set by the Paris climate agreement in 2015 of 2°C above the preindustrial average.

    The recent Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) and the 2019 revision of the World Population Prospects both state that it is very likely that climate change–induced sea level rise will affect much of the world’s coasts in the coming decades. An estimated 800 million people are likely to experience impacts of high-tide flooding by the end of the 21st century, even if the Paris climate agreement target is met.

    In many coastal settings, even a small increase in baseline sea level can substantially increase the frequency and magnitude of flooding during high tides, storm surges, and extreme weather. The United Nations estimates that the potential costs of damage to harbors and ports alone from this flooding could be as high as $111.6 billion by 2050 and $367.2 billion by the end of the century.

    What’s more, if policies aimed at curtailing greenhouse gas emissions and atmospheric warming this century fail, sea level rise will accelerate, dramatically reshaping our shorelines for centuries to come. Higher seas will cause shorelines to recede and coastal flooding to worsen impacts on communities, infrastructure, natural resources, and biodiversity on all the world’s coastlines. It is already unavoidable that many communities will be displaced and, in some cases, forced to migrate as climate refugees.

    Quantifying the pace of GMSL rise as well as the magnitude of the long-term rise (a few centuries onward), to which we are committed, is thus essential for effective adaptation planning and the evaluation of mitigation pathways and policies. Pinning down these quantities requires a focused effort from the scientific community to identify and understand the key rate-determining processes that affect melting of the Antarctic Ice Sheet (AIS)—the largest and most uncertain potential contributor to future sea level rise.

    Many of these processes generate dynamical instabilities and involve nonlinear and potentially irreversible behaviors. Thus, establishing their relative roles in future ice sheet dynamics will not only improve sea level projections but may identify a threshold level of atmospheric carbon dioxide that once crossed, may cause unstoppable, multigenerational mass loss from the AIS and commitment to global sea level rise.

    In February 2021, Instabilities and Thresholds in Antarctica (INSTANT), an international, interdisciplinary, and interorganizational program of the Scientific Committee on Antarctic Research (SCAR), was launched with the specific goal of reducing these uncertainties and filling gaps in our knowledge of the AIS.

    Disappearing Ice Shelves

    About a third of the AIS is marine based, resting on bedrock below sea level, and most of the ice sheet margin terminates in the ocean, making it susceptible to dynamical instabilities that can cause rapid ice loss [Pattyn and Morlighem, 2020*].

    *All included citations are included in “References” below.

    In many places around the ice sheet margin, the seaward-flowing ice forms floating ice shelves. Ice shelves in contact with bathymetric highs in the seafloor or confined within embayments provide buttressing that impedes the flow of upstream ice. Disintegration of ice shelves will therefore play a key role in the pace of future ice mass loss. Satellite observations show that most Antarctic ice shelves are currently thinning, primarily because of contact with warm subsurface ocean water [Adusumilli et al., 2020].

    2
    The edge of the Ronne Ice Shelf floats in the Weddell Sea off Antarctica. Disintegration of ice shelves, which provide buttressing that impedes the flow of upstream ice, will play a key role in the pace of future ice mass loss from Antarctica. Credit: Ricarda Winkelmann (distributed via imaggeo.egu.eu), CC BY-NC-ND 3.0.

    In the future, ice shelves could also become vulnerable to atmospheric warming and to the accumulation of surface meltwater, which can deepen crevasses and lead to sudden breakup through hydrofracturing. If the grounding line (the boundary between grounded and floating ice) is located on bedrock sloping down toward the ice sheet interior, the initial retreat caused by thinning ice shelves could result in a self-sustaining and potentially unstoppable process of retreat known as marine ice sheet instability (MISI).

    Alternatively, disappearing ice shelves may lead to the formation of tall, unstable ice cliffs at the grounding line. Calving from these ice cliffs may then cause rapid ice sheet retreat by a process called marine ice cliff instability (MICI). It is possible that both types of instabilities could cause partial collapse of marine-based sectors of the AIS within a few centuries [DeConto et al., 2021].

    Uncertain Outcomes of Complex Processes

    In addition to the effects of marine ice sheet and ice cliff instabilities, the rates of AIS mass loss and GMSL rise will be affected by complex interactions among ice, ocean, atmosphere, and solid Earth processes. These interactions involve both positive and negative feedbacks that amplify and reduce the rate of GMSL rise, respectively. For example, fresh water released as ice sheets thin and retreat reduces the formation of salty, dense Antarctic bottom water. Reductions in Antarctic bottom water weaken global thermohaline circulation, which is driven by differences in water temperature and salinity, leading to local and interhemispheric atmospheric cooling [Golledge et al., 2019]. These reductions could ultimately reduce the pace of global warming and thus slow sea level rise [Golledge et al., 2019; DeConto et al., 2021].

    However, fresh water released from ice sheets stratifies the surface ocean and subsequently enhances sea ice production, which disrupts the opening of sea ice–free areas called polynyas [e.g., Golledge et al., 2019], thus limiting gas and heat exchange between the atmosphere and the ocean. This sequence of feedbacks may focus warm seawater into cavities near grounding zones below ice shelves, increasing rates of ice loss [Silvano et al., 2018]

    Critical steps to reduce uncertainties in the role of these processes and in projections of Antarctic ice loss involve elucidating the role of ocean dynamics by reconstructing deep- to near-past conditions, by observing present conditions, and by coupling numerical ocean circulation models to ice sheet models. These steps were among the most urgent research priorities to emerge from the IPCC Fifth Assessment Report (AR5), published in 2013, which predicted that the “likely” range of future carbon emission scenarios envisioned at the time would result in 28–98 centimeters of GMSL rise by 2100.

    However, the AR5 estimates were limited by a lack of scientific understanding of key processes affecting dynamic loss of the AIS. Since then, the incorporation of instabilities such as MICI and MISI into numerical ice sheet models has resulted in a low-probability, high-impact future sea level rise scenario included in the recently released IPCC AR6, in which GMSL rise of up to 2 meters by 2100 “could not be ruled out” (Figure 1).

    In general, the latest generation of numerical ice sheet models shows that the acceleration in mass loss observed by satellites over the past 10 years will continue [IMBIE team, 2018], although different models show a wide range of projections for Antarctica’s future contribution to GMSL rise because they treat the physics of potentially important processes in considerably different ways [e.g., Edwards et al., 2021] (Figure 1).

