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  • richardmitnick 3:56 pm on September 9, 2019 Permalink | Reply
    Tags: , , , Vulcanology   

    From The New York Times: “We’re Barely Listening to the U.S.’s Most Dangerous Volcanoes” 

    New York Times

    From The New York Times

    Sept. 9, 2019
    Shannon Hall

    A thicket of red tape and regulations have made it difficult for volcanologists to build monitoring stations along Mount Hood and other active volcanoes.

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    Mount Hood in Oregon is one of 161 active volcanoes in the United States, many of them in the Pacific Northwest’s Cascade Range.Credit Amanda Lucier for The New York Times

    Seth Moran is worried about Mount Hood.

    In the 1780s, the volcano rumbled to life with such force that it sent high-speed avalanches of hot rock, gas and ash down its slopes. Those flows quickly melted the snow and ice and mixed with the meltwater to create violent slurries as thick as concrete that traveled huge distances. They destroyed everything in their path.

    Today, the volcano, a prominent backdrop against Portland, Ore., is eerily silent. But it won’t stay that way.

    Mount Hood remains an active volcano — meaning that it will erupt again. And when it does, it could unleash mudflows not unlike those from Colombia’s Nevado del Ruiz volcano in 1985. There, a mudflow entombed the town of Armero, killing roughly 21,000 people in the dead of night.

    On Mount Hood, “any little thing that happens could have a big consequence,” said Dr. Moran, scientist-in-charge at the federal Cascades Volcano Observatory.

    And yet the volcano is hardly monitored. If scientists miss early warning signs of an eruption, they might not know the volcano is about to blow until it’s too late.

    Determined to avoid such a tragedy, Dr. Moran and his colleagues proposed installing new instruments on the flanks of Mount Hood in 2014. Those include three seismometers to measure earthquakes, three GPS instruments to chart ground deformation and one instrument to monitor gas emissions at four different locations on the mountain.

    But they quickly hit a major hiccup: The monitoring sites are in wilderness areas, meaning that the use of the land is tightly restricted. It took five years before the Forest Service granted the team approval in August.

    The approval is a promising step forward, but Dr. Moran and his colleagues still face limitations, including potential legal action that may block their work.

    Such obstacles are a problem across the United States where most volcanoes lack adequate monitoring. Although federal legislation passed in March could help improve the monitoring of volcanoes like Mount Hood, scientists remain concerned that red tape could continue to leave them blind to future eruptions, with deadly consequences.

    Listening for rumbles and belches

    The United States is home to 161 active volcanoes, many of which form a line along the west coast through California, Oregon, Washington and Alaska. Seven of the 10 most dangerous American volcanoes are within the Cascade Range, and six of those are not adequately monitored.

    In contrast, countries like Japan, Iceland and Chile smother their high-threat volcanoes in scientific instruments.

    “The U.S. really doesn’t have anything to this level,” said Erik Klemetti, a volcanologist at Denison University in Ohio.

    Yet there is no question that better monitoring could save lives. Volcanoes don’t typically erupt without warning. As Mount St. Helens awoke in May 1980, a series of small earthquakes could be felt on the surface nearby. Shortly thereafter, the volcano started to deform. Steam explosions sculpted a new crater, while a bulge emerged on the volcano’s north flank. Earthquakes continued, landslides rumbled and ash-rich plumes erupted — all before the main event.

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    Mount St. Helens awoke in May 1980. OregonLive.com

    Although not all volcanoes follow such a steady, pre-eruptive pattern, they typically either tremble, deform or belch volcanic gases — meaning that if scientists monitor these three signals, they will likely be able to forecast when a volcanic eruption will happen.

    Take Hawaii as an example. Shortly after earthquakes picked up at the Kilauea volcano on April 30, 2018, scientists at the Hawaiian Volcano Observatory could tell that they were not only increasing, but they were also propagating to the east.

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    Kilauea volcano on April 30, 2018. Lava flowing on May 6 through the Leilani Estates subdivision. Credit Bruce Omori/EPA, via Shutterstock.

    “That was not only cool, it was vital for emergency management,” Dr. Moran said.

    Scientists used those signals to project where magma might erupt, and planners evacuated residents in that area. The eruption destroyed more than 700 homes, but remarkably no one died.

    And it was all thanks to 60 seismic stations located across the island.

    “Without those instruments, we would have been blind,” said Tina Neal, the scientist-in-charge at the Hawaiian Volcano Observatory. “While we would have known something was happening, we would have been less able to give guidance about where and what was likely to happen.”

    Nature’s Bill of Rights

    Dr. Moran and his colleagues had that example in mind as they pressed their case for adding instruments to Mount Hood.

    They submitted a proposal to the Forest Service in 2014. But the instruments — which will be housed in four-feet-tall boxes with radio antennas and solar panels on the outside — violate the Wilderness Act, which prohibits any new structures and even noise pollution within federal wilderness areas.

    “I see the Wilderness Act as nature’s bill of rights,” said George Nickas, the executive director of Wilderness Watch, a conservation group that opposed volcano monitoring in federal wilderness. “I think it is so important to have places like that where we can just step back, out of respect and humility, and appreciate nature for what it is.”

    In reviewing Dr. Moran’s proposal, the Forest Service provided the public with an opportunity to comment, during which they received more than 2,000 statements — most of which agreed that the wilderness needs safeguarding.

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    U.S.G.S. volcano monitoring equipment, right, on Mount St. Helens. Credit Amanda Lucier for The New York Times.

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    Fiberglass enclosures for volcano monitoring equipment awaiting placement on Mount Hood. Credit Amanda Lucier for The New York Times.

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    When Mount St. Helens first began to rumble, scientists couldn’t tell if the quakes originated under the volcano itself or at a nearby fault. Scientists rushed to place additional instruments and within days they knew the volcano itself was shaking. Credit Amanda Lucier for The New York Times.

    To Jonathan Fink, a geologist at Portland State University who also wrote a public comment in favor of volcano monitoring, this argument is misplaced.

    “I’m all for protecting wilderness,” Dr. Fink said. “But this is just a question of public safety. And I think letting a helicopter in to put some instruments in that can then be monitored remotely seems like a pretty minor exception to the wilderness policies.”

    Even so, many critics argue that we can’t make even a single exception — or there won’t be wilderness at all.

    “It’s not wilderness if you have structures, if you have roads, if you have motorization,” said Gary Macfarlane, Wilderness Watch’s president. “In fact, it’s antithetical to the whole idea of wilderness.”

    Lessons from Mount St. Helens

    Other critics say the project is far from necessary. “If we can do something like land one of those landers on Mars, we can move a few miles back from a volcanic feature and monitor it from a little further away,” said Bernie Smith, a retired employee of the Forest Service who wrote a public comment against the project.

