Tagged: Vulcanology Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 8:38 am on May 17, 2019 Permalink | Reply
    Tags: "From Earth’s deep mantle, Bermuda has a unique volcanic past., , Geochemical signatures, , scientists discover a new way volcanoes form", , The mantle’s transition zone – between 250 to 400 miles beneath our planet’s crust, The peculiar and extreme isotopes measured in the Bermuda lava core had not been observed before., There is enough water in the transition zone to form at least three oceans according to Gazel but it is the water that helps rock to melt in the transition zone., Vulcanology   

    From Cornell Chronicle: “From Earth’s deep mantle, scientists discover a new way volcanoes form” 

    From Cornell Chronicle

    May 15, 2019
    Blaine Friedlander
    bpf2@cornell.edu

    1
    Bermuda has a unique volcanic past. About 30 million years ago, a disturbance in the mantle’s transition zone supplied the magma to form the now-dormant volcanic foundation on which the island sits. Wendy Kenigsberg/Clive Howard – Cornell University, modified from Mazza et al. (2019)

    Far below Bermuda’s pink sand beaches and turquoise tides, Cornell geoscientists have discovered the first direct evidence that material from deep within Earth’s mantle transition zone – a layer rich in water, crystals and melted rock – can percolate to the surface to form volcanoes.

    2
    In a cross-polarized microscopic slice of a core sample, the blue and yellow crystal is titanium-augite, surrounded by a ground mass of minerals, which include feldspars, phlogopite, spinel, perovskite and apatite. This assemblage suggests that the mantle source – rich in water – produced this lava. Gazel Lab/Provided

    Scientists have long known that volcanoes form when tectonic plates (traveling on top of the Earth’s mantle) converge, or as the result of mantle plumes that rise from the core-mantle boundary to make hotspots at Earth’s crust.

    The tectonic plates of the world were mapped in 1996, USGS.

    But obtaining evidence that material emanating from the mantle’s transition zone – between 250 to 400 miles beneath our planet’s crust – can cause volcanoes to form is new to geologists.

    “We found a new way to make volcanoes. This is the first time we found a clear indication from the transition zone deep in the Earth’s mantle that volcanoes can form this way,” said senior author Esteban Gazel, Cornell associate professor in the Department of Earth and Atmospheric Sciences. The research published in Nature on May 15.

    “We were expecting our data to show the volcano was a mantle plume formation – an upwelling from the deeper mantle – just like it is in Hawaii,” Gazel said. But 30 million years ago, a disturbance in the transition zone caused an upwelling of magma material to rise to the surface, form a now-dormant volcano under the Atlantic Ocean and then form Bermuda.

    Using a 2,600-foot core sample – drilled in 1972, housed at Dalhousie University, Nova Scotia – co-author Sarah Mazza of the University of Münster, Germany, assessed the cross-section for signature isotopes, trace elements, evidence of water content and other volatile material. The assessment provided a geologic, volcanic history of Bermuda.

    “I first suspected that Bermuda’s volcanic past was special as I sampled the core and noticed the diverse textures and mineralogy preserved in the different lava flows,” Mazza said. “We quickly confirmed extreme enrichments in trace element compositions. It was exciting going over our first results … the mysteries of Bermuda started to unfold.”

    From the core samples, the group detected geochemical signatures from the transition zone, which included larger amounts of water encased in the crystals than were found in subduction zones. Water in subduction zones recycles back to Earth’s surface. There is enough water in the transition zone to form at least three oceans, according to Gazel, but it is the water that helps rock to melt in the transition zone.

    The geoscientists developed numerical models with Robert Moucha, associate professor of Earth sciences at Syracuse University, to discover a disturbance in the transition zone that likely forced material from this deep mantle layer to melt and percolate to the surface.

    Despite more than 50 years of isotopic measurements in oceanic lavas, the peculiar and extreme isotopes measured in the Bermuda lava core had not been observed before. Yet, these extreme isotopic compositions allowed the scientists to identify the unique source of the lava.

    “If we start to look more carefully, I believe we’re going to find these geochemical signatures in more places,” said co-author Michael Bizimis, associate professor at the University of South Carolina.

    Gazel explained that this research provides a new connection between the transition zone layer and volcanoes on the surface of Earth. “With this work we can demonstrate that the Earth’s transition zone is an extreme chemical reservoir,” he said. “We are now just now beginning to recognize its importance in terms of global geodynamics and even volcanism.”

    Said Gazel: “Our next step is to examine more locations to determine the difference between geological processes that can result in intraplate volcanoes and determine the role of the mantle’s transition zone in the evolution of our planet.”

    Gazel is a fellow at Cornell’s Atkinson Center for a Sustainable Future and a fellow at Cornell’s Carl Sagan Institute. In addition to Gazel, Mazza, Bizimis and Moucha, co-authors of “Sampling the Volatile-Rich Transition Zone Beneath Bermuda,” are Paul Béguelin, University of South Carolina; Elizabeth A. Johnson, James Madison University; Ryan J. McAleer, United States Geological Survey; and Alexander V. Sobolev, the Russian Academy of Sciences.

    The National Science Foundation provided funding for this research.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

    Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

    On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

     
  • richardmitnick 12:30 pm on May 14, 2019 Permalink | Reply
    Tags: , Bárðarbunga-Eruption at Holuhraun September 4 2014, , Vulcanology   

    From Eos: “More Than 30,000 Earthquakes Trace the Movement of Magma” 

    From AGU
    Eos news bloc

    From Eos

    5.14.19
    Katherine Kornei

    Seismometers near Iceland’s Bárðarbunga volcanic system pinpointed thousands of earthquakes in 2014–2015, revealing where molten rock was moving underground before any eruptions occurred.

    1
    Bárðarbunga-Eruption at Holuhraun, September 4, 2014, https://www.flickr.com/photos/41812768@N07/15146259395/

    2
    As Iceland’s Bárðarbunga volcanic system erupts in the background, researcher Jenny Woods downloads data from a seismometer. Image courtesy of Cambridge Volcano Seismology. Credit: Jenny Woods

    Accurate forecasting of volcanic eruptions is life-saving science: Millions of people worldwide live in the shadow of a volcano.

    Researchers have now analyzed precise records of tens of thousands of earthquakes in Iceland and produced one of the most detailed pictures of how seismicity traces the movement of magma deep underground. These kinds of measurements, which reveal the location of molten rock, can be used to better predict when and where eruptions will occur, the scientists suggest.

    Lucky Placement

    Robert White, a geophysicist at the University of Cambridge in the United Kingdom, admits he was lucky. He and his colleagues on the Cambridge Volcano Seismology team had already installed over 60 seismometers near Iceland’s Bárðarbunga volcanic system when magma began moving underground in 2014.