    If global carbon emissions follow the high-emission Shared Socioeconomic Pathway (SSP) 5–8.5, meaning atmospheric carbon dioxide levels rise above 1,000 parts per million by 2100 (Figure 1), melting Antarctic ice would contribute 14–32 centimeters (13th–87th percentiles) to an overall GMSL rise of 62–101 centimeters (relative to the 1995–2014 baseline) over the same period, according to a statistical assessment of numerical model projections [e.g., Edwards et al., 2021].

    3
    Fig. 1. The evolution of atmospheric carbon dioxide (CO2) concentration (in parts per million, ppm) observed at Mauna Loa Observatory in Hawaii from about 1960 until 2020 (smooth black curve) is shown (top), along with projected CO2 concentrations (rippled gray curves) for various Shared Socioeconomic Pathways (SSPs) until 2100. Years when key U.N. Framework Convention on Climate Change Conferences of Parties (COPs) were held are shown together with the IPCC Assessment Report publication years. Observed (brown) global mean sea level change (GMSL) from 1950 to 2020 [Frederikse et al., 2020] is shown (bottom) relative to the 1994–2015 baseline, along with projected changes for SSP 1–2.6 (blue) and SSP 5–8.5 (orange) and the 83rd percentile for the low-confidence SSP 5–8.5 (dashed red line) from IPCC AR6. The uncertainties indicated correspond to the 17th and 83rd percentiles for each SSP. Rates of sea level change (in millimeters/year) for SSP 8.5 until 2100 are also shown. The projected ranges (17th to 83rd percentiles) of GMSL change and the Antarctic contribution until 2300 CE (extended scenarios) from IPCC AR6 are plotted (right) for SSP 1–2.6 (blue) and SSP 5–8.5 (orange) pathways and for the 83rd percentile of the low-confidence scenario SSP 5–8.5 (dashed red arrows, accounting for instability processes in Antarctic ice sheet projections).

    Another single model that accounts for both MICI and MISI produced a higher estimate of 20–53 centimeters (13th–87th percentiles) for the likely range of the Antarctic contribution to GMSL rise by 2100 for the SSP 5–8.5 scenario [DeConto et al., 2021]. Moreover, under this model scenario, marine-based sectors of the AIS cross a tipping point of runaway ice loss before 2100, committing the planet to sea level rise of as much as 2 meters by 2100 and 15 meters by 2300 [Golledge et al., 2015; DeConto et al., 2021].

    If, however, the global emissions trajectory follows the lower-emission scenario SSP 1–2.6 (Figure 1), which is consistent with the emission target set by the Paris climate agreement, then the Antarctic contribution will likely be significantly lower: 12–31 centimeters by 2100 [Edwards et al., 2021] and about 100 centimeters by 2300 [DeConto et al., 2021]. Under this scenario, models indicate that most of the Antarctic ice shelves would be preserved even on multicentury timescales, substantially limiting ice loss to the ocean [Golledge et al., 2015; DeConto et al., 2021].

    A GMSL rise of about 25 centimeters by 2060 may be unavoidable. But notwithstanding results from our most sophisticated models to date, our poor understanding of key melt rate–determining processes and our uncertain emission trajectory create deep uncertainty in probabilistic sea level projections beyond the mid-21st century [e.g., Edwards et al., 2021; DeConto et al., 2021], impeding efforts to plan for impending changes along shorelines. This uncertainty suggests, for example, that there is a 5% chance that the Antarctic contribution to GMSL rise could be as much as 145 centimeters by 2100 [Bamber et al., 2019].

    A further complication to understanding Antarctic contributions to sea level rise is that melting ice sheets do not cause globally uniform changes. When melting ice flows into the ocean, it changes Earth’s gravitational field and rotational state, thus redistributing water in the ocean; in addition, the remaining ice exerts less pressure on the land below, causing the land to rise. This viscoelastic response of the solid Earth to ice loss, a process known as glacial isostatic adjustment, means that locations near a melting ice sheet experience less sea level rise than more distant locations, with deviations of up to 30% of the global mean.

    Crucially, these processes also feed back into ice sheet dynamics [Whitehouse et al., 2019]. Unlike most feedbacks affecting ice sheets, which amplify mass loss, glacial isostatic adjustment might help stabilize a retreating ice margin by creating subglacial pinning points on the seafloor. Understanding how glacial isostatic adjustment influences Antarctic ice sheet dynamics and how they affect patterns of regional sea level change are critical areas of inquiry for improving site-specific sea level projections.

    An INSTANT Solution to Tackle Uncertainty

    To advance understanding of processes affecting ice melting and reduce the deep uncertainty in Antarctica’s contribution to past and future sea level change, SCAR, an international coordinating body for Antarctic science, launched the INSTANT program. The initiative is following a multidisciplinary Earth system approach combining studies of geology, geophysics, atmosphere and ocean sciences, and glaciology to investigate long-term to short-term interactions among the ocean, atmosphere, solid Earth, and AIS.

    INSTANT will build upon high-impact research and networking capacity developed within previous SCAR strategic research programs, including Past Antarctic Ice Sheet dynamics, Solid Earth Responses and Influence on Cryospheric Evolution, and Antarctic Climate in the 21st Century. These programs began addressing a key priority that arose out of IPCC AR5 and is one of six priorities identified in SCAR’s first Antarctic and Southern Ocean Science Horizon Scan: to better understand how, where, and why ice sheets lose mass. Seven years on from when the Horizon Scan was concluded, great progress has been made on this priority [Florindo et al., 2021]. But because of the long lead times needed to acquire critical field observations that help us better understand physical processes and to incorporate these observations into next-generation numerical models to improve projections, the most important work lies ahead in the coming decade.

    The ambitious goals of INSTANT and its partner organizations (e.g., the World Climate Research Programme) call for large-scale scientific cooperation over the next 8 years focused on three main themes:

    -improving understanding of atmospheric and ocean forcing on ice sheet dynamics.
    -elucidating how solid Earth processes and traits, such as glacial isostatic adjustment and the roughness and depth of the subglacial bedrock, affect ice sheet dynamics and regional to global nonuniform sea level change.
    -integrating new scientific results to improve reconstructions and predictions of the AIS contribution to sea level change and communicating and applying these projections beyond the research community.