    But Dr. Moran and others argue that the work is not possible unless they get up close, and before the volcano begins to rock.

    “The name of the game is to be able to detect and correctly interpret these warning signs as soon as possible — to give society as much time as possible to get ready,” Dr. Moran said.

    When Mount St. Helens first began to rumble, scientists couldn’t tell if the quakes originated under the volcano itself or five miles away at a nearby fault. They only had one seismometer two miles to the west of the volcano. So they rushed to place more instruments on its slopes (a risk that would not be allowed today) and within days they knew the volcano itself was shaking.

    “Looking back on it, it’s really miraculous that they were able to do what they did,” Dr. Moran said.

    .7
    The Calbuco volcano erupting in southern Chile on April 22, 2015. Credit Diego Main/Agence France-Presse — Getty Images

    Scientists have since learned that we don’t always get as much time as Mount St. Helens allowed. At Calbuco, a volcano in southern Chile that’s similar to the volcanoes in the Cascades, all was quiet during the early afternoon of April 22, 2015. But tremors began in the late afternoon, and by 6:04 p.m. local time, the mountain was sending a plume of gas 10 miles into the sky.

    With such a narrow window, the first line of defense is to have a solid monitoring network in place whenever a volcano awakens.

    “You’re going to either get in there ahead of time and put in the instrumentation you need, or you’re just going to accept that you’re going to go blind into the entire eruptive period and whatever happens, happens,” said Jacob Lowenstern, a geologist with the United States Geological Survey.

    Not if, but when

    Although none of these volcanoes appear to be building toward an eruption today, there is no question that they pose a serious hazard.

    “The U.S.G.S. has a deep understanding that these volcanoes are going to erupt again — within our lifetimes, our children’s lifetimes,” said Carolyn Driedger, a hydrologist at the Cascades observatory. “The evidence is all there.”

    Beyond Mount Hood, Mount Rainier near Seattle could also unleash viscous volcanic mudflows. There, 80,000 people live in the path of disaster and yet the mountain only has 19 instruments, which scientists say is not enough given its vast size.

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    Aerial photo of Mount Rainier from the west. Stan Shebs

    And even volcanoes that don’t loom so close to populated areas could have far-reaching effects.

    Glacier Peak in northern Washington has produced some of the most explosive eruptions in the contiguous United States, meaning the ability to throw enough ash into the air to halt air traffic for days or even weeks and cost billions of dollars. It has only one seismometer.

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    Glacier Peak. Walter Siegmund

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    Andy Lockhart, a geophysicist at the Cascades observatory, working on a tripwire for part of a system to detect debris flow to be placed on Mount Rainier. Credit Amanda Lucier for The New York Times.

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    Seismometers at the Cascades Volcano Observatory awaiting placement on Mount Hood. Credit Amanda Lucier for The New York Times.

    Without equipment to detect the eruption, airplane passengers just might find themselves living a high-altitude nightmare. In 1989, a Boeing 747 flew through an undetected ash cloud in Alaska. All four engines shut down and the airplane went into a nose-dive. It descended 13,000 feet before the pilots were able to restart the engines. Hundreds of thousands of people fly across the West Coast and above active volcanoes every day.

    Eruptions in Alaska and California would also be felt across the nation. Anchorage is a major cargo hub, meaning that many FedEx or U.P.S. packages travel through Alaska. But an eruption might bring that to an alarming halt. And because California produces a large portion of the nation’s food, an eruption might limit the fruits and vegetables found at supermarkets as far as the East Coast.

    “We’re not just doing this for academic purposes. This is so we can give good information to emergency managers,” Dr. Driedger said. “That’s the end in all of this.”

    Hoping for slumber

    Despite the permit’s recent approval, Dr. Driedger notes that there are still a number of steps before any instruments can be placed on Mount Hood. They will now have to choreograph the assembly of instruments, hire personnel and schedule helicopter trips around weather and other potential obstacles.

    Moreover, the Forest Service and the observatory could still face a legal challenge from Wilderness Watch or other groups that adds years to the installation, if not blocking it altogether.

    “This is more proof that the Forest Service has abandoned any pretense of administering wilderness as per the letter or spirit of the Wilderness Act,” said Mr. Macfarlane, whose group is discussing litigation with an attorney but has not yet decided whether to file suit.

    And then there is more work to be done monitoring other hazardous volcanoes beyond Mount Hood.

    Volcanologists across the nation were pleased this March when Congress passed the National Volcano Early Warning and Monitoring System Act, which seeks to ensure that volcanoes nationwide are adequately monitored.

    But the bill is only an authorization — meaning that Congress has not actually invested the $55 million over five years required to apply for new permits, install more equipment and pay to monitor 34 of the nation’s most dangerous volcanoes. Nor will it change the fact that scientists like Dr. Moran must still grapple with regulations protecting federal wilderness.

    So Dr. Moran, aware that litigation is a possibility, is moving forward with caution. This month, his team will begin to install monitoring stations at Mount Hood. He then hopes the Forest Service will issue a permit to install equipment at Glacier Peak, then turn back to Washington’s Mount Baker. Eventually he would like to install more instruments on Mount Hood, but first he needs to create sufficient networks elsewhere.

    While they wait, Dr. Moran and his colleagues will hold their breath, hopeful that these volcanoes stay in a deep slumber, but aware that one just might rouse at any moment.

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    Location is not identified. Amanda Lucier for The New York Times.

    See the full article here .

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  • richardmitnick 4:02 pm on September 5, 2019 Permalink | Reply
    Tags: "Research shows why there’s a ‘sweet spot’ depth for underground magma chambers", A new study reveals why the magma chambers that feed recurrent and often explosive volcanic eruptions tend to reside in a very narrow depth range within the Earth’s crust., , , Depths of six to 10 kilometers generally correspond to pressures of about 1.5 kilobars on the shallow side and 2.5 kilobars on deep side., The research makes use of computer models that capture the physics of how magma chambers reservoirs in the crust that contain partially molten rock evolve over time., Vulcanology   

    From Brown University: “Research shows why there’s a ‘sweet spot’ depth for underground magma chambers” 

    Brown University
    From Brown University

    Computer models show why eruptive magma chambers tend to reside between six and 10 kilometers underground.

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    A new study reveals why the magma chambers that feed recurrent and often explosive volcanic eruptions tend to reside in a very narrow depth range within the Earth’s crust. The findings, published in Nature Geoscience, could help scientists to better understand volcanic processes the world over.

    The research makes use of computer models that capture the physics of how magma chambers, reservoirs in the crust that contain partially molten rock, evolve over time. The models showed that two factors — the ability of water vapor to bubble out of the magma, and the ability of the crust to expand to accommodate chamber growth — are the key factors constraining the depth of magma chambers, which are generally found between six and 10 kilometers deep.