    The instrumentation was intended for a neighboring volcano, but White and his collaborators soon realized the seismometers were perfectly placed to capture the rumblings of Bárðarbunga. “They were in just the right place,” said White. (The researchers also rushed to place 10 additional seismometers.)

    Bárðarbunga would go on to belch 1.6 cubic kilometers of molten rock, dwarfing the 2010 eruption of Eyjafjallajökull. The first eruption occurred for a few hours on 29 August, and the next one came on 31 August, this time lasting 6 months.

    Earthquakes and volcanic eruptions often go hand in hand: The movement of molten rock underground—a magmatic intrusion—triggers ground shaking as it deforms the surrounding rock.

    The Bárðarbunga magmatic intrusion cut a 48-kilometer-long path through Earth’s crust over the course of 2 weeks. And earthquakes were plentiful: White and his colleagues recorded over 30,000 ranging in magnitude from 0.5 to 3.5.

    Precise Triangulation

    White and his colleagues pinpointed the locations of the earthquakes in three-dimensional space by triangulation. By very precisely measuring—to within 0.001 second—how long it took the earthquake waves to travel to different seismometers, the researchers estimated locations with uncertainties of only about 100 meters. That’s about 10 times better than most other studies, said Jenny Woods, a volcano seismologist at the University of Cambridge and member of the research team.

    Using the locations of the recorded earthquakes, the researchers inferred that Bárðarbunga’s magma moved in fits and starts—sometimes it stalled, and sometimes it moved forward at nearly 5 kilometers per hour (roughly human walking speed).

    These kinds of measurements make it possible to track the path of magma underground, said Woods. “Monitoring microseismicity is one of the most important tools we have for tracking intrusions of magma in real time.”

    Their results were published earlier this year in Earth and Planetary Science Letters.

    This study highlights the importance of having a dense monitoring network, said Luigi Passarelli, a volcanologist at King Abdullah University of Science and Technology in Saudi Arabia not involved in the research. “[It] can lead to better understanding of physical processes and eventually to improved real-time risk mitigation.”

    White and his colleagues will be returning to Iceland this July to download data from the 27 seismometers still deployed around Bárðarbunga. Collecting these measurements is crucial because the volcano appears to be refilling with magma underground, said White. “It’s still active.”

    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 2:35 pm on April 23, 2019 Permalink | Reply
    Tags: "National Volcano Warning System Gains Steam", , Eruptions have the potential to pose significant security and economic threats across the nation., It took more than a decade but a bill that funds U.S. volcano monitoring efforts and establishes a single system became law on 12 March., Kīlauea Volcano in Hawaii, Mount St. Helens in Washington State, Passage of Public Law No. 116-9 authorizing funding for the implementation of the NVEWS was introduced by Sen. Lisa Murkowski (R-Alaska), Since 1980 there have been 120 eruptions and 52 episodes of notable volcanic unrest at 44 U.S. volcanoes, Volcano Observatories: Alaska Volcano Observatory; California Volcano Observatory; Cascades Volcano Observatory; Yellowstone Volcano Observatory; Hawaiian Volcano Observatory, Vulcanology   

    From Eos: “National Volcano Warning System Gains Steam” 

    From AGU
    Eos news bloc

    From Eos

    4.23.19
    Forrest Lewis

    It took more than a decade, but a bill that funds U.S. volcano monitoring efforts and establishes a single system became law on 12 March.

    1
    The string of 2018 eruptions at Kīlauea Volcano in Hawaii resulted in about $800 million in damages but no loss of life. Credit: USGS

    Early in the morning on 17 May 2018, Hawaii’s Kīlauea Volcano unleashed a torrent of ash more than 3,000 meters into the sky. The explosion was just one noteworthy event in a months-long series of eruptions that destroyed more than 700 homes and caused $800 million in damage. Remarkably—thanks in large part to the relentless monitoring efforts of scientists at the Hawaiian Volcano Observatory (HVO)—no one died as a result of the destructive eruption sequence, which lasted into August.

    Across the country, in Washington, D.C., Senate lawmakers happened to meet that same day to vote on a topical piece of legislation: Senate bill 346 (S.346), the National Volcano Early Warning and Monitoring System Act. The Senate passed the bill by unanimous consent, marking a big step forward for a piece of legislation more than a decade in the making.

    2
    The 1980 eruption of Mount St. Helens in Washington was the most destructive volcanic eruption in U.S. history, responsible for the deaths of 57 people and $1.1 billion in damage. Credit: Austin S. Post, USGS.

    The bill sought to strengthen existing volcano monitoring systems and unify them into a single system, called the National Volcano Early Warning System (NVEWS), to ensure that volcanoes nationwide are adequately monitored in a standardized way.

    After ultimately lacking the floor time in the House necessary for a vote before the end of 2018, the bill was reintroduced as part of a larger package of natural resources–related bills at the start of the new Congress, which convened in January. The John D. Dingell, Jr. Conservation, Management, and Recreation Act (S.47) contained elements of more than 100 previously introduced bills related to public lands, natural resources, and water. This bill quickly breezed through Congress and was signed into law by President Donald J. Trump on 12 March; it’s now Public Law No. 116-9.

    Although the bipartisan effort and the bill’s other contents, including an urgent reauthorization of the recently expired Land and Water Conservation Fund, captured the media’s attention, Section 5001, National Volcano Early Warning and Monitoring System, will have lasting effects on the nation’s volcano hazard awareness and preparation.

    Volcano Observatories

    Only five U.S. volcano observatories monitor the majority of U.S. volcanoes, with support from the U.S. Geological Survey’s (USGS) Volcano Hazards Program and independent universities and institutions. These observatories are the Alaska Volcano Observatory in Fairbanks; the California Volcano Observatory in Menlo Park; the Cascades Volcano Observatory in Vancouver, Wash.; HVO; and the Yellowstone Volcano Observatory in Yellowstone National Park, Wyo.

    Volcanologists at these observatories monitor localized earthquakes, ground movement, gas emissions, rock and water chemistry, and remote satellite data to predict when and where volcanic eruptions will happen, ideally providing enough time to alert the local populace to prepare accordingly.

    The USGS has identified 161 geologically active volcanoes in 12 U.S. states as well as in American Samoa and the Northern Mariana Islands. More than one third of these active volcanoes are classified by the USGS as having either “very high” or “high” threat on the basis of their hazard potential and proximity to nearby people and property.

    Many of these volcanoes have monitoring systems that are insufficient to provide reliable warnings of potential eruptive activity, whereas at others, the monitoring equipment is obsolete. A 2005 USGS assessment identified 58 volcanoes nationwide as being undermonitored.

    “Unlike many other natural disasters…volcanic eruptions can be predicted well in advance of their occurrence if adequate in-ground instrumentation is in place that allows earliest detection of unrest, providing the time needed to mitigate the worst of their effects,” said David Applegate, USGS associate director for natural hazards, in a statement before a House subcommittee hearing in November 2017.