    Engaging Scientists and Stakeholders

    INSTANT’s leadership is international and includes researchers from a range of career stages. Overall, the program already has more than 200 members from more than 40 different countries. The program will facilitate knowledge sharing and build synergic efforts to carry on multiple campaigns among these members by fostering multidisciplinary international research collaborations as well as by organizing workshops, publications, and training schools.

    This collective approach will provide opportunities to bridge existing professional networks, increase the use of data banks, and spark new ideas and collaborations among scientists in different communities, such as those collecting observational data and those developing predictive models, to address technical challenges and push scientific frontiers. With its demographic diversity, as well as the diversity of science it will facilitate, INSTANT also provides an ideal framework to train a new generation of Earth scientists capable of informing pressing societal needs to better anticipate and manage future sea level rise.

    Scientific outcomes from INSTANT—especially updated and more accurate projections of the rates, magnitudes, uncertainties, and likely impacts of Antarctica’s contribution to global sea level rise—will be important to a wide range of stakeholder groups. Crucially, as emphasized in its science and implementation plan, INSTANT will bridge this science with efforts to craft policy related to sea level change and to assess the potential effectiveness of, and risks associated with, climate change mitigation pathways and adaptation options. This effort will involve communication to and engagement with Earth system scientists, social scientists, practitioners, decisionmakers, planners, and the public.

    The outcomes of this communication and engagement will help guide adaptation approaches around the world to avoid the worst impacts of sea level rise as shorelines shift and communities, infrastructure, and ecosystems are inundated.

    References:

    Adusumilli, S., et al. (2020), Interannual variations in meltwater input to the Southern Ocean from Antarctic ice shelves, Nat. Geosci., 13, 616–620, https://doi.org/10.1038/s41561-020-0616-z.

    Bamber, J. L., et al. (2019), Ice sheet contributions to future sea-level rise from structured expert judgment, Proc. Natl. Acad. Sci., 116(23), 11,195–11, 200, https://doi.org/10.1073/pnas.1817205116.

    DeConto, R. M., et al. (2021), The Paris climate agreement and future sea-level rise from Antarctica, Nature, 593(7857), 83–89, https://doi.org/10.1038/s41586-021-03427-0.

    Edwards, T. L., et al. (2021), Projected land ice contributions to twenty-first-century sea level rise, Nature, 593(7857), 74–82, https://doi.org/10.1038/s41586-021-03302-y.

    Florindo, F., et al. (Eds.) (2021), Antarctic Climate Evolution, 2nd ed., Elsevier, Amsterdam.

    Frederikse, T., et al. (2020), The causes of sea-level rise since 1900, Nature, 584(7821), 393–397, https://doi.org/10.1038/s41586-020-2591-3.

    Golledge, N. R., et al. (2015), The multi-millennial Antarctic commitment to future sea-level rise, Nature, 526(7573), 421–425, https://doi.org/10.1038/nature15706.

    Golledge, N. R., et al. (2019), Global environmental consequences of twenty-first-century ice-sheet melt, Nature, 566(7742), 65–72, https://doi.org/10.1038/s41586-019-0889-9.

    IMBIE team (2018), Mass balance of the Antarctic Ice Sheet from 1992 to 2017, Nature, 558(7709), 219–222, https://doi.org/10.1038/s41586-018-0179-y.

    Pattyn, F., and M. Morlighem (2020), The uncertain future of the Antarctic Ice Sheet, Science, 367(6484), 1,331–1,335, https://doi.org/10.1126/science.aaz5487.

    Silvano, A., et al. (2018), Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic bottom water, Science Adv., 4(4), eaap9467, https://doi.org/10.1126/sciadv.aap9467.

    Whitehouse, P. L., et al. (2019), Solid Earth change and the evolution of the Antarctic Ice Sheet, Nature Commun., 10(1), 1–14, https://doi.org/10.1038/s41467-018-08068-y.

    See the full article here .

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  • richardmitnick 2:20 pm on January 7, 2022 Permalink | Reply
    Tags: "Sensing Iceland’s Most Active Volcano with a 'Buried Hair' ", 1932, and 1922)., , Ash clouds can also cause major shutdowns and economic damage in the air traffic industry as happened during the 2010 eruption of Eyjafjallajökull located about 140 kilometers southwest of Grímsvöt, Ash clouds pose threats to humans and livestock when direct interaction between magma and meltwater causes Grímsvötn to erupt explosively., Conducting a large-scale field experiment in the middle of 7900-square-kilometer Vatnajökull was challenging., , Eos, Fiber-optic cable was the core component of the experiment., , Grímsvötn has been the island’s most active volcano—and it may be due for another major eruption., Grímsvötn is a complex volcanic system that is governed by both geothermal heat from below and the ice of the overlying glacier., Grímur’s lakes-Grímsvötn in Icelandic-continue to spit fire even as they are buried under hundreds of meters of the ice of Europe’s largest glacier Vatnajökull., In addition to the flood hazard, Jökulhlaups: major outburst floods of a subglacial lake within the caldera of the volcano., Past jökulhlaups from Grímsvötn have destroyed bridges and cut off transit between western and eastern Iceland., Rapid and substantial pressure decreases-such as that seen beginning in late November-have previously caused Grímsvötn to erupt (in 2004, The scientists laid out 12 kilometers of fiber-optic cable in a hook-shaped pattern along much of the caldera rim and atop the subglacial lake (Figure 1)., The scientists trenched the cable 50 centimeters deep into the snow thereby protecting it from atmospheric influences.,   

    From Eos: “Sensing Iceland’s Most Active Volcano with a ‘Buried Hair’ “ 

    From AGU
    Eos news bloc

    From Eos

    4 January 2022
    Sara Klaasen
    Sölvi Thrastarson
    Andreas Fichtner
    Yeşim Çubuk-Sabuncu
    Kristín Jónsdóttir

    Distributed acoustic sensing offered researchers a means to measure ground deformation from atop ice-clad Grímsvötn volcano with unprecedented spatial and temporal resolutions.

    1
    A snowcat plows its way through snow near the caldera rim of Grímsvötn volcano in Iceland in spring 2021 during the deployment of a fiber-optic cable for distributed acoustic sensing (DAS). Credit: Yeşim Çubuk-Sabuncu.