    “We know from observations that there seems to be a sweet spot in terms of depth for magma chambers that erupt repeatedly,” said Christian Huber, a geologist at Brown University and the study’s lead author. “Why that sweet spot exists has been an open question for a long time, and this is the first study that explains the processes that control it.”

    Depths of six to 10 kilometers generally correspond to pressures of about 1.5 kilobars on the shallow side and 2.5 kilobars on deep side. The models showed that at pressures less than 1.5 kilobars, water trapped within the magma forms bubbles readily, leading to violent volcanic explosions that blast more magma out of a chamber than can be replaced. These chambers quickly cease to exist. At pressures more than 2.5 kilobars, warm temperatures deep inside the Earth make the rocks surrounding the magma chamber soft and pliable, which enables the chamber to grow comfortably without erupting to the surface. These systems cool and solidify over time without ever erupting.

    “Between 1.5 and 2.5, the systems are happy,” Huber said. “They can erupt, recharge and keep going.”

    The key to the models, Huber said, is that they capture the dynamics of both the host crust and of the magma in the chamber itself. The ability of deep magma chamber to grow without erupting was fairly well understood, but the limit that water vapor exerts on shallow magma chambers hadn’t been appreciated.

    “There hadn’t been a good explanation for why this habitable zone should end at 1.5 kilobars,” Huber said. “We show that the behavior of the gas is really important. It simply causes more mass to erupt out than can be recharged.”

    Huber says the findings will be helpful in understanding the global magma budget.

    “The ratio of magma that stays in the crust versus how much is erupted to the surface is a huge question,” Huber said. “Magma supplies CO2 and other gases to the atmosphere, which influences the climate. So having a guide to understand what comes out and what stays in is important.”

    Coauthors on the paper Meredith Townsend, WimDegruyter and Olivier Bachmann. The work was supported by the National Science Foundation (NSF-EAR 1760004) and the Swiss National Fund (200021_178928).

    See the full article here .

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    Welcome to Brown

    Brown U Robinson Hall
    Located in historic Providence, Rhode Island and founded in 1764, Brown University is the seventh-oldest college in the United States. Brown is an independent, coeducational Ivy League institution comprising undergraduate and graduate programs, plus the Alpert Medical School, School of Public Health, School of Engineering, and the School of Professional Studies.

    With its talented and motivated student body and accomplished faculty, Brown is a leading research university that maintains a particular commitment to exceptional undergraduate instruction.

    Brown’s vibrant, diverse community consists of 6,000 undergraduates, 2,000 graduate students, 400 medical school students, more than 5,000 summer, visiting and online students, and nearly 700 faculty members. Brown students come from all 50 states and more than 100 countries.

    Undergraduates pursue bachelor’s degrees in more than 70 concentrations, ranging from Egyptology to cognitive neuroscience. Anything’s possible at Brown—the university’s commitment to undergraduate freedom means students must take responsibility as architects of their courses of study.

     
  • richardmitnick 12:53 pm on August 31, 2019 Permalink | Reply
    Tags: "The ‘universal break-up criterion’ of hot flowing lava", , Lava fountains at Kilauea in Hawaii created a spatter cone which was estimated to be 180 feet tall., Low-viscosity lava is the red-hot flowing type one might see at Hawaii’s famed Kilauea volcano., , Tool lets scientists examine changing behavior of low-viscosity lava., Vulcanology   

    From Rice University: “The ‘universal break-up criterion’ of hot, flowing lava” 

    Rice U bloc

    From Rice University

    August 30, 2019
    Jade Boyd

    Tool lets scientists examine changing behavior of low-viscosity lava.

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    Thomas Jones is a Rice Academy Postdoctoral Fellow in Rice University’s Department of Earth, Environmental and Planetary Sciences. (Photo courtesy of T. Jones)

    Thomas Jones’ “universal break-up criterion” won’t help with meltdowns of the heart, but it will help volcanologists study changing lava conditions in common volcanic eruptions.

    Jones, of Rice University, studies the behavior of low-viscosity lava, the runny kind that’s found at most volcanoes. About two years ago, he began a series of lab experiments and field observations that provided the raw inputs for a new fluid dynamic model of lava break-up. The work is described in a paper in Nature Communications.

    Low-viscosity lava is the red-hot, flowing type one might see at Hawaii’s famed Kilauea volcano, and Jones said it usually behaves in one of two ways.

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    Lava fountains at Kilauea in Hawaii created a spatter cone, which was estimated to be 180 feet tall in this June 2018 photo. (Image courtesy of U.S. Geological Survey)

    “It can bubble or spew out, breaking into chunks that spatter about the vent, or it can flow smoothly, forming lava streams that can rapidly move downhill,” he said.

    But that behavior can sometimes change quickly during the course of an eruption, and so can the associated dangers: While spattering eruptions throw hot lava fragments into the air, lava flows can threaten to destroy whole neighborhoods and towns.

    Jones’ model, the first of its kind, allows scientists to calculate when an eruption will transition from a spattering spray to a flowing stream, based upon the liquid properties of the lava itself and the eruption conditions at the vent.

    Jones said additional work is needed to refine the tool, and he looks forward to doing some of it himself.

    “We will validate this by going to an active volcano, taking some high-speed videos and seeing when things break apart and under what conditions,” he said. “We also plan to look at the effect of adding bubbles and crystals, because real magmas aren’t as simple as the idealized liquid in our mathematical model. Real magmas can also have bubbles and crystals in them. I’m sure those will change things. We want to find out how.”

    Jones said pairing the new model with real-time information about a lava’s liquid properties and eruption conditions could allow emergency officials to predict when an eruption will change style and become a hazard to at-risk communities.

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    Lava from a fountain on Hawaii’s Kilauea volcano flows over a spillway into an established channel in June 2018. (Image courtesy of U.S. Geological Survey)

    “We want to use this as a forecasting tool for eruption behavior,” he said. “By developing a model of what’s happening in the subsurface we can then watch for indications that it’s about to cross the tipping point and change behavior.”

    The study was co-authored by C.D. Reynolds of the University of Birmingham in the United Kingdom and S.C. Boothroyd of Durham University, also in the UK. The research was supported by the UK’s National Environment Research Council and Rice University.

    See the full article here .


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    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 2:53 pm on August 13, 2019 Permalink | Reply
    Tags: "Jurassic world of volcanoes found in central Australia", , , The Cooper-Eromanga Basins., The discovery raises the prospect that more undiscovered volcanic worlds reside beneath the poorly explored surface of Australia., The volcanoes developed in the Jurassic period between 180 and 160 million years ago and have been subsequently buried beneath hundreds of meters of sedimentary – or layered – rocks., They’ve called the volcanic region the Warnie Volcanic Province with a nod to Australian cricket legend Shane Warne., University of Aberdeen, Vulcanology   

    From University of Aberdeen: “Jurassic world of volcanoes found in central Australia” 

    U Aberdeen bloc

    From University of Aberdeen

    13 August 2019

    An international team of subsurface explorers from the University of Aberdeen and University of Adelaide have discovered a ‘Jurassic World’ of around 100 ancient volcanoes buried deep beneath Australia’s largest onshore oil and gas producing region.