    During the 2018 Kīlauea eruption, HVO, the oldest of the five observatories, closely monitored the volcano and issued routine safety warnings. However, many volcanoes lack the monitoring equipment or attention given to Kīlauea. Of the 18 volcanoes identified in the USGS report as “very high threat,” Kīlauea is one of only three classified as well monitored (the other two are Mount St. Helens in Washington and Long Valley Caldera in California).

    Public Law No. 116-9 aims to change that. In addition to creating the NVEWS, the law authorizes the creation of a national volcano watch office that will operate 24 hours a day, 7 days a week. The legislation also establishes an external grant system within NVEWS to support research in volcano monitoring science and technology.

    4
    More than three of every four U.S. volcanoes that have erupted in the past 200 years are in Alaska (including Mount Redoubt, above). Credit: R. Clucas, USGS

    Volcanic Impacts

    Since 1980, there have been 120 eruptions and 52 episodes of notable volcanic unrest at 44 U.S. volcanoes, according to the USGS Volcano Hazards Program. The cataclysmic eruption of Mount St. Helens in 1980 was the most destructive, killing 57 people and causing $1.1 billion in damage.

    Although active volcanoes are concentrated in just a handful of U.S. states and territories, eruptions have the potential to pose significant security and economic threats across the nation. A 2017 report by the National Academies of Sciences, Engineering, and Medicine concluded that eruptions “can have devastating economic and social consequences, even at great distances from the volcano.”

    In 1989, for example, an eruption at Mount Redoubt in Alaska nearly caused a catastrophe. A plane en route from Amsterdam to Tokyo flew through a thick cloud of volcanic ash, causing all four engines to fail and forcing an emergency landing at Anchorage International Airport. More than 80,000 aircraft per year, carrying 30,000 passengers per day, fly over and downwind of Aleutian volcanoes on flights across the Pacific. The potential disruption to flight traffic as well as air quality issues from distant volcanoes poses serious health and economic risks for people across the United States.

    “People think they only have to deal with the hazards in their backyard, but volcanoes will come to you,” says Steve McNutt, a professor of volcano seismology at the University of South Florida in Tampa.

    National Volcano Early Warning and Monitoring System Act

    Passage of Public Law No. 116-9 authorizes funding for the implementation of the NVEWS. The bill recommends that Congress, during the annual appropriations process, appropriate $55 million over fiscal years 2019 through 2023 to the USGS to carry out the volcano monitoring duties prescribed in the bill.

    The bill was introduced by Sen. Lisa Murkowski (R-Alaska), first elected in 2002 and consistently the most steadfast champion of NVEWS legislation. Her home state of Alaska contains the most geologically active volcanoes in the country, and more than three of every four U.S. volcanoes that have erupted in the past 200 years are in Alaska. Often in concert with Alaska’s sole House representative, Don Young (R), Murkowski has introduced volcano monitoring legislation in nearly every congressional session since her election. Five bills over the past decade have stalled in committee without reaching the floor for a vote.

    “Our hazards legislation has become a higher priority because we realize that monitoring systems and networks are crucial to ensuring that Americans are informed of the hazards that we face,” Murkowski said in a speech at AGU’s Fall Meeting 2018 in Washington, D.C., last December. “They help us prepare and are crucial to protecting lives and property.”

    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 1:14 pm on April 17, 2019 Permalink | Reply
    Tags: "What Is the Most Dangerous Volcanic Hazard?", 1 Pyroclastic Flows (also known as hot ash flows or pyroclastic density currents), 2. Ash Fall, 3. Lahars (also known as volcanic mudflows), 4. Tsunamis, 5. Lava Flows, , , Vulcanology   

    From Discover Magazine: “What Is the Most Dangerous Volcanic Hazard?” 

    DiscoverMag

    From Discover Magazine

    April 17, 2019
    Erik Klemetti

    1
    The 2015 eruption of Calbuco in Chile, with the city of Puerto Montt in the foreground. Wikimedia Commons.

    Volcanoes can be pretty dangerous. Thankfully, we’ve gotten better over the last half century at getting people out of the way of volcanic hazards. However, many hundreds of millions of people still live close enough to volcanoes to feel the impact of an eruption — especially when the volcano decides to have a spectacular eruption.

    There are a lot of misconceptions out there about what the most dangerous aspects of a volcanic eruption might be. I think many people picture lava flows cascading down the sides of a volcano and imagine that the searing rivers of molten rock are what will do you in.

    Well, they’re right in one respect: stay in the path of a lava flow and you will likely cease being alive. But luckily, lava flows are actually pretty easy to avoid as they move rather slowly, rarely up to ~30 km/hr (20 mph) but more likely less than 8 km/hr (5 mph). You can probably out-walk most lava flows.

    So, what is it that makes volcanoes so deadly if it isn’t the copious volumes of lava they can produce? Here’s a little countdown of what I think are the most dangerous volcanic hazards based on the number of deaths associated with them, the potential for damage to houses and infrastructure, the frequency with which they occur and the difficulty of avoiding them.

    5. Lava Flows: After all that pre-amble about lava flows, here they are! Though lava flows may not cause many fatalities, the potential damage to infrastructure and homes is very high. Lava flows are also very common at certain types of volcanoes, so with that combination of frequency and destructiveness, we need to take lava flows seriously. The 2018 eruption at Kīlauea is a perfect example, where there were no fatalities but over 700 homes destroyed. However, the lava can be deadly in rare cases. This can happen when the composition and temperature of the lava means it is especially runny, so it travels fast. An eruption of Nyiragongo in the Democratic Republic of the Congo produced lava flows that moved through the city of Goma killing dozens.

    2
    Lava flow from the 2018 eruption of Kīlauea in Hawaii. USGS/HVO.

    4. Tsunamis: Tsunamis can be generated by geologic events other than eruptions — in fact, they are more common with earthquakes. However, volcanoes can produce these deadly ocean waves when part of the volcano collapses during an eruption. Most recently, the 2018 eruption of Anak Krakatau killed over 420 people when most of the relatively-small cinder cone collapsed during an eruption. The predecessor to Anak Krakatau — Krakatau itself — generated a massive 30-m tsunami when it collapsed into a caldera in 1883. That eruption and tsunami killed over 35,000 people along the Sunda Strait in Indonesia. Other volcanoes, like Unzen in Japan, have had deadly tsunamis as well.