    2
    Fig. 1. This map of Grímsvötn shows the layout of the fiber-optic cable (black line with numbers indicating distance in kilometers) deployed in the DAS-BúmmBúmm experiment in spring 2021. Locations of the research huts (GFUM) near one end of the cable and a GPS station at the other end are also shown, as are the years and approximate locations of previous fissure eruptions (orange and red). The site of Grímsvötn (red triangle) amid the Vatnajökull ice sheet in Iceland is indicated in the inset. Topographic information in this figure is based on ArcticDEM.

    2
    Grímsvötn volcano. Credit: The Smithsonian Institution (US)

    3
    Iceland’s Grimsvotn volcano erupts. Credit: NBC News.

    Icelandic legend tells of an outlaw named Grímur who hid in the highlands of the island after avenging the murder of his father. A widow assisted him, directing him to some remote lakes where he could sustain himself by fishing. However, there was already a giant living near the lakes. Grímur fought and killed the giant, so upsetting the giant’s daughter that she laid a curse on the landscape. From then on, fires would burn in the lakes and the surrounding woods would vanish.

    To this day Grímur’s lakes-Grímsvötn in Icelandic-continue to spit fire even as they are buried under hundreds of meters of the ice of Europe’s largest glacier Vatnajökull. In fact, since the settlement of Iceland, Grímsvötn has been the island’s most active volcano—and it may be due for another major eruption.

    In spring 2021, researchers from The Swiss Federal of Technology ETH Zürich [Eidgenössische Technische Hochschule Zürich)](CH) and The Icelandic Meteorological Office [Veðurstofa Íslands](IS) set out for Grímsvötn to take a closer look at its activity, using an emerging geophysical technology called distributed acoustic sensing (DAS; Figure 1 [above]). DAS can yield unprecedentedly high resolution data in hazardous and difficult-to-access environments. In addition to measuring previously unobserved seismic activity at the volcano, the experiment also indicated the presence of continuous seismic tremor and a variety of other signals at Grímsvötn not observed before in such detail.

    The Hazards of Grímur’s Lakes

    Grímsvötn is a complex volcanic system that is governed by both geothermal heat from below and the ice of the overlying glacier. The heat melts the underside of the glacier, creating runoff and forming a subglacial lake within the caldera of the volcano. This lake occasionally drains during major outburst floods called jökulhlaups, which inundate the coastal plains south of the ice cap. Past jökulhlaups from Grímsvötn have destroyed bridges and cut off transit between western and eastern Iceland.

    Recently, Grímsvötn again showed such increased activity. Around 20 November, GPS measurements recorded the ice shelf above Grímsvötn starting to subside slowly, marking the beginning of a jökulhlaup as water flowed out of the subglacial lake. The jökulhlaup peaked on 5 December in the Gígjukvísl glacier river, and more than 0.8 cubic kilometer of water in total drained from below the volcano.

    In addition to the flood hazard, ash clouds pose threats to humans and livestock when direct interaction between magma and meltwater causes Grímsvötn to erupt explosively. Recent eruptions occurred in 1998, 2004, and 2011, each of which sent plumes of ash and debris into the atmosphere (the 1998 and 2004 events were also associated jökulhlaups). These plumes can spread heavy layers of ash over the local landscape, cause intense lightning, and reduce air quality and visibility, conditions that can impair aircraft and roads. If winds are unfavorable during an eruption, ash clouds can also cause major shutdowns and economic damage in the air traffic industry as happened during the 2010 eruption of Eyjafjallajökull located about 140 kilometers southwest of Grímsvötn.

    Rapid and substantial pressure decreases-such as that seen beginning in late November-have previously caused Grímsvötn to erupt (in 2004, 1932, and 1922). The IMO, which is responsible for providing warnings about impending eruptions, was thus on full alert and raised the aviation alert level from yellow to orange as seismicity started to pick up at Grímsfjall, peaking with a magnitude 3.6 earthquake on 6 December. However, the seismicity quickly subsided that same day, and on 8 December, IMO lowered the code back to yellow.

    Instrumenting the Ice

    Conducting a large-scale field experiment in the middle of 7900-square-kilometer Vatnajökull was challenging. After months of planning, the effort began with our team of nine traveling by trucks from Reykjavík to the glacier’s edge. From there, we continued aboard snowmobiles, superjeeps (trucks specially equipped with large tires for traversing ice), and a snowcat, following a carefully selected route to Grímsvötn to avoid the largest crevasses. Over roughly 80 kilometers of ice, we hauled all the equipment we needed for our 5-day expedition, including three large cable drums, each roughly 50 kilograms and holding 4-kilometer-long segments of fiber-optic cable, until we reached three huts near the highest point of the caldera rim at Grímsfjall. Built in 1957, 1987, and 1994 to conduct scientific research, the huts—geothermally heated by the volcano and collectively housing a small kitchen, bunks, and even a steam sauna—served as our base of operations.

    The fiber-optic cable was the core component of our experiment. DAS makes use of a standard fiber-optic cable together with an instrument called an interrogation unit (IU), which sends laser pulses through the fiber and receives them back. Inhomogeneities in the fiber cause backscattering of the light, which is measured by the IU. Small shifts in the return timing of the backscattered signals can be related to localized deformations of the fiber caused by seismicity or other sources of vibration.

    Thus, long lengths of fiber can be used to create a dense seismic network, collecting measurements in the millihertz to kilohertz range every few meters with lower labor and financial costs compared with those from conventional seismic arrays covering areas of similar sizes. The high spatiotemporal sampling is especially beneficial in remote and harsh environments, such as Grímsvötn, where the installation of conventional arrays either would require substantially more personnel and time or is altogether infeasible. (In populated areas exposed to volcanic hazards, unused “dark” fibers in existing fiber-optic communications networks coupled with edge computing—data analysis that happens in real time at an instrument—may have great potential for noninvasive volcano monitoring and other applications of DAS.)

    To build our detection network at Grímsvötn, we set up the IU in one of the huts, where electricity and Internet are available, and from there, we laid out our 12 kilometers of fiber-optic cable in a hook-shaped pattern along much of the caldera rim and atop the subglacial lake (Figure 1). Using the snowcat equipped with a custom-made plow, we trenched the cable 50 centimeters deep into the snow thereby protecting it from atmospheric influences. Because the cable was delivered on three separate drums, the different segments had to be spliced together, which was a surgical task given that each fiber is about as thin as a human hair. This surgery was complicated by the fact that it had to be performed during the trenching, and thus in the back of a cold, cramped superjeep rather than in the relative comfort of the huts.