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    The volcanoes developed between 180 and 160 million years ago, and have been buried beneath hundreds of meters of sedimentary – or layered – rocks.

    The Cooper-Eromanga Basins – a dry and barren landscape located in the north-eastern corner of South Australia and south-western corner of Queensland – has seen about 60 years of petroleum exploration and production, however this ancient Jurassic volcanic underground landscape has gone largely unnoticed.

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    Cooper/ Eromanga Basin. Blue Energy

    The volcanoes developed in the Jurassic period, between 180 and 160 million years ago, and have been subsequently buried beneath hundreds of meters of sedimentary – or layered – rocks.

    Published in the journal Gondwana Research, the researchers used advanced subsurface imaging techniques, analogous to medical CT scanning, to identify the plethora of volcanic craters and lava flows, and the deeper magma chambers that fed them.

    They’ve called the volcanic region the Warnie Volcanic Province, with a nod to Australian cricket legend Shane Warne.

    In Jurassic times, the researchers say, the area would have been a landscape of craters and fissures, spewing hot ash and lava into the air, and surrounded by networks of river channels, evolving into large lakes and coal-swamps.

    “While the majority of Earth’s volcanic activity occurs at the boundaries of tectonic plates, or under the Earth’s oceans, this ancient Jurassic world developed deep within the interior of the Australian continent,” said co-author Associate Professor Simon Holford, from the University of Adelaide’s Australian School of Petroleum.

    “Its discovery raises the prospect that more undiscovered volcanic worlds reside beneath the poorly explored surface of Australia.”

    The research was carried out by Jonathon Hardman, then a PhD student at the University of Aberdeen, as part of the Natural Environment Research Council Centre for Doctoral Training in Oil and Gas.

    The researchers say that Jurassic-aged sedimentary rocks bearing oil, gas and water have been economically important for Australia, but this latest discovery suggests a lot more volcanic activity in the Jurassic period than previously supposed.

    “The Cooper-Eromanga Basins have been substantially explored since the first gas discovery in 1963,” said co-author Associate Professor Nick Schofield, from the University of Aberdeen’s Department of Geology and Petroleum Geology.

    “This has led to a massive amount of available data from underneath the ground but the volcanics have never been properly understood in this region until now. It changes how we understand processes that have operated in Earth’s past.”

    The researchers have named their discovery the Warnie Volcanic Province after one of the drill holes that penetrated Jurassic volcanic rocks (Warnie East-1, itself named after a nearby waterhole), but also in recognition of the explosive talent of former Australian cricketer Shane Warne.

    “We wrote much of the paper during a visit to Adelaide by the Aberdeen researchers, when a fair chunk was discussed and written at Adelaide Oval during an England vs Cricket Australia XI match in November 2017,” explained Associate Professor Holford.

    “Inspired by the cricket, we thought Warnie a good name for this once fiery region.”

    See the full article here .

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    U Aberdeen Campus

    Founded in 1495 by William Elphinstone, Bishop of Aberdeen and Chancellor of Scotland, the University of Aberdeen is Scotland’s third oldest and the UK’s fifth oldest university.

    William Elphinstone established King’s College to train doctors, teachers and clergy for the communities of northern Scotland, and lawyers and administrators to serve the Scottish Crown. Much of the King’s College still remains today, as do the traditions which the Bishop began.

    King’s College opened with 36 staff and students, and embraced all the known branches of learning: arts, theology, canon and civil law. In 1497 it was first in the English-speaking world to create a chair of medicine. Elphinstone’s college looked outward to Europe and beyond, taking the great European universities of Paris and Bologna as its model.
    Uniting the Rivals

    In 1593, a second, Post-Reformation University, was founded in the heart of the New Town of Aberdeen by George Keith, fourth Earl Marischal. King’s College and Marischal College were united to form the modern University of Aberdeen in 1860. At first, arts and divinity were taught at King’s and law and medicine at Marischal. A separate science faculty – also at Marischal – was established in 1892. All faculties were opened to women in 1892, and in 1894 the first 20 matriculated female students began their studies. Four women graduated in arts in 1898, and by the following year, women made up a quarter of the faculty.

    Into our Sixth Century

    Throughout the 20th century Aberdeen has consistently increased student recruitment, which now stands at 14,000. In recent years picturesque and historic Old Aberdeen, home of Bishop Elphinstone’s original foundation, has again become the main campus site.

    The University has also invested heavily in medical research, where time and again University staff have demonstrated their skills as world leaders in their field. The Institute of Medical Sciences, completed in 2002, was designed to provide state-of-the-art facilities for medical researchers and their students. This was followed in 2007 by the Health Sciences Building. The Foresterhill campus is now one of Europe’s major biomedical research centres. The Suttie Centre for Teaching and Learning in Healthcare, a £20m healthcare training facility, opened in 2009.

     
  • richardmitnick 8:51 am on August 12, 2019 Permalink | Reply
    Tags: "Crystal Clocks Serve as Stopwatch for Magma Storage and Travel Times", , , , , The mineral’s composition changes creating a kind of crystal clock., The team used a volcanic mineral called spinel as a crystal stopwatch., , Vulcanology   

    From U Cambridge via Eos: “Crystal Clocks Serve as Stopwatch for Magma Storage and Travel Times” 

    U Cambridge bloc

    From University of Cambridge

    Via

    AGU
    Eos news bloc

    Eos

    8.12.19
    Mary Caperton Morton

    Magma stored for 1,000 years in an Icelandic volcano journeyed to the surface in just 4 days.

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    The 2014–2015 eruption of Iceland’s Holuhraun lava field had an eruption style similar to the Borgarhraun eruption of Iceland’s Theistareykir volcano, which took place 10,000 years ago. Credit: Euan J. F. Mutch

    Volcanic eruptions are just the tip of the iceberg: Hidden deep below ground, the preeruption behavior and movements of magma remain largely mysterious. Two new studies centered around a volcano in Iceland are shedding light on how long magma was stored deep underground and how long it took to travel to the surface before erupting, information that may be used to improve existing models of complex magmatic systems.

    Geophysical monitoring methods can see only so deep beneath the surface of Earth, so to figure out what is happening deep inside a volcano, “you have to be a geological detective,” said Euan Mutch, an igneous petrologist at the University of Cambridge in the United Kingdom and lead author on both of the new studies, published in Science and Nature Geoscience.