    3
    Anak Krakatau not long after the 2018 collapse that generated a deadly tsunami. Alex Gerst – ISS/ESA.

    3. Lahars (also known as volcanic mudflows): You might be tempted to think mudflows couldn’t be too deadly, but these rivers of volcanic (and other) debris generated by snow and ice melt during an eruption or heavy precipitation on a volcano are very hazardous. Lahars have the consistency of wet cement and they flow at tens of kilometers per hour down river valleys. Many times, that allows for enough forewarning to escape if you are downriver, but the 1985 eruption of Nevado del Ruiz in Colombia proved that a lack of preparation can lead to over 20,000 deaths. Due to their density, lahars can destroy infrastructure and homes and bury towns (and people) rapidly. They can happen without an eruption, such as when old volcanic debris gets mobilized during heavy rain or snow melt. That’s why volcanoes like Mt. Rainier have lahar warning systems for the towns downslope from the volcano.

    4
    The town of Chaitén buried by lahar deposits from the 2008 eruption of Chaitén in Chile. Flickr.

    2. Ash Fall: It might look like snow, but volcanic ash is nasty. It’s made of tiny pieces of volcanic glass and other debris, so if you can imagine inhaling broken glass, well, you get the idea. It can be carried for potentially thousands of kilometers depending on the size of the eruption and winds. When it piles up, the ash can destroy roofs, contaminate water, annihilate vegetation and even block out the sun. If you are unlucky enough to breathe in the ash, it will coat the inside of your lungs and cut them up, people can die from the silica cement in their lungs and/or from more or less drowning in those fluids. Volcanic ash in the atmosphere can disable jet engines, so flying through even dilute ash clouds is a bad idea. Ash fall can be persistent as well, with a volcano producing ash that might accumulate a few millimeters or centimeters thick for months to years — and as I mentioned with lahars, you can get the ash moving again with heavy rains or even with winds.

    5
    Buildings destroyed by ash fall at Clark Air Base in the Philippines during the 1991 eruption of Pinatubo. USGS.

    1 Pyroclastic Flows (also known as hot ash flows or pyroclastic density currents): If you’re looking for that one-two punch of destruction and potential for major fatalities, it is hard to beat a pyroclastic flow. Imagine a cloud of hot volcanic gases and debris that ranges in size from tiny specks of ash to massive boulders, all moving down a volcano at over 300 km/hr (190 mph) at a temperature over 600ºC. You, your city, everything is toast. Some of the deadliest pyroclastic flows buried Pompeii in 79 A.D., wiped St. Pierre off the map during the 1902 eruption of Pelée, erased towns surrounding El Chichón in Mexico in 1982, snapped enormous trees as they flattened forest at Mount St. Helens in 1980 and buried entire valleys during the 1912 eruption of Novarupta in Alaska and 1991 eruption of Pinatubo. They are landscape-altering events that occur in mere moments. If you don’t get buried in the hot debris, you’ll be sizzled to death in the volcanic gases or choke on the ash.

    6
    Pyroclastic flow from Mount St. Helens in June 1980. USGS.

    Pyroclastic flows are generated a number of ways: a collapsing ash column from an eruption, a collapsing lava dome at the top of a volcano or an explosive eruption that moves sideways. Some recent research on pyroclastic flows suggests that they move so far and fast because they travel on a bed of air like a hovercraft. This allows them to travel tens of kilometers from the volcano and “leap” over obstacles. Even seasoned volcanologists can be caught off guard by unpredictable travel of pyroclastic flows. A 1991 eruption of Unzen killed Maurice and Katja Krafft, famed volcano documentarians, along with USGS volcanologist Harry Glicken. Pyroclastic flows need to be taken seriously because you will not survive being in the path of these clouds of volcanic fury.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 3:55 pm on April 8, 2019 Permalink | Reply
    Tags: "Volcanoes’ Deadly Pyroclastic Flows Surf on Air to Achieve Super Speed", , , Vulcanology   

    From PBS NOVA: “Volcanoes’ Deadly Pyroclastic Flows Surf on Air to Achieve Super Speed” 

    From PBS NOVA

    April 8, 2019
    Katherine J. Wu

    After an eruption, DIY cushions of gas help searing torrents of gas, ash, and rock spread miles from their source within a matter of minutes.

    1
    Pyroclastic flows contain a deadly combination of hot rock fragments and gas. Temperatures regularly top 1,000 degrees Fahrenheit, and these torrents can careen down mountainsides at hundreds of miles per hour—a baffling speed for a jumble of bulky debris. Image Credit: Andersen_Oystein, iStock

    Lava might be the most iconic fixture of an erupting volcano, but its sluggish ooze pales in comparison to the blast of a pyroclastic flow—a roiling river of gas, ash, and rock that can hurtle down a mountainside at hundreds of miles per hour. These fast-moving floods, with searing temperatures up to 1,800 degrees Fahrenheit, have been known to engulf villages miles from their source, leveling buildings and lifeforms alike.

    With their astonishing speed and reach, pyroclastic flows are often the most dangerous parts of volcanic explosions. They’re what consumed the city of Pompeii after Vesuvius exploded in 79 CE and, more recently, claimed the lives of at least 150 people when Guatemala’s Volcán de Fuego—literally, “Volcano of Fire”—blew its top last summer.

    4
    October 1974 eruption of Volcán de Fuego — seen from Antigua Guatemala, Guatemala. Pyroclastic flows can be seen descending the east (left-hand) flank. Paul Newton, Smithsonian Institution

    The very traits that make pyroclastic flows so deadly are also what make them mysterious. “With just a bunch of rocks going down a hill, you wouldn’t think of them going that fast,” says Janine Krippner, a volcanologist studying pyroclastic flows at the Smithsonian’s Global Volcanism Program who was not involved in the study. But a pyroclastic flow can transport thousands to millions of tons of volcanic material to regions dozens of miles from its source, bypassing barriers and surging up hilly terrain.

    Volcanologists have long been baffled by the way these torrents of gravelly debris seem to defy friction. But in a study published today in the journal Nature Geoscience, a team of scientists has finally pulled back the curtain on these catastrophic currents: By manufacturing their own cushions of air, pyroclastic flows buoy themselves off the roughness of rocky slopes, allowing them to glide down mountainsides unencumbered.

    “It’s basically like a hovercraft, where air is being blown down to support the weight of something heavy,” says study author Gert Lube [I assume no pun is intended], a volcanologist at Massey University in New Zealand. Of course, with pyroclastic flows, there’s no machinery doing the work. The entire process is DIY, spurring a self-sustaining cycle that ferries scorching devastation for miles on end.

    “This is outstanding work that provides…critical information about how pyroclastic flows work,” says Patricia Gregg, a volcano geophysicist at the University of Illinois at Urbana-Champaign who was not involved in the study. A deeper understanding of these dynamics, she says, could help forecast the hazard zones of these devastating flows—and aid officials in safely evacuating those most at risk.

    After all, pyroclastic flows are the most prolific killers from volcanic eruptions, accounting for about 60,000 deaths in the last 500 years. Unfortunately, they’re extremely difficult to study in their natural context. Not only is there danger posed by their inescapable speed—but even up close, these currents are so dense that it’s just about impossible to see how they interact with the surfaces they traverse.