    Badminton and a Bad Connection

    Deploying the entire length of cable took 2 days, a process that ran smoothly overall despite the difficult conditions of working atop an active, glacier-capped volcano. During the deployment, we were always in direct contact with the volcano monitoring room at the IMO. At the first signs of volcanic unrest, we would have evacuated immediately.

    On the third day, we conducted hammer tests to locate the DAS channels and to provide first glimpses of seismic wave propagation in the ice. This entailed pounding a sledgehammer on the ice in different places so the fiber-optic cable would record the signals at those locations. In the data, we could then see exactly where along the cable the signals were recorded, allowing us to link the data with their geographic location. From these initial tests, the experimental setup—our “buried hair,” as we jokingly called it—appeared to work as expected. This success gave us reason to celebrate, and the team was excited to have a good time amid the challenging days of fieldwork.

    Among our supplies, we had packed a badminton set—not at all standard equipment because the glacier is notoriously windy—hoping for an opportunity to spice up the expedition in the event of low-wind conditions inside the caldera, which is partly shielded by Grímsfjall mountain. We were extremely lucky to experience such a day. We set up a net amid the snow and enjoyed a sunny break for badminton—albeit wearing snowsuits instead of shorts and T-shirts—surrounded by the hills of the caldera rim. With the help of a large speaker we had brought up the glacier, the celebration turned into a small party, and because both the speaker and the party were referred to as “búmmbúmm” in Icelandic, our experiment was subsequently named DAS-BúmmBúmm.

    After our celebrations, however, we learned the experiment would not be without hiccups. Our original plan included collecting 2 months of continuous measurements, but upon arrival back in Reykjavík, we found that the connection to our instruments was lost. A week later, after waiting for a storm to pass, we returned to Grímsvötn and diagnosed that this lack of communication occurred because of a broken drive in the instrument. The issue prevented it from recording, and we could not repair it atop the glacier—unfortunately, the DAS system was more “brokebroke” than “búmmbúmm.” Once we arranged for a replacement instrument, we went to Grímsvötn a third time and corrected the problem, and in the end we still managed to collect 1 month of measurements.

    Experimental Expectations

    Experiments on volcanoes are a relatively new application of DAS, with only a few examples to date, such as an experiment on Mount Meager in 2019, so the science is still exploratory. Our goal is to develop DAS as a real-time volcano monitoring tool. To achieve this, we need to conduct several DAS experiments in different volcanic settings to develop algorithms that can identify, locate, and characterize volcanic signals on the fly.

    We are still analyzing the data from this first-ever DAS deployment at Grímsvötn. So far, they reveal an unexpected level of seismic activity. Prior to the DAS-BúmmBúmm experiment, there had been one seismic station at Grímsvötn to record seismic signals, whereas we effectively recorded ground motions every 8 meters along the fiber-optic cable. With a single station only, it is hard to distinguish smaller signals from background noise, but in our DAS data, we can see the propagation of even the smallest signals. We recorded previously unknown tremor inside the caldera, for example, as well as frequently occurring small, local events that were detected all along the fiber-optic cable. These events may have been caused by a wide range of phenomena, such as volcanic and geothermal activity, icequakes, snow avalanches, and resonance of the subglacial lake and the overlying ice sheet (Figure 2). Because the cable loops closely past fumarole fields, their activity is likely recorded as well.

    4
    Fig. 2. This sample data plot shows ground deformation along the fiber-optic cable deployed at Grímsvötn over about 50 seconds. A large event arrived near the middle of the cable at about 18:44:50 on this day as it propagated through the glacier. The signal observed around kilometers 10–12 of the fiber, which sat on top of the subglacial lake, oscillated with longer periods than the large event and may have been caused by bending of the ice sheet on top of the lake.

    In our initial analyses, we are locating the detected events, carefully accounting for the rough topography and the presence of the ice and the lake, which affect seismic signals differently from the bedrock below. This work will be followed by a process of iteratively inverting the data to help determine the internal structure of Grímsvötn, including its magma chamber and conduits. We hope that our results and experiences from this experiment—and from future experiments planned for a range of volcanological settings in Santorini, Tenerife, and Indonesia—will shed light on hidden processes at hazardous active volcanoes and bring us closer to enhanced volcano monitoring using versatile fiber-optic cables.

    See the full article here .

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  • richardmitnick 10:46 am on December 24, 2021 Permalink | Reply
    Tags: "A Bright LED-Lit Future for Ocean Sciences", An estimated 436 submarine fiber-optic cables totaling 1.3 million kilometers in length (enough for 32 trips around Earth’s equator) are currently in service., , Aquatic photochemistry as a discipline has grown immensely over the past half century., Autonomous underwater vehicles (AUVs) communicate and work together., , Eos, LEDs can also help ensure that high-quality data are collected., LEDs have taken over the global lighting market. Now it’s time for this versatile low-cost and energy-efficient technology to illuminate oceanic processes., , The future of studying the ocean lies in the development of low-cost vehicles; sensors and instruments., The oceanographic research community is currently developing fleets of autonomous underwater vehicles (AUVs)., These fleets will be able to take measurements across more expansive spatial and temporal scales than are currently possible., Wireless underwater LED technology is in fact already largely proven and in use.   

    From Eos: “A Bright LED-Lit Future for Ocean Sciences” 

    From AGU
    Eos news bloc

    From Eos

    20 December 2021
    Collin P. Ward

    LEDs have taken over the global lighting market. Now it’s time for this versatile low-cost and energy-efficient technology to illuminate oceanic processes.

    1
    A remote underwater environmental monitoring unit, or REMUS (yellow), tests through-­water communications using a wireless, blue light­emitting diode (LED)­based optical modem at Iselin Dock in Woods Hole, Mass. Credit: S.P. Whelan © The Woods Hole Oceanographic Institution.

    Cutting the cord at home—replacing traditional cable television service with alternatives like streaming video—is an increasingly common trend these days. In oceanography, scientists are seeing their own version of this trend, one that might more accurately be called “cutting the tether.” Both trends have been matched—and aided—by the rapid growth of light-emitting diode (LED) technology and applications.

    Recently, there has been a push in the oceanographic community to replace hard-wired, fiber-optic communication tethers connected to instruments with wireless, through-water communications. Think Wi-Fi for the ocean. For example, in 2019, untethered, wireless communications allowed then Seychelles president Danny Faure to address his constituents and raise awareness about ocean health from a submersible vehicle 124 meters below the sea surface, an event that was livestreamed to thousands around the world. The core technology that made this livestream possible comprised high-powered, blue LEDs that package and rapidly transmit data through the water [Farr et al., 2010*].