    Mutch and colleagues at the University of Cambridge focused on the Borgarhraun eruption of Theistareykir, a volcano in northern Iceland, which took place around 10,000 years ago. Previous studies have shown the magma that fed this eruption came directly from the Mohorovičić discontinuity (the Moho), where Earth’s crust meets its mantle, at a depth of about 24 kilometers—far deeper than geophysical methods can see clearly.

    To determine how long the magma was stored at the Moho before erupting, the team used a volcanic mineral called spinel as a crystal stopwatch.

    “The elements in the crystal want to be in equilibrium with the surroundings,” Mutch explained.

    As the elements equilibrate by diffusing out of the spinel, the mineral’s composition changes, creating a kind of crystal clock. Using known diffusion rates for aluminum and chromium, the team was able to determine how long the minerals were stored in the melt before it erupted, in this case about a thousand years, they wrote in Science.

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    Mineral maps like this one show areas of concentrated aluminum in yellow and lower concentrations in red and black. The process of diffusion from high to low concentration can be used to estimate how long the crystal remained in the magma chamber before erupting. Credit: Euan J. F. Mutch

    In the Nature Geoscience study, Mutch and colleagues used a similar diffusion modeling technique on olivine crystals to show that the magma ascended from the Moho to the surface in as little as 4 days, at a rate of 0.02 to 0.1 meter per second.

    The two studies represent some of the first evidence of magmatic timescales for eruptions originating in the deep crust at the Moho boundary, said David Neave, a petrologist at the University of Manchester in the United Kingdom who was not involved in either of the new studies.

    “A lot of progress has been made understanding timescales of shallower volcanoes, but these are the first studies to estimate how long magma is stored in the deep crust before it erupts,” Neave said. “That’s crucial new information.”

    Diffusion modeling is not a new technique. The methods have been around for at least 10 years, Neave said, but Mutch and colleagues “were very clever in working out the uncertainties and arrived at much more precise estimates for these timescales than previous groups have been able to do.”

    The findings also lend support to a growing body of research suggesting that magmatic systems can be much more complex than the textbook model of a volcano fed directly from a single bulbous magma chamber, said Stephen Sparks, a volcanologist at the University of Bristol in the United Kingdom who was not involved in either of the new studies.

    “Their results contribute to the evidence that supports vertically extensive transcrustal magma systems,” Sparks said. The study does not introduce any fundamentally new concepts but “supports this emerging new paradigm. The paper is amongst the most thorough and convincing published so far.”

    Applying the Techniques to Other Volcanoes

    Whether the 1,000-year timescales for magma storage and mere days of travel to the surface are typical of other volcanoes or unique to Theistareykir is unknown, Mutch said. The next steps will be to apply the same diffusion modeling techniques to other eruptions.

    Crystal clocks can be used at a variety of volcano types, not just the basaltic volcanoes found in Iceland, Neave said.

    “Most volcanoes are ultimately underlain by basaltic materials, even if they’re erupting rhyolite or andesite at the surface like at the Cascades volcanoes [in the United States],” he said. “I think this approach will prove to be widely applicable to a range of volcanic settings.”

    The findings may ultimately aid in developing more accurate magmatic and eruption models as well as improving volcanic hazard forecasts, Mutch said. The Nature Geoscience paper in particular showed a link between the magma’s rate of ascent and the release of carbon dioxide, which could be used to predict an impending eruption.

    “At the ascent rates estimated for the Borgarhraun magma, an increase in carbon dioxide flux at the surface would only be detected at most 2 days before the eruption,” Mutch said. However, other volcanic systems may offer more lead time: “This threshold will be different for magmas with different carbon contents and that are stored at different depths before eruption.”

    See the full article here .

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

    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
  • richardmitnick 2:11 pm on August 7, 2019 Permalink | Reply
    Tags: "Witnessing the Birth of a Crater Lake Where Lava Just Flowed", Although the rocks there are now cool enough to permit liquid water to exist they remain scorching hot., As of now there are three pools each growing in size and likely to coalesce., Crucially the crater floor which progressively collapsed during the 2018 eruption is now 167 feet below the water table., It’s possible that we are witnessing the birth of a full-blown crater lake in a pit once ravaged by fire., Last spring Hawaii’s Kilauea volcano began its most destructive eruption in recorded history., , The water was first spotted toward the end of July when helicopters passing over Halema’uma’u saw a green anomaly., Vulcanology, Water is at the bottom of Halema‘uma‘u where three small ponds have begun to merge.   

    From The New York Times: “Witnessing the Birth of a Crater Lake Where Lava Just Flowed” 

    New York Times

    From The New York Times

    Aug. 7, 2019
    Robin George Andrews

    The magma mysteriously drained from the crevice last year, and now scorching pools of water are bubbling up from below.

    1
    A view of Halema‘uma‘u from the summit of Kilauea, where a bright pool of lava at the center of the crater had existed for nearly 10 years. Credit C. Parcheta/U.S. Geological Survey

    Last spring, Hawaii’s Kilauea volcano began its most destructive eruption in recorded history.

    2

    On May 2, as its underlying magma supply headed to the mountain’s lower east rift zone, and a lava lake within the Halema’uma’u summit crater that had been there for 10 years began to rapidly drain. A week later, this pool of molten fury had vanished from sight.

    Now, long after the last embers of that eruption faded, the lake is being replaced by water that is likely rising from below.

    A single green pool was spotted at the base of the gargantuan crater in late July. As of now, there are three pools, each growing in size and likely to coalesce.

    3
    Water at the bottom of Halema‘uma‘u, where three small ponds have begun to merge. The pond in the foreground, the largest, is about 50 feet across. Credit M. Patrick/U.S. Geological Survey

    4
    A view of the bottom taken with a thermal crater. Credit M. Patrick/U.S. Geological Survey

    Only time will tell, but it’s possible that we are witnessing the birth of a full-blown crater lake in a pit once ravaged by fire.

    Some Hawaiian oral histories may suggest that water was present in Halema’uma’u around the year 1500, and again around 1650, says Don Swanson, scientist emeritus at the United States Geological Survey’s Hawaiian Volcano Observatory. But written observations of the summit crater only go back to 1823, so this is the first time it can be definitively said to contain water in the last couple of centuries.

    The water was first spotted toward the end of July, when helicopters passing over Halema’uma’u saw a green anomaly. Some thought it might be an illusion created by sulfur minerals or algae But an Aug. 1 flyover by scientists at the observatory confirmed a pool of water.

    Although the rocks there are now cool enough to permit liquid water to exist, they remain scorching hot. The water, acidified by escaping magmatic gas, is about 158 degrees Fahrenheit. It is flanked by several fumaroles, vents unleashing volcanic gas at temperatures as high as 392 degrees.