    So rather than trying to get intimate with a bona fide pyroclastic flow, a team led by Lube decided to create their own. Together, they converted an abandoned boiler house into something of a makeshift log flume with a sloped, clear-sided 40-foot channel that spilled its contents outside the building. Just like on Splash Mountain, cameras were installed to capture the magic of the epic plunge.

    Into the chute went nearly 3,000 pounds of piping hot volcanic material. Within milliseconds, the mixture began to move. The researchers barely had time to blink before a coarse torrent of rock, shrouded in a billowing cloud of ash, cascaded out the other end of the slide. Then, as the current exited the boiler house, it hit flat ground and gradually began to slow—but not before it blanketed about 100 feet of ground with a jumble of grit.

    2
    A synthetic pyroclastic flow at the researchers’ eruption simulator in New Zealand. Over a ton of volcanic material from the 232 CE eruption of the Taupo Volcano in New Zealand was dumped down a flume that opened out into a lot. Image Credit: Gert Lube, Massey University.

    There was no volcano, and certainly no eruption. All the same, it was there: the inexplicable speed, the telltale gush of debris—a pyroclastic flow. But this time, it came with an explanation. With high-speed video footage on their side, the researchers could finally see directly into the belly of the beast.

    “These observations are super precious,” says Arianna Soldati, a volcanologist at Ludwig Maximilian University of Munich who was not involved in the study. “There aren’t many places like this in the world that have this kind of large-scale capability to [model] pyroclastic flows.”

    When Lube and his colleagues sifted through the recordings, they noticed a thin, air-rich layer, less than a millimeter thick, quickly developing between the flow and its chute. As the tangle of mixed material moved down the slope, it had naturally separated into layers, with the fastest moving ones on top. Gas, seeking the best route out of the high-pressure space created by jostling volcanic material, was drifting upwards into the atmosphere—but also downwards, below the current of rock itself.

    It was as if the gas had found a hidden trapdoor into the basement of the flow, where it generated a gentle buffer of air. Boosted atop this plush pocket of gas, the tide of debris sailed easily down its chute, freed of the constraints of friction.

    But eventually, as gas continued to escape the jumble, the mixture’s mojo petered out, finally grinding to a halt when the lubricant ran dry.

    “This really sheds light on the physics of the [bottom] region of these flows,” Soldati says. “Before, we did not fully understand what happens in the very thin contact area between the ground and the pyroclastic flow, but now we have a much better idea of what’s going on.”

    3
    The runout from a simulated pyroclastic flow. Once ejected from the flume, the ash cloud continued to spread for about 100 feet, while the rocky underflow ran out up to 85 feet. Image Credit: Gert Lube, Massey University

    Of course, differences remain between pyroclastic flows in the lab and in nature, Krippner says. “With all models, no matter how big we make them, it’s always a challenge to scale it up to an actual flow,” she says. What’s more, a range of pyroclastic flows exists: Some are more gassy, others chock full of rock. Due to these differences in composition, there won’t be a one-size-fits-all when it comes to predicting their behavior. All the same, Krippner says, “this is one more step forward in understanding how pyroclastic flows move.”

    Armed with this knowledge, researchers might be better equipped to predict the spread of these flows, upping the chances that civilians can make it to safety before disaster strikes. “Before, we might have put put people in harm’s way inadvertently because we didn’t understand the flow could go further,” Gregg says.

    Lube thinks that the same dynamics might also apply to other natural disasters, including snow avalanches and fast-moving landslides. Those theories need testing, but in the meantime, “we have a hand on this process now, and the data to describe it,” he says. “We can use this for hazard models to save people—that’s really possible now. And that means there is light at the end of the tunnel.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NOVA is the highest rated science series on television and the most watched documentary series on public television. It is also one of television’s most acclaimed series, having won every major television award, most of them many times over.

     
  • richardmitnick 9:19 am on March 29, 2019 Permalink | Reply
    Tags: , , , Vulcanology   

    From Cornell Chronicle: “Merged satellite, ground data may forecast volcanic eruptions” 

    From Cornell Chronicle

    1
    Kevin Reath, a Cornell University postdoctorate associate and USGS Powell Center Fellow, studied 17 years of satellite data on volcanic activity in Latin America to propose a way to predict deadly eruptions before they occur. John Munson/Cornell University

    March 28, 2019
    Blaine Friedlander
    bpf2@cornell.edu

    On Nov. 13, 1985, the Nevado del Ruiz volcano in the Andes – about 80 miles west of Bogota, Colombia – erupted, sending a pyroclastic flow down its mountainside.

    The heat melted the snow at an elevation of more than 17,000 feet, and volcanic ash muddied the resulting water – called lahar – that rushed into the nearby town of Amero. More than 23,000 people died.

    1
    Guatemala’s cone-shaped, very active Fuego volcano spews an ash column. It last erupted in June 2018. Kevin Reath/Cornell University

    “This volcano killed over 70 percent of the town’s population. They were unprepared for the eruption,” said Kevin Reath, a Cornell postdoctoral researcher.

    Reath’s work aims to prevent that from happening again. He has merged 17 years of satellite data on volcanoes with ground-based detail to form a model for state-of-the-art volcanic eruption prediction.

    Reath’s paper, “Thermal, Deformation, and Degassing Remote Sensing Time Series (CE 2000–2017) at the 47 Most-Active Volcanoes in Latin America: Implications for Volcanic Systems,” was published in the Journal of Geophysical Research: Solid Earth (American Geophysical Union) in February.

    “Volcanoes are hazardous to local and global populations, but only a fraction of volcanoes are continuously monitored by ground‐based sensors,” Reath said.

    In South America, volcanoes lace the Ring of Fire around the Pacific Ocean. More than 60 percent of Holocene-era volcanoes in Latin America are unmonitored by ground-based sensors, and those with ground sensors still have gaps that satellites can fill, Reath said.

    “We are compiling remote sensing data that has been underutilized,” he said.

    The model aggregates three types of critical information: thermal data, such as volcanic hot spots and how they change over time; degassing data, which examines the presence of sulfur dioxide; and deformation data, accounting for inflation and deflation of magma reservoirs – pockets of lava inside the Earth.

    “These data types have never really been intercompared in such an extensive database,” said Reath, who hopes to extract a more-robust understanding of volcanic processes.

    But his work is not all volcanic eruptions. With over 17 years of satellite data, the scientists can find value in observing quiet among the volcanoes. “When we can see the volcano calm and then see the volcano when it is erupting, we can observe what’s happening leading to eruption. We can get a comprehensive picture of a volcanic behavior,” he said.