    LEDs Have Transformed How We Light Our Homes…

    The foundational technology of LEDs has been around for more than a century, but only in the past decade or so have LEDs become transformative to society.

    In 2010, LEDs accounted for 1% of the global lighting market; by 2020, this share had risen to 55%. This rapid growth has profoundly reshaped the industry, even contributing to the decision by General Electric, long known as the leading innovator in lighting, to sell its lighting division in 2020. At some point this decade, the entire global lighting market is expected to shift to LEDs, with the LED lighting market rising from roughly $60 billion in 2021 to an estimated $135 billion in 2028.

    The transition from incandescent bulbs to LEDs has been driven by both policy changes and consumer demand. In the United States, for example, the Energy Independence and Security Act passed in 2007 mandated that many household lightbulbs become 25% more efficient than incandescent bulbs. Similar polices have been adopted by the European Union and China.

    These policy changes left consumers with two options: compact fluorescent lamps (CFLs) or LEDs. LEDs are more than 40% more energy efficient and last 3–7 times longer than CFLs, and as LED bulb prices have dropped, consumers have increasingly opted for them.

    2
    Shown here are the relative magnitudes of impacts of different lighting sources over their life cycles on natural resources, air, soil, and water. The impacts of compact fluorescent (red) and LED (green and purple) bulbs are substantially less than those of incandescent bulbs (blue). Credit:The Department of Energy (US).

    Although the choice for consumers has been relatively easy to make, many people do not fully appreciate the positive environmental impacts of adopting LED technology. In 2017, information provider IHS Markit estimated that the adoption of LED lighting reduced global carbon dioxide emissions that year by more than half a billion tons, or 1.5%. Life cycle assessments also indicate that compared with using incandescent or CFL bulbs, LED technology reduces hazardous waste production and risks to ecosystem and human health and better preserves air, soil, and water quality.

    …And Now They Are Transforming How We Study the Ocean

    The future of studying the ocean lies in the development of low-cost vehicles; sensors and instruments. These tools will enable continuous monitoring of ocean processes and allow a broader contingent of the global population to participate in ocean research and sustainability efforts. LEDs, which are useful not only for underwater lighting but also for transmitting data through water, are primed to play an important role in this future vision.

    3
    Autonomous underwater vehicles (AUVs) communicate and work together to survey a hydrothermal vent at the bottom of the ocean in this illustration. LED lights aboard the AUVs transmit data collected through the water to receivers secured to cabled moorings. Fiber­optic cables then deliver the data from the moorings to scientists on shore, allowing them to inspect the data and, if needed, adjust their research plan in near­real time. Credit: © E.P. Oberlander/Woods Hole Oceanographic Institution.

    The oceanographic research community is currently developing fleets of autonomous underwater vehicles (AUVs) to collect physical, acoustic, chemical, and biological data that help us understand how the ocean works and how it will respond to human-induced pressures from climate change and pollution. For example, these fleets collect data that characterize (1) the changing strengths of ocean currents like the Gulf Stream; (2) the distribution and sustainability of commercially important fisheries; (3) the locations and movements of endangered marine mammals in proximity to shipping vessels and fishing gear; (4) changes in water quality parameters like pH, temperature, nutrient loads, and oxygen levels; and (5) greenhouse gas storage. These fleets also monitor the integrity of and ecosystem impacts from ocean infrastructure like installations for offshore oil exploration, wind energy production, and aquaculture.

    In theory, these fleets will be able to take measurements across more expansive spatial and temporal scales than are currently possible while also minimizing the use of expensive and energy-intensive crewed research vessels. But for these AUV fleets to be more than just groups of individual vehicles operating in proximity, they need to communicate and coordinate their activities. This is where advanced LED technology comes in.

    An estimated 436 submarine fiber-optic cables totaling 1.3 million kilometers in length (enough for 32 trips around Earth’s equator) are currently in service, making up a complex global web of rapid-transmission communications conduits. It is this web that allows us to call friends and family nearly anywhere around the world with the touch of a button. Data are communicated through these specialty glass-lined cables in the form of high-powered light, often emitted by LEDs, that bounces from side to side in a process known as total internal reflection. Without these fiber-optic cables (i.e., if the cord, or tether, were cut), light-borne data could not travel nearly as far because the light emissions attenuate quickly.

    The choice of light color makes a difference, however. In the ocean, the main attenuators of light are chromophoric dissolved organic matter (CDOM) and water itself (Figure 1). CDOM readily absorbs ultraviolet (UV) light, whereas water readily absorbs green and red light. Because blue light largely escapes absorption by CDOM and water, it travels hundreds of meters into the ocean, much deeper than UV, green, and red light. This is why the ocean is blue and why wireless underwater optical communication systems use high-powered blue LEDs to transmit data.

    3
    Fig. 1. The relative importance of chromophoric dissolved organic matter (CDOM) and water to total light at-tenuation in the ocean is depicted here. (top) CDOM is the main attenuator of UVB, UVA, and violet light, whereas water is the main attenuator of green, yellow, orange, and red light. (bottom) Blue light penetrates deepest into the ocean because it escapes absorption by CDOM and water.

    Wireless underwater LED technology is in fact already largely proven and in use. For example, at a seafloor borehole observatory, LED-based optical modems rapidly transmit data from in situ sensors to AUVs or remotely operated vehicles more than 100 meters away—just as similar modems did during President Faure’s livestream from Seychelles. Moreover, as seabed pipelines that deliver oil and gas from thousands of active offshore rigs to refineries on land are built and maintained, LED-based optical modems help rapidly transfer data to engineers. These data allow the engineers to monitor and react in near-real time to conditions at the seafloor, improving the accuracy and speed with which the pipelines can be laid and optimizing monitoring of pipeline health to avoid, or at least minimize, damages and environmental harm from undersea pipeline ruptures.

    LEDs can also help ensure that high-quality data are collected. All sensors in the ocean—whether optical, chemical, electrical, or acoustic—are prone to biofouling or other interferences from living organisms like algal slime and barnacles that grow on sensor surfaces. Traditional approaches to minimizing biofouling involve mechanical means like wipers and shutters or chemical means like biocides. These approaches, however, leave a lot to be desired, particularly in the application of biocides that can cause collateral harm to more than just the intended organisms.