    It may seem intuitive that an empty crater is simply filling up with rainwater, but Dr. Swanson says that’s unlikely. “We’ve had a year with a lot of rain and the pond only showed up recently,” he said.

    Crucially, the crater floor, which progressively collapsed during the 2018 eruption, is now 167 feet below the water table. That means the liquid here is probably groundwater, migrating in sideways and collecting within the crater.

    To confirm its provenance, the scientists will need to gather samples. If the water is old, that would suggest it had been underground for a considerable length of time and hasn’t recently fallen from the sky.

    Getting those samples will require someone with a good aim, because it’s too dangerous to obtain them on foot. Scientists want to fly a helicopter over Halema’uma’u and scoop some up using a bucket attached to a 1,640-foot-long rope.

    Dr. Swanson, who reported the discovery in a blog post on the Hawaiian Volcano Observatory’s website this month, explained that this crater filled with lava where the water is now pooling has come and gone in the past. From 1823, it existed until the late-1890s, when it disappeared before springing up again in the early 1900s. Then, it was present until explosions rocked the summit in 1924. It vanished yet again until 2008, after which it grew and persisted until last year.

    “There are no facts about the future,” said Dr. Swanson, but there is a good chance that magma will slowly rise up the volcano’s throat, reoccupy the crater and form a new lava lake. Based on its past behavior, if it does return, it will only take a few years to do so, and the pooling water won’t last long.

    “Eventually,” said Dr. Swanson, “the volcano will win the battle.”

    Right now, the depth of the water isn’t known, but if it’s dozens of feet below the surface, there could be fireworks. Water and magma can make for an unpredictable, explosive mixture, and a deeper water column makes that violent interaction more likely.

    Fortunately, any blasts will be confined to the summit crater itself. “There is a greater potential for explosions than we’d realized before,” Dr. Swanson said, “but this is not going to affect public safety.”

    See the full article here .

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  • richardmitnick 11:06 am on August 6, 2019 Permalink | Reply
    Tags: "Geoengineering versus a volcano", , , , , Vulcanology   

    From Carnegie Institution for Science: “Geoengineering versus a volcano” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    August 05, 2019

    1
    A photo of the eruption of Mount Pinatubo by Jackson K., courtesy of USGS.

    Major volcanic eruptions spew ash particles into the atmosphere, which reflect some of the Sun’s radiation back into space and cool the planet. But could this effect be intentionally recreated to fight climate change? A new paper in Geophysical Research Letters investigates.

    Solar geoengineering is a theoretical approach to curbing the effects of climate change by seeding the atmosphere with a regularly replenished layer of intentionally released aerosol particles. Proponents sometimes describe it as being like a “human-made” volcano.

    “Nobody likes the idea of intentionally tinkering with our climate system at global scale,” said Carnegie’s Ken Caldeira. “Even if we hope these approaches won’t ever have to be used, it is really important that we understand them because someday they might be needed to help alleviate suffering.”

    He, along with Carnegie’s Lei Duan (a former student from Zhejiang University), Long Cao of Zhejiang University, and Govindasamy Bala of the Indian Institute of Science, set out to compare the effects on the climate of a volcanic eruption and of solar geoengineering. They used sophisticated models to investigate the impact of a single volcano-like event, which releases particulates that linger in the atmosphere for just a few years, and of a long-term geoengineering deployment, which requires maintaining an aerosol layer in the atmosphere.

    They found that regardless of how it got there, when the particulate material is injected into the atmosphere, there is a rapid decrease in surface temperature, with the land cooling faster than the ocean.

    However, the volcanic eruption created a greater temperature difference between the land and sea than did the geoengineering simulation. This resulted in different precipitation patterns between the two scenarios. In both situations, precipitation decreases over land—meaning less available water for many people living there—but the decrease was more significant in the aftermath of a volcanic eruption than it was in the geoengineering case.

    “When a volcano goes off, the land cools substantially quicker than the ocean. This disrupts rainfall patterns in ways that you wouldn’t expect to happen with a sustained deployment of a geoengineering system,” said lead author Duan.

    Overall, the authors say that their results demonstrate that volcanic eruptions are imperfect analogs for geoengineering and that scientists should be cautious about extrapolating too much from them.

    “While it’s important to evaluate geoengineering proposals from an informed position, the best way to reduce climate risk is to reduce emissions,” Caldeira concluded.

    See the full article here .


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    Carnegie Institution of Washington Bldg

    Carnegie Institution for Science

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile


    Carnegie Las Campanas 2.5 meter Irénée Dupont telescope, Atacama Desert, over 2,500 m (8,200 ft) high approximately 100 kilometres (62 mi) northeast of the city of La Serena,Chile


    Carnegie Institution Swope telescope at Las Campanas, Chile, 100 kilometres (62 mi) northeast of the city of La Serena. near the north end of a 7 km (4.3 mi) long mountain ridge. Cerro Las Campanas, near the southern end and over 2,500 m (8,200 ft) high, at Las Campanas, Chile

    [/caption]

     
  • richardmitnick 12:33 pm on August 2, 2019 Permalink | Reply
    Tags: "Earth’s volcanic ‘hot spots’ are in constant motion", , , , , Vulcanology   

    From University of Rochester and Futurity: “Earth’s volcanic ‘hot spots’ are in constant motion” 

    U Rochester bloc

    From University of Rochester

    and

    From Futurity

    1
    (Credit: Marc Szeglat/Unsplash)

    August 2nd, 2019
    Lindsey Valich-Rochester

    Scientists have long considered volcanic hot spots, like those that created the Hawaiian Islands, stationary points, but a new study finds they are actually in constant motion.

    The findings, which appear in in Nature Communications, solve a major debate about the origin of the large-scale structure of the Earth’s surface and deep interior.

    The Earth’s lithosphere is the outermost shell of our planet, composed of seven major puzzle pieces known as tectonic plates. While today each of the tectonic plates roughly encompasses one of the seven continents and the Pacific Ocean, scientists believe the pieces once fit together to form supercontinents.

    Earth’s last supercontinent, Pangea, began to break apart about 175 million years ago. Much of the Earth’s seismic activity, including earthquakes and volcanoes, occurs at the boundaries of the tectonic plates.

    But there are other regions on Earth characterized by volcanic activity, independent of the plate boundaries. Researchers refer to these areas as hot spots. Scientists believe hot spots develop above abnormally hot upwellings of magma in the Earth’s mantle called mantle plumes.

    Although researchers can’t travel to the mantle to observe these processes, they are able to infer hot spots because of the volcanism that develops when the magma pushes through the lithosphere. The most active hot spots include those beneath Yellowstone, the Galapagos Islands, Iceland, and Hawaii.