    “Volcanoes have personalities,” Reath said. “Sometimes they have multiple personalities. Volcanoes can behave differently from each other, and volcanic behavior – from the same volcano – can vary from eruption to eruption. It helps geologists to understand what to look for before an eruption. We’re looking for typical volcanic background behavior and pre-eruptive behavior.”

    Joining Reath on the paper are: Matthew Pritchard, Cornell professor, earth and atmospheric sciences; Francisco Delgado, Ph.D. ’18; Samantha Moruzzi ’20 and Allison Alcott ’18; and Scott Henderson, Ph.D. ’15, former Cornell postdoctoral researcher. This work was supported by NASA; the European Space Agency; and the Volcano Remote Sensing Working Group, John Wesley Powell Center for Analysis and Synthesis, U.S. Geological Survey.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Once called “the first American university” by educational historian Frederick Rudolph, Cornell University represents a distinctive mix of eminent scholarship and democratic ideals. Adding practical subjects to the classics and admitting qualified students regardless of nationality, race, social circumstance, gender, or religion was quite a departure when Cornell was founded in 1865.

    Today’s Cornell reflects this heritage of egalitarian excellence. It is home to the nation’s first colleges devoted to hotel administration, industrial and labor relations, and veterinary medicine. Both a private university and the land-grant institution of New York State, Cornell University is the most educationally diverse member of the Ivy League.

    On the Ithaca campus alone nearly 20,000 students representing every state and 120 countries choose from among 4,000 courses in 11 undergraduate, graduate, and professional schools. Many undergraduates participate in a wide range of interdisciplinary programs, play meaningful roles in original research, and study in Cornell programs in Washington, New York City, and the world over.

     
  • richardmitnick 3:50 pm on March 25, 2019 Permalink | Reply
    Tags: , , , , Vulcanology, WOVO-World Organization of Volcano Observatories   

    From Eos: “Data from Past Eruptions Could Reduce Future Volcano Hazards” 

    From AGU
    Eos news bloc

    From Eos

    3.25.19
    Fidel Costa
    Christina Widiwijayanti
    Hanik Humaida

    Optimizing the Use of Volcano Monitoring Database to Anticipate Unrest; Yogyakarta, Indonesia, 26–29 November 2018.

    1
    Java’s Mount Merapi volcano (right), overlooking the city of Yogyakarta, is currently slowly extruding a dome. Mount Merbabu volcano (left) has not erupted for several centuries. Participants at a workshop last November discussed the development and use of a volcano monitoring database to assist in mitigating volcano hazards. Credit: Fidel Costa

    In 2010, Mount Merapi volcano on the Indonesian island of Java erupted explosively—the largest such eruption in 100 years.

    1
    Mount Merapi, viewed from Umbulharjo
    16 April 2014
    Crisco 1492

    Merapi sits only about 30 kilometers from the city of Yogyakarta, home to more than 1 million people. The 2010 eruption forced more than 390,000 people to evacuate the area, and it caused 386 fatalities. In the past few months, the volcano has started rumbling again, and it is currently extruding a dome that is slowly growing.

    Will Merapi’s rumblings continue like this, or will they turn into another large, explosive eruption? Answering this question largely depends on having real-time monitoring data covering multiple parameters, including seismicity, deformation, and gas emissions. But volcanoes can show a wide range of behaviors. A volcanologist’s diagnosis of what the volcano is going to do next relies largely on comparisons to previous cases and thus on the existence of an organized and searchable database of volcanic unrest.

    For over a decade, the World Organization of Volcano Observatories (WOVO) has contributed to the WOVOdat project, which has collected monitoring data from volcanoes worldwide. WOVOdat has grown into an open-source database that should prove very valuable during a volcanic crisis. However, there are many challenges ahead to reaching this goal:

    How do we standardize and capture spatiotemporal data produced in a large variety of formats and instruments?
    How do we go from multivariate (geochemical, geophysical, and geodetic) signals to statistically meaningful indicators for eruption forecasts?
    How do we properly compare periods of unrest between volcanic eruptions?

    Participants at an international workshop last November discussed these and other questions. The workshop was organized by the Earth Observatory of Singapore and the Center for Volcanology and Geological Hazard Mitigation in Yogyakarta. An interdisciplinary group of over 40 participants, including students and experts from more than 10 volcano observatories in Indonesia, the Philippines, Papua New Guinea, Japan, France, Italy, the Caribbean, the United States, Chile, and Singapore, gathered to share their expertise on handling volcano monitoring data, strategize on how to improve on monitoring data management, and analyze past unrest data to better anticipate future unrest and eruptions.

    Participants agreed on the need for a centralized database that hosts multiparameter monitoring data sets and that allows efficient data analysis and comparison between a wide range of volcanoes and eruption styles. They proposed the following actions to optimize the development and use of a monitoring database:

    develop automatic procedures for data processing, standardization, and rapid integration into a centralized database platform
    develop tools for diagnosis of unrest patterns using statistical analytics and current advancement of machine learning techniques
    explore different variables, including eruption styles, morphological features, eruption chronology, and unrest indicators, to define “analogue volcanoes” (classes of volcanoes that behave similarly) and “analogue unrest” for comparative studies
    develop protocols to construct a short-term Bayesian event tree analysis based on real-time data and historical unrest

    Volcano databases such as WOVOdat aim to be a reference for volcanic crisis and hazard mitigation and to serve the community in much the same way that an epidemiological database serves for medicine. But the success of such endeavors requires the willingness of observatories, governments, and researchers to agree on data standardization; efficient data reduction algorithms; and, most important, data sharing to enable findable, accessible, interoperable, and reusable (FAIR) data across the volcano community.

    —Fidel Costa (fcosta@ntu.edu.sg), Earth Observatory of Singapore and Asian School of the Environment, Nanyang Technological University, Singapore; Christina Widiwijayanti, Earth Observatory of Singapore, Nanyang Technological University, Singapore; and Hanik Humaida, Center for Volcanology and Geological Hazard Mitigation, Geological Agency of Indonesia, Bandung

    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 3:21 pm on March 19, 2019 Permalink | Reply
    Tags: , Bezymianny volcano, , , Sheveluch volcano, The Kamchatka Peninsula in far eastern Russia is one of the most active volcanic areas on Earth., Vulcanology   

    From Discover Magazine: “Two Russian Volcanoes Erupting in Tandem” 

    DiscoverMag

    From Discover Magazine

    March 19, 2019
    Erik Klemetti

    1
    The long ash plume from Bezymianny seen stretching across the Pacific Ocean on March 17, 2019 by Terra’s MODIS imager. The smaller plume from Sheveluch can be seen just above the darker Bezymianny plume. NASA.