    4
    Conductivity data collected using a conductivity probe deployed at sea for several months and treated with UVC light (left) matched very closely with true values, whereas data collected from a biofouled probe not treated with UVC (right) drifted away from the true values within a week [Bueley et al., 2014]. Credit: Ocean Networks Canada (CA) and AML Oceanographic.

    In turn, oceanographic researchers have recently been pushing for chemical-free antifouling alternatives. Given their simplicity, low costs, and power requirements, UV LEDs, particularly those that emit UVC, appear to be the wave of the future [Delgado et al., 2021], and preliminary results on their effectiveness are promising. UVC treatment has been shown to minimize biofouling of ocean sensors, improving the quality of pH, conductivity, and turbidity data collected [Bueley et al., 2014; Armstrong and Snazelle, 2017], and to allow longer deployments at sea.

    Adding to the Photochemical Toolbox

    From UV LEDs used for disinfection to visible light LEDs used for communications, the wavelengths generated by LEDs span the entire range of natural sunlight that reaches the sea surface. This fact opens the door for scientists to use LEDs to study how sunlight alters the cycling of major and minor elements and the fate of pollutants in the ocean, processes that influence marine ecosystems and the overall Earth system in countless ways.

    4
    The LED-­based reactor assembly illustrated here was designed to determine the wavelength (λ) dependence of light-­driven reactions in surface waters that affect, for example, cycling of major and minor elements and the fate of pollutants. Wavebands range from UVB (278 nanometers) to red light (629 nanometers). A discussion of the pros and cons of this assembly compared with other technologies (related to, e.g., costs, sample throughput, portability, and data quality), as well as a step-­by­-step plan to build and validate an assembly, is given by Ward et al. [2021]. Credit: Reprinted with permission from Ward et al. [2021], ©2021 The American Chemical Society (US).

    Aquatic photochemistry as a discipline has grown immensely over the past half century, yet in that time our understanding of how the rates of light-driven reactions depend on sunlight wavelength has not changed much. This knowledge gap matters because reaction rates of photochemical processes vary considerably from day to day, even hour to hour, and at different depths in the ocean for several reasons. First, the energy of light photons decreases with increasing light wavelength; for example, UV light is more energetic than blue light, which in turn is more energetic than red light. This variation is why sunscreen contains mineral additives that specifically block powerful, and biologically hazardous, UV light. It’s also why red pigments in street signs and artistic masterpieces fade quicker than blue pigments: More powerful blue light is absorbed by and destroys red pigments, causing visible fading, whereas absorption of less powerful red light allows blue pigments to last longer. Second, although visible light is weaker than UV light, about 10 times more visible light reaches Earth’s surface than UV light [Apell and McNeill, 2019]. Third, different light wavelengths penetrate into the ocean to different extents, with blue light penetrating the deepest.

    Our limited understanding of the wavelength dependence of aquatic photochemical reactions is driven largely by cost and technological limitations. Determining wavelength dependence requires specialized equipment like high-powered lasers, solar simulators, and monochromators, which help isolate different wavelengths of the solar spectrum. This equipment is costly and energy intensive and lacks portability, often requiring researchers to stabilize or preserve their field samples for experimentation back in laboratories on land. Moreover, these approaches have low sample throughput—only one or two samples can be analyzed per day, which considerably raises labor costs.

    LEDs present an exciting opportunity to overcome many of these limitations without sacrificing data quality [Ward et al., 2021], allowing a wider contingent of researchers to study rates of sunlight-driven processes over spatial and temporal scales that were previously inaccessible. Widespread adoption and application of this technology could thus allow the incorporation of photochemical processes into Earth system models and afford more accurate depictions of how major and minor elements and pollutants cycle in the upper ocean.

    More People in More Places

    The disruptive potential of LED technology is so broad that it is poised to play key roles in making progress toward several of the United Nations (U.N.) Sustainable Development Goals. These goals include eliminating poverty; ensuring good health and well-being for everyone; ensuring clean water supplies and adequate sanitation; fostering resilient and inclusive industry, innovation, and infrastructure; and conserving and sustainably using the oceans, seas, and marine resources.

    For example, just as UVC LEDs are currently used to disinfect indoor air to combat the spread of the COVID-19-causing SARS-CoV-2 virus and other pathogens, UVC LEDs offer a low-cost and effective means to disinfect and destroy viruses and micropollutants in drinking water [Chen et al., 2017]. Moreover, visible light LEDs are a foundational technology in vertical farming, a relatively new industry that grows crops in stacked layers under controlled conditions. A key aim of vertical farming is to alleviate negative ecosystem impacts of traditional farming operations, such as reduced carbon sequestration in soils, depleted and impaired freshwater resources, and damages caused by pesticide and herbicide applications [Benke and Tomkins, 2017].

    In particular, the effect of LEDs on the goal of sustainably using the oceans is becoming increasingly clear. Ocean science is global by nature, but in practice, participation is limited largely to institutions, scientists, and students in wealthy nations while being cost prohibitive in lower-income nations and for many people in ocean-dependent communities. In response to the U.N.’s call for a Decade of Ocean Science for Sustainable Development, which began in 2021, many scientists have argued for improving sustainability and equity in the ocean sciences community [Pendleton et al., 2020; Singh et al., 2021; Valauri-Orton et al., 2021; Wang, 2021]. One common recommendation in these arguments is to invest in the development of low-cost sensors and technologies to lower barriers and encourage broader participation.

    Just as low-cost LED-based sensors empower air quality monitoring in developing nations that disproportionately experience the health burden of poor air quality, it is likely that LEDs will contribute substantially to the development of low-cost sensors to monitor ocean health. Such an evolution could advance equity in the ocean sciences, allowing more people in more places to participate. It could also advance sustainability by allowing us to observe and monitor more of the ocean more often, offering a wealth of information about marine conditions and health with which to make informed decisions about how we treat it.

    Acknowledgments

    I offer many thanks to Aleck Wang and Anna Michel for helpful discussions while I was researching this topic and to Ken Kostel, Matthew Long, Danielle Freeman, Mike Mazzotta, Taylor Nelson, Maurice Tivey, and Anna Walsh for providing constructive feedback on the article. Thanks to Katie Linehan for tolerating years of incessant conversations about how cool LEDs are. Funding was provided by the Department of Fisheries and Oceans Canada Multi-Partner Research Initiative, the National Science Foundation, and Woods Hole Oceanographic Institution.