    4
    Molten lava on the surface of the Big Island of Hawaii. New data analyses from Rochester researchers show that the volcanic hot spots that helped form the Hawaiian islands are not fixed, but are in constant motion. (Getty Images photo)

    Volcanic hot spots on the move

    Scientists widely accepted the theory of plate tectonics in the 1960s, but “deciphering the past motion of Earth’s tectonic plates and linking these motions to deeper processes within the Earth is an ongoing challenge in the geosciences,” says John Tarduno, a professor of earth and environmental sciences at the University of Rochester.

    For decades after the plate tectonics revolution, researchers thought hot spots stayed fixed, providing a reference frame to measure the motion of the Earth’s plates.

    An iconic illustration of this idea was the 60-degree bend in the chain of islands that make up Hawaii. Researchers believed an assembly line-like process created the Hawaiian Islands: an island would form over a hot spot, the motion of the plate would move the island off the hot spot, and the hot spot would remain in place and generate a new island.

    In 2001, Tarduno and colleagues collected samples of rocks and sediment via scientific ocean drilling in Hawaii’s Emperor Seamounts—undersea, extinct volcanoes in the Pacific Ocean. By studying the magnetism locked in the ancient samples—a field known as paleomagnetism—the researchers determined that the hot spot beneath Hawaii was not fixed but had moved. This painted a picture more consistent with an actively convecting and constantly churning mantle.

    Despite this evidence, however, controversy over the fixity of hot spots continued.

    2
    Satellite composition of the Hawaiian islands. (Credit: NASA/Goddard Space Flight Center)

    Slow traveling seismic waves

    The debate heightened when researchers recognized that many hot spots were rooted in one of two large regions above the core-mantle boundary: one region under Africa and the other under the Pacific. Seismologists’ research indicated these were regions, known as large low-shear-velocity provinces (LLSVPs), where seismic waves travel slowly. The slow speed meant the regions were unusually hot or chemically different from surrounding rock.

    Some scientists believe LLSVPs are relics of plate subduction, where one plate moves downward into the mantle beneath another place, suggesting that LLSVPs are constantly moving. Other scientists believe LLSVPs are stationary and formed from a primordial formation, dating to the earliest processes that shaped the planet.

    The new analyses including modeling, geochemistry, and paleomagnetism, suggest LLSVPs are in motion, relics of subduction that has been taking place since the breakup of Pangea.

    “LLSVPs are clearly ancient, greater than 100 million years old, but some researchers have claimed they are also fixed and thus can be used as a reference frame for plate motion,” Tarduno says. “The new analyses suggest that LLSVPs can attract mantle plumes until the LLSVPs and the mantle plumes merge.”

    The researchers also discovered that LLSVPs can undergo large-scale motion comparable in speed to the motion of the tectonic plates. This provides even more evidence that it was the motion of hot spots—and not their fixity—that caused the bend in the Hawaiian Islands.

    What are hot spots?

    The earth’s lithosphere is the outermost shell of our planet, composed of seven major puzzle pieces known as tectonic plates. While today each of the tectonic plates roughly encompasses one of the seven continents and the Pacific Ocean, scientists believe the pieces once fit together to form supercontinents. Earth’s last supercontinent, Pangea, began to break apart about 175 million years ago. Much of the earth’s seismic activity, including earthquakes and volcanoes, occurs at the boundaries of the tectonic plates.

    But there are other regions on earth characterized by volcanic activity, independent of the plate boundaries. Researchers refer to these areas as hot spots. Hot spots are thought to develop above abnormally hot upwellings of magma in the earth’s mantle called mantle plumes. Although researchers cannot travel to the mantle to observe these processes, they are able to infer hot spots because of the volcanism that develops when the magma pushes through the lithosphere. The most active hot spots include those beneath Yellowstone, the Galapagos Islands, Iceland, and Hawaii.

    Large regions of hot spots

    The debate was heightened when researchers recognized that many hot spots were rooted in one of two large regions above the core-mantle boundary: one region under Africa and the other under the Pacific. Research by seismologists indicated these were regions, known as large low-shear-velocity provinces (LLSVPs), where seismic waves travel slowly. The slow speed meant the regions were unusually hot or chemically different from surrounding rock.

    Some scientists believe LLSVPs are relics of plate subduction, where one plate moves downward into the mantle beneath another place, suggesting that LLSVPs are constantly moving. Other scientists believe LLSVPs are stationary and formed from a primordial formation, dating to the earliest processes that shaped the planet.

    The new analyses conducted by Tarduno and his team, including modeling, geochemistry, and paleomagnetism, suggest LLSVPs are in motion, relics of subduction that has been taking place since the breakup of Pangea.

    “LLSVPs are clearly ancient, greater than 100 million years old, but some researchers have claimed they are also fixed and thus can be used as a reference frame for plate motion,” Tarduno says. “The new analyses suggest that LLSVPs can attract mantle plumes until the LLSVPs and the mantle plumes merge.”

    The researchers also discovered that LLSVPs can undergo large-scale motion comparable in speed to the motion of the tectonic plates. This provides even more evidence that it was the motion of hot spots—and not their fixity—that caused the bend in the Hawaiian Islands.

    See the full article here .

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    U Rochester Campus

    The University of Rochester is one of the country’s top-tier research universities. Our 158 buildings house more than 200 academic majors, more than 2,000 faculty and instructional staff, and some 10,500 students—approximately half of whom are women.

    Learning at the University of Rochester is also on a very personal scale. Rochester remains one of the smallest and most collegiate among top research universities, with smaller classes, a low 10:1 student to teacher ratio, and increased interactions with faculty.

     
  • richardmitnick 7:52 am on August 1, 2019 Permalink | Reply
    Tags: "When it comes to volcanoes Monte Carlo may save Naples", , , , , Monte Carlo simulations, Vulcanology   

    From COSMOS Magazine: “When it comes to volcanoes, Monte Carlo may save Naples” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    01 August 2019
    Barry Keily

    Researchers combine stress and statistics to refine eruption risk.

    1
    Monte Nuovo is the vent of one of the smallest eruptions at Campi Flegrei, Italy. Credit Mauro Antonio Di Vito.

    Contrary to cartoon depictions, volcanoes rarely erupt more than once from the same hole. In some cases, explosive ejections of magma, ash and rocks can kick off a substantial distance away from previous hotspots.

    The ability to identify with any degree of precision likely eruption sites is a matter that has been the subject of intensive research for decades, but to date evidence has been substantially, and sometimes catastrophically, at odds with predictions.

    Now, however, a team led by Eleonora Rivalta from the GFZ German Research Centre for Geosciences, in Potsdam, Germany, has come up with a new and promising approach that marries physics and mathematics.

    Although the method has yet to be real-world tested, the researchers report that a retrospective comparison using eruptions that took place over centuries at Italy’s densely populated Campi Flegrei volcanic field, which includes the city of Naples, has shown encouraging results.