    NASA Terra MODIS schematic

    NASA Terra satellite

    The Kamchatka Peninsula in far eastern Russia is one of the most active volcanic areas on Earth. It isn’t surprising to find multiple volcanoes erupting each week and this week is no exception. Two side-by-side volcanoes — Bezymianny and Sheveluch — were simultaneously erupting over the weekend (above). The eruption at Bezymianny was big enough to cause some air travel over the peninsula to change their flight paths to avoid the ash, but that’s business-as-usual in Kamchatka.

    2
    Bezymianny volcano

    3
    Sheveluch volcano

    Kamchakta is remote and fairly sparsely populated. Only about 1600 people live within 30 kilometers of Sheveluch and only 47 within 30 kilometers of Bezymianny. The monitoring of the volcanoes in Kamchatka is done by KVERT (Kamchatka Volcanic Eruption Response Team) with help from the Alaska Volcano Observatory. The low hazard for people on the ground is balanced by higher hazard for people in aircraft that traverse the airspace over and near the peninsula.

    Most of this traffic is from the Americas and Europe to eastern Asia, so someone flying from Seattle to Hong Kong might be in the path of an erupting volcano even if their destinations are thousands of kilometers from the action. Ash is very bad for jet aircraft, so avoiding ash plumes is vital, which means the Volcanic Ash Advisory Centers have to use satellite data and ground observations to warn airlines and air traffic controllers about potential ash plumes.

    That makes Kamchatka a real problem. Not only are the volcanoes remote and challenging to monitor, but they also tend towards explosive eruptions. Case in point the eruption of Bezymianny on March 16. That blast sent ash to 15 kilometers (50,000 feet), well above where commercial air traffic flies. The ash drifted east over the Pacific Ocean and ended up causing flights in the Aleutians as far east as Unalaska (2000 kilometers away!) to be cancelled. Trans-Pacific flights had to follow some different routes as well to avoid the ash.

    Although Kamchatka doesn’t have a lot of people to watch the volcanoes erupt, KVERT does operate a bunch of webcams to watch the eruptions. Bezymianny has three pointed at the volcano as does Sheveluch. This means you can see some of their giant explosions while sitting across the globe. Even at night you can spot activity, like a glowing lava dome on Sheveluch (below). Both the eruption at Bezymianny and Shiveluch are caused by lava domes forming and then getting destroyed as the pressure building underneath the dome gets to high, causing the dome to “pop” like a cork (if the cork also shattered into tiny pieces). The sticky lava erupted at these volcanoes leads to these explosive eruptions.

    There aren’t many truly “remote” places on Earth these days, so volcanoes in areas where people are rare can still be a big hazard. 100 years ago, we might not have even known eruptions like these at Bezymianny and Sheveluch were even happening unless someone happened to be nearby or notice ash falling on their town. Thanks to all the satellites watching the planet, we now know a lot more about how volcanically active the Earth is.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 5:15 pm on February 28, 2019 Permalink | Reply
    Tags: A NASA-NOAA satellite confirmed Manaro Voui had the largest eruption of sulfur dioxide that year, , NASA Suomi NPP satellite, NOAA Visible Infrared Imaging Radiometer Suite (VIIRS), The Manaro Voui volcano on the island of Ambae in the nation of Vanuatu in the South Pacific Ocean made the 2018 record books., Vulcanology   

    From NASA Goddard Space Flight Center: “2018’s Biggest Volcanic Eruption of Sulfur Dioxide” 

    NASA Goddard Banner
    From NASA Goddard Space Flight Center

    Feb. 28, 2019

    Jenny Marder
    NASA’s Goddard Space Flight Center

    1
    The natural-color image above was acquired on July 27, 2018, by the Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP. Image by Lauren Dauphin, NASA Earth Observatory.

    NOAA Visible Infrared Imaging Radiometer Suite (VIIRS)

    NASA Suomi NPP satellite

    The Manaro Voui volcano on the island of Ambae in the nation of Vanuatu in the South Pacific Ocean made the 2018 record books.

    2
    Manaro Voui volcano on the island of Ambae in the nation of Vanuatu

    A NASA-NOAA satellite confirmed Manaro Voui had the largest eruption of sulfur dioxide that year.

    The volcano injected 400,000 tons of sulfur dioxide into the upper troposphere and stratosphere during its most active phase in July, and a total of 600,000 tons in 2018. That’s three times the amount released from all combined worldwide eruptions in 2017.

    3
    The map above shows stratospheric sulfur dioxide concentrations on July 28, 2018, as detected by OMPS on the Suomi-NPP satellite, when Ambae was at the peak of its sulfur emissions. For perspective, emissions from Hawaii’s Kilauea and the Sierra Negra volcano in the Galapagos are shown on the same day.
    Credits: Image by Lauren Dauphin, NASA Earth Observatory, using OMPS data from GES DISC and Simon Carn.

    During a series of eruptions at Ambae in 2018, volcanic ash also blackened the sky, buried crops and destroyed homes, and acid rain turned the rainwater, the island’s main source of drinking water, cloudy and “metallic, like sour lemon juice,” said New Zealand volcanologist Brad Scott. Over the course of the year, the island’s entire population of 11,000 was forced to evacuate.

    At the Ambae volcano’s peak eruption in July, measurements showed the results of a powerful burst of energy that pushed gas and ash to the upper part of the troposphere and into the stratosphere, at an altitude of 10.5 miles. Sulfur dioxide is short-lived in the atmosphere, but once it penetrates into the stratosphere, where it combines with water vapor to convert to sulfuric acid aerosols, it can last much longer — for weeks, months or even years, depending on the altitude and latitude of injection, said Simon Carn, professor of volcanology at Michigan Tech.

    In extreme cases, like the 1991 eruption of Mount Pinatubo in the Philippines, these tiny aerosol particles can scatter so much sunlight that they cool the Earth’s surface below.

    The map above shows stratospheric sulfur dioxide concentrations on July 28, 2018, as detected by OMPS on the Suomi-NPP satellite. Ambae (also known as Aoba) was near the peak of its sulfur emissions at the time. For perspective, emissions from

    Hawaii’s Kilauea and the Sierra Negra volcano in the Galapagos are shown on the same day. The plot below shows the July-August spike in emissions from Ambae.

    “With the Kilauea and Galapagos eruptions, you had continuous emissions of sulfur dioxide over time, but the Ambae eruption was more explosive,” said Simon Carn, professor of volcanology at Michigan Tech. “You can see a giant pulse in late July, and then it disperses.”

    4
    The plot shows the July-August spike in emissions from Ambae.
    Credits: Image by Lauren Dauphin, NASA Earth Observatory, using OMPS data from GES DISC and Simon Carn.

    The OMPS nadir mapper instruments on the Suomi-NPP and NOAA-20 satellites contain hyperspectral ultraviolet sensors, which map volcanic clouds and measure sulfur dioxide emissions by observing reflected sunlight. Sulfur dioxide (SO2) and other gases like ozone each have their own spectral absorption signature, their unique fingerprint. OMPS measures these signatures, which are then converted, using complicated algorithms, into the number of SO2 gas molecules in an atmospheric column.