    *All citations below with links.

    References:

    Apell, J. N., and K. McNeill (2019), Updated and validated solar irradiance reference spectra for estimating environmental photodegradation rates, Environ. Sci. Processes Impacts, 21(3), 427–437, https://doi.org/10.1039/C8EM00478A.

    Armstrong, B., and T. Snazelle (2017), Field testing of an AML oceanographic cabled ultraviolet anti-biofouling system in an estuarine setting, in OCEANS 2017-Anchorage, pp. 1–6, Inst. of Electr. and Electron. Eng., Piscataway, N.J., ieeexplore.ieee.org/document/8232067.

    Benke, K., and B. Tomkins (2017), Future food-production systems: Vertical farming and controlled-environment agriculture, Sustainability Sci. Pract. Policy, 13(1), 13–26, https://doi.org/10.1080/15487733.2017.1394054.

    Bueley, C., D. Olender, and B. Bocking (2014), In-situ trial of UV-C as an antifoulant to reduce biofouling induced measurement error, J. Ocean Technol., 9(4), 49–67, thejot.net/article-preview/?show_article_preview=601.

    Chen, J., S. Loeb, and J. H. Kim (2017), LED revolution: Fundamentals and prospects for UV disinfection applications, Environ. Sci. Water Res. Technol., 3(2), 188–202, https://doi.org/10.1039/C6EW00241B.

    Delgado, A., C. Briciu-Burghina, and F. Regan (2021), Antifouling strategies for sensors used in water monitoring: Review and future perspectives, Sensors, 21(2), 389, https://doi.org/10.3390/s21020389.

    Farr, N., et al. (2010), An integrated, underwater optical/acoustic communications system, in OCEANS’10 IEEE-Sydney, pp. 1–6, Inst. of Electr. and Electron. Eng., Piscataway, N.J., https://doi.org/10.1109/OCEANSSYD.2010.5603510.

    Pendleton, L., K. Evans, and M. Visbeck (2020), Opinion: We need a global movement to transform ocean science for a better world, Proc. Natl. Acad. Sci. U. S. A., 117, 9,652–9,655, https://doi.org/10.1073/pnas.2005485117.

    Singh, G. S., et al. (2021), Opinion: Will understanding the ocean lead to “the ocean we want”?, Proc. Natl. Acad. Sci. U. S. A., 118, e2100205118, https://doi.org/10.1073/pnas.2100205118.

    Valauri-Orton, A., et al. (2021), EquiSea: The ocean science fund for all, Mar. Technol. Soc. J., 55(3), 106–107, https://doi.org/10.4031/MTSJ.55.3.41.

    Wang, Z. A. (2021), Accelerating global ocean observing: Monitoring the coastal ocean through broadly accessible, low-cost sensor networks, Mar. Technol. Soc. J., 55(3), 82–83, https://doi.org/10.4031/MTSJ.55.3.52.

    Ward, C., et al. (2021), Rapid and reproducible characterization of the wavelength dependence of aquatic photochemical reactions using light-emitting diodes, Environ. Sci. Technol. Lett., 8, 437–442, https://doi.org/10.1021/acs.estlett.1c00172.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
  • richardmitnick 10:59 am on December 21, 2021 Permalink | Reply
    Tags: "How Fault Surface Features Can Tell Us About Future Earthquakes", A quick assessment of a fault’s maturity will help scientists better understand the risks they pose to nearby communities., , , , Eos, Fault line characteristics such as structural maturity can give hints about how a future earthquake may act., , Mature and immature faults generate very different earthquakes. Mature faults release less stress-their rupture propagates quickly down their length. Immature faults create high-energy slower quakes.,   

    From Eos: “How Fault Surface Features Can Tell Us About Future Earthquakes” 

    From AGU
    Eos news bloc

    From Eos

    21 December 2021
    Elizabeth Thompson

    1
    The San Andreas Fault, a mature strike-slip fault, is well studied because it lies near major population centers. Understanding fault maturity here and at other faults can help scientists model earthquakes and assess risks to nearby communities. Credit: Doc Searls, CC BY-SA 2.0.

    Earthquakes cannot be forecast like weather, but fault line characteristics, such as structural maturity, can give hints about how a future earthquake may act. Structural maturity is related to the age of the fault, but especially important is its “experience,” how much a fault has developed and changed over time and activity.

    Mature and immature faults generate very different earthquakes. Mature faults release less stress, but their rupture propagates quickly down their length, whereas immature faults create high-energy, slower quakes. A quick assessment of a fault’s maturity will help scientists better understand the risks they pose to nearby communities.

    A new study seeks to quantify faults’ maturity into a useful metric to help assess earthquake risks. Manighetti et al. measured surface features of fault lines that previous studies had evaluated at several maturity levels. They then analyzed their measurements to see how they related to the maturity judgment.

    The researchers found that corrugation (i.e., undulation) and step-overs were good maturity indicators. Immature faults were reliably shorter, with high corrugation and high step-over density. As faults matured, they lengthened and smoothed out, reducing undulations and step-over density.

    These traits are not only reliable across faults; they are also detectable at low resolutions. Scientists can map as little as a third of a fault’s length at relatively low resolution and still generate an accurate assessment of a fault’s maturity. This means that these metrics are practical for models and hazard assessments. Applying neural networks to the mapping process would make this method even easier, according to the authors.

    Science paper:
    Geophysical Research Letters

    _____________________________________________________________________________________

    Earthquake Alert

    1

    Earthquake Alert

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

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

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015
    Meet The Quake-Catcher Network
    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.
    After almost eight years at Stanford University (US), and a year at California Institute of Technology (US), the QCN project is moving to the University of Southern California (US) Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

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

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

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

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

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

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

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.
    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

    Below, the QCN Quake Catcher Network map
    QCN Quake Catcher Network map

    QuakeAlertUSA

    1

    About Early Warning Labs, LLC

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

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

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

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

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

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

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

    Earthquake Early Warning Introduction

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

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

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

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

    Earthquake Early Warning Background

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

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

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

    GNSS-Global Navigational Satellite System

    1
    GNSS station | Pacific Northwest Geodetic Array, Central Washington University (US)
    _____________________________________________________________________________________

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

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

     
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