    The problem of predicting exact eruption spots is at its keenest in the case of calderas – volcanoes on which the summit has collapsed, leaving craters that can be as big as 100 kilometres in diameter.

    “Calderas have fed some of the most catastrophic eruptions on Earth and are extremely hazardous,” Rivalta and colleagues write in the journal Science Advances.

    “However, their eruptions are generally few and far apart; thus, hazard is often underestimated by the local population, which, at some calderas, approaches one million.”

    Predicting when and where eruptions could happen, the researchers add, is thus regarded as “extremely challenging”.

    The difficulty arises because it is impossible to test the assumptions on which current models rest.

    Hazard estimation proceeds from the not unreasonable idea that future eruptions are likely to occur in close proximity to the sites of past ones.

    However, this presumes that the distribution of past volcanic vents indicates areas of geologic weakness. Such a presumption, the researchers write, is not supported by the evidence.

    A second approach concedes an unknown mechanism determines the path which ascending magma takes but assumes there is a higher probability of a new vent opening near clusters of old ones than in somewhere unscarred.

    This method is valid, Rivalta and colleagues confirm, inasmuch as the probabilities are borne out by the history of eruptions on Campi Flegrei, but because these events don’t happen very often, the number of available data points is insufficient to produce predictions with a useful degree of precision.

    To overcome these issues, the researchers turned to the physics of magma flows, a field that has been comprehensively studied ever since Canadian geologist Reginal Aldworth Daly published the first research on it in the late nineteenth century.

    They combined this with a statistical approach known as the Monte Carlo method, wherein calculations of events are run thousands of times in order to encompass the possible influence of unpredictable variables.

    Monte Carlo simulations are widely used for risk analysis in fields as diverse as insurance, mining and finance.

    Rivalta and colleagues based the limits of their calculations on existing data describing the stresses present, and already measured, across Campi Flegrei. The results showed that previous assumptions regarding the importance of existing faults in influencing magma flow were incorrect.

    Faults certainly play a role, but it is less significant than assumed, and less direct – magma is likely to move at a tangent to them rather than mirror them.

    Instead, the results showed that it was possible to predict the direction of magma flows as long as the stresses involved and the exact location of the subterranean magma chamber were known – matters that the researchers quickly concede are often “very poorly constrained”.

    Nevertheless, they conclude, their method produces more accurate predictions – at least retrospectively – than existing ones.

    “We show that magma trajectories, and thus eruptive vent locations, are so sensitive to stress variations that the previous vent locations at a volcano can be used to constrain the stress field to a sufficient degree of accuracy to render reliable physics-based vent forecasts possible,” they write.

    See the full article here .


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  • richardmitnick 12:23 pm on July 31, 2019 Permalink | Reply
    Tags: "The Hidden Volcanoes of Central Oregon", , , , , Mystery volcano: the Tumalo Volcanic Center, Vulcanology   

    From Discover Magazine: “The Hidden Volcanoes of Central Oregon” 

    DiscoverMag

    From Discover Magazine

    July 31, 2019
    Erik Klemetti

    1
    A river channel filled with cliff swallow holes carved into the Desert Spring Tuff. Image by Erik Klemetti

    Earlier this month, I spent a little over a week exploring one of the biggest mysteries in then Cascade Range. These volcanoes span from Northern California into British Columbia and host such well-known peaks as Mount St. Helens, Hood and Shasta. Yet, some of the largest eruptions over the past million years in the Cascades may have come from volcanoes that are totally hidden from view today. One of those mystery volcanoes is the Tumalo Volcanic Center.

    I’ve been fascinated by the TVC since I was in graduate school. We would take field trips from Oregon State University to visit the area around Bend in central Oregon. Now, if you’ve never been to Bend, you’re missing a true volcanic wonderland. The city is built on layer after layer of volcanic rock that go back millions of years.

    Some of the volcanic features are very young (geologically-speaking), having formed in the past few thousand years. This includes basaltic and rhyolite lava from from Newberry, steep cinder cones like Mt. Bachelor, sticky rhyolite domes like the Devil’s Hills along with the ash and pumice from the TVC.

    This project in the TVC is part a National Science Foundation grant that was awarded to me and Adam Kent (Oregon State University) to pick apart, date and unravel the processes that formed the massive explosive eruptions (and smaller stuff). We looked at a lot of volcanic material over our field work, but right now, I’m going to focus on some cool stuff we saw in the Oregon State University Cascades campus pumice quarry.

    2
    An annotated image of one of the walls in the OSU-C quarry. The three main TVC units seen are the Desert Spring Tuff, Bend Pumice and Tumalo Tuff. The only one missing is the Shevlin Park Tuff. Image and annotation: Erik Klemetti

    The wall pictured above captures three of the “big 4” eruption deposits from the TVC. The oldest we know of is the Desert Spring Tuff (at the bottom). It is pretty tough because it has become partially welded, when the volcanic glass remelts after the ash and debris lands on the ground.

    Above that (thus younger) are the Bend Pumice and Tumalo Tuff. These two might be consecutive eruptions — a one-two punch of a big pumice fall followed by pyroclastic flows. Image a tall ash plume from a massive explosive eruption that rained pumice across the landscape and then collapse, sending searing hot flows of pumice, ash and debris away from the volcano.

    Both units are pretty loose unlike the Desert Spring Tuff. You can walk up to the Bend Pumice and pluck individual pumice chunks right out. You can see a close up of some of the pumice from a smaller pumice fall below the Bend Pumice (also seen on the image above). These might be little blasts that preceded the Bend Pumice by days, weeks or more. In the Bend Pumice, the pumice changes sizes as well and this recorded how the force of the eruption might have changed over the duration of the eruption.

    3
    Layers of pumice in the Bend Pumice, each potentially marking a pulse of the main eruption or blasts that happened before the main event. Image by Erik Klemetti.

    A few details to note: You might notice the top of the Tumalo Tuff (above) looks less like a pile of rubble. That’s because it may have been altered by vapor percolating through the ash and pumice, “gluing” it together into a wall. Also, at the bottom of the Tumalo Tuff is a lag deposit made of larger chunks of pumice that may have been deposited as a pyroclastic flow slowed down.

    The pumice erupted from the TVC actually did have some real monetary value. Pumice was and is mined from various locations around Bend for decades as an abrasive and some of the rocks that might be part of the TVC were also used a good, local building stone. One of these quarries is now part of the OSU-C campus, but as the school grows, they need more land, so the quarry is going to be mostly filled to make way for new structures.

    This is just a taste of the Tumalo Volcano Center and over the next few years, we hope to find out a lot more about this hidden volcano in Central Oregon. Although the likelihood of it reawakening is very small, it is never a bad idea to understand the volcanic history of a region growing as fast as Deschutes County and Bend.

    See the full article here .

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