    “Once we know the SO2 amount, we put it on a map and monitor where that cloud moves,” said Nickolay Krotkov, a research scientist at NASA Goddard’s Atmospheric Chemistry and Dynamics Laboratory.

    These maps, which are produced within three hours of the satellite’s overpass, are used at volcanic ash advisory centers to predict the movement of volcanic clouds and reroute aircraft, when needed.

    Mount Pinatubo’s violent eruption injected about 15 million tons of sulfur dioxide into the stratosphere. The resulting sulfuric acid aerosols remained in the stratosphere for about two years, and cooled the Earth’s surface by a range of 1 to 2 degrees Fahrenheit.

    This Ambae eruption was too small to cause any such cooling. “We think to have a measurable climate impact, the eruption needs to produce at least 5 to 10 million tons of SO2,” Carn said.

    Still, scientists are trying to understand the collective impact of volcanoes like Ambae and others on the climate. Stratospheric aerosols and other volcanic gases emitted by volcanoes like Ambae can alter the delicate balance of the chemical composition of the stratosphere. And while none of the smaller eruptions have had measurable climate effects on their own, they may collectively impact the climate by sustaining the stratospheric aerosol layer.

    “Without these eruptions, the stratospheric layer would be much, much smaller,” Krotkov said.

    See the full article here.


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.


    NASA/Goddard Campus

     
  • richardmitnick 10:34 am on February 22, 2019 Permalink | Reply
    Tags: "Did volcanic eruptions help kill off the dinosaurs?", A large impact crater in the Gulf of Mexico, A massive asteroid strike 66 million years ago that unleashed towering tsunamis and blotted out the sun with ash causing a plunge in global temperatures, Across what is India today countless volcanic seams opened in the ground releasing a flood of lava resembling last year’s eruptions in Hawaii—except across an area the size of Texas, , Over the course of 1 million years the greenhouse gases from these eruptions could have raised global temperatures and poisoned the oceans leaving life in a perilous state before the asteroid impact, , Some 400000 years before the impact the planet gradually warmed by some 5°C only to plunge in temperature right before the mass extinction, The Deccan Traps, Vulcanology   

    From Science Magazine: “Did volcanic eruptions help kill off the dinosaurs?” 

    AAAS
    From Science Magazine

    Feb. 21, 2019
    Paul Voosen

    1
    The hardened lava flows of the Deccan Traps, in western India, may have played a role in the demise of the dinosaurs. Gerta Keller

    What killed off the dinosaurs? The answer has seemed relatively simple since the discovery a few decades ago of a large impact crater in the Gulf of Mexico. It pointed to a massive asteroid strike 66 million years ago that unleashed towering tsunamis and blotted out the sun with ash, causing a plunge in global temperatures.

    But the asteroid wasn’t the only catastrophe to wallop the planet around this time. Across what is India today, countless volcanic seams opened in the ground, releasing a flood of lava resembling last year’s eruptions in Hawaii—except across an area the size of Texas. Over the course of 1 million years, the greenhouse gases from these eruptions could have raised global temperatures and poisoned the oceans, leaving life in a perilous state before the asteroid impact.

    The timing of these eruptions, called the Deccan Traps, has remained uncertain, however. And scientists such as Princeton University’s Gerta Keller have acrimoniously debated [Science] how much of a role they played in wiping out 60% of all the animal and plant species on Earth, including most of the dinosaurs.

    That debate won’t end today. But two studies published in Science have provided the most precise dates for the eruptions so far—and the best evidence yet that the Deccan Traps may have played some role in the dinosaurs’ demise.

    There’s long been evidence that Earth’s climate was changing before the asteroid hit. Some 400,000 years before the impact, the planet gradually warmed by some 5°C, only to plunge in temperature right before the mass extinction. Some thought the Deccan Traps could be responsible for this warming, suggesting 80% of the lava had erupted before the impact.

    But the new studies counter that old view. In one, Courtney Sprain, a geochronologist at the University of Liverpool in the United Kingdom, and colleagues took three trips to India’s Western Ghats, home of some of the thickest lava deposits from the Deccan Traps. They sampled various basaltic rocks formed by the cooled lava. The technique they used, called argon-argon dating, dates the basalt’s formation, giving a direct sense of the eruptions’ timing.

    The researchers’ dates suggest the eruptions began 400,000 years before the impact, and kicked into high gear afterward, releasing 75% of their total volume [Science]in the 600,000 years after the asteroid strike. If the Deccan Traps had kicked off global warming, their carbon dioxide (CO2) emissions had to come before the lava flows really got going—which, Sprain adds, is plausible, given how much CO2 scientists see leaking from modern volcanoes, even when they’re not erupting.

    The dates, and the increase in lava volume after the impact, also line up with a previous suggestion by Sprain’s team, including her former adviser, Paul Renne, a geochronologist at the University of California, Berkeley, that the two events are directly related: The impact might have struck the planet so hard that it sent the Deccan Traps into eruptive high gear [Science].

    The second study used a different method to date the eruptions. A team including Keller and led by Blair Schoene, a geochronologist at Princeton, looked at zircon crystals [Science] trapped between layers of basalt. These zircons can be precisely dated using the decay of uranium to lead, providing time stamps for the layers bracketing the eruptions. The zircons are also rare: It was a full-time job, lasting several years, to sift them out from the rocks at the 140 sites they sampled.

    The dates recovered from the crystals suggest that the Deccan Traps erupted in four intense pulses [Science] rather than continuously, as Sprain suggests. One pulse occurred right before the asteroid strike. That suggests the impact did not trigger the eruptions, he says. Instead, it’s possible this big volcanic pulse before the asteroid impact did play a role in the extinction, Schoene says. “It’s very tempting to say.” But, he adds, there’s never been a clear idea of how exactly these eruptions could directly cause such extinctions.

    Though the two studies differ, they largely agree on the overall timing of the Deccan eruptions, Schoene says. “If you plot the data sets over each other, there’s almost perfect agreement.”

    This match represents a victory, says Noah McLean, a geochemist at the University of Kansas in Lawrence, who was not involved in either study. For decades, dates produced with these geochronological techniques couldn’t line up. But improved techniques and calibration, McLean says, “helped us go from million-year uncertainties to tight chronologies.”

    Solving the mystery of how the dinosaurs died isn’t just an academic problem. Understanding how the eruptions’ injection of CO2 into the atmosphere changed the planet is vital not only for our curiosity about the dinosaurs’ end, but also as an analog for today, Sprain says. “This is the most recent mass extinction we have,” Sprain says. Teasing apart the roles of the impact and the Deccan Traps, she says, can potentially help us understand where we’re heading.

    See the full article here .


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: