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  • richardmitnick 10:14 am on July 28, 2020 Permalink | Reply
    Tags: "The explosive secret hidden beneath seemingly trustworthy volcanoes", , , , The team studied two Galápagos volcanoes., Trinity College Dublin, Vulcanology   

    From Trinity College Dublin: “The explosive secret hidden beneath seemingly trustworthy volcanoes” 

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    From Trinity College Dublin

    28th July 2020
    Thomas Deane, Media Relations Officer
    deaneth@tcd.ie
    +353 1 896 4685

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    The 2015 eruption at Wolf volcano in the Galapagos Archipelago, credit Gabriel Salazar, La Pinta Yacht Expedition.

    An international team of volcanologists working on remote islands in the Galápagos Archipelago has found that volcanoes which reliably produce small basaltic lava eruptions hide chemically diverse magmas in their underground plumbing systems – including some with the potential to generate explosive activity.

    Many volcanoes produce similar types of eruption over millions of years. For example, volcanoes in Iceland, Hawai’i and the Galápagos Islands consistently erupt lava flows – comprised of molten basaltic rock – which form long rivers of fire down their flanks.

    Although these lava flows are potentially damaging to houses close to the volcano, they generally move at a walking pace and do not pose the same risk to life as larger explosive eruptions, like those at Vesuvius or Mt. St. Helens. This long-term consistency in a volcano’s eruptive behaviour informs hazard planning by local authorities.

    The research team, led by Dr Michael Stock from Trinity and comprising scientists from the US, UK and Ecuador, studied two Galápagos volcanoes, which have only erupted compositionally uniform basaltic lava flows at the Earth’s surface for their entire lifetimes. By deciphering the compositions of microscopic crystals in the lavas, the team was able to reconstruct the chemical and physical characteristics of magmas stored underground beneath the volcanoes.

    The results of the study show that – in contrast with the monotonous basaltic lavas erupted at the Earth’s surface – magmas beneath the volcanoes are extremely diverse and include compositions similar to those erupted at Mt. St. Helens.

    The team believes that volcanoes consistently erupt compositionally uniform basaltic lavas when the amount of magma flushing through the ground beneath the edifice is high enough to “overprint” any chemical diversity. This can occur when volcanoes are located close to a “hot spot” – a plume of hot magma rising towards the surface from deep within the Earth.

    However, the chemically diverse magmas which the team discovered could become mobile and ascend towards the surface under certain circumstances. In this case, volcanoes that have reliably produced basaltic lava eruptions for millennia might undergo unexpected changes to more explosive activity in the future.

    Dr Stock, from Trinity’s School of Natural Sciences, and lead author on the paper just published by leading international journal, Nature Communications, said:

    “This was really unexpected. We started the study wanting to know why these volcanoes were so boring and what process caused the erupted lava compositions to remain constant over long timescales. Instead we found that they aren’t boring at all – they just hide these secret magmas under the ground.

    “Although there’s no sign that these Galápagos volcanoes will undergo a transition in eruption style any time soon, our results show why other volcanoes might have changed their eruptive behaviour in the past. The study will also help us to better understand the risks posed by volcanoes in other parts of the world – just because they’ve always erupted a particular way in the past doesn’t mean you can rely on them to continue doing the same thing indefinitely into the future.”

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    The team collects samples from solidified lava flows on Wolf volcano with assistance from a Galápagos National Park ranger, credit Dr Benjamin Bernard.

    Dr Benjamin Bernard, a volcanologist involved in monitoring Galápagos volcanoes at Instituto Geofísico and co-author on the paper, added:

    “This discovery is a game-changer because it allows us to reconcile apparently divergent observations, such as the presence of explosive deposits at several Galápagos volcanoes. It also allows us to better understand the behaviour of these volcanoes, which is essential for volcano monitoring and hazard assessment.”

    This work is funded by the Charles Darwin and Galápagos Islands Fund at Christ’s College, University of Cambridge, and the US National Science Foundation. It was conducted with support from the Ecuadorian Instituto Geofísico, Galápagos National Park and Charles Darwin Foundation.

    See the full article here.

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  • richardmitnick 1:21 pm on July 17, 2020 Permalink | Reply
    Tags: "Photos may improve understanding of volcanic processes", , , , , Vulcanology   

    From Pennsylvania State University: “Photos may improve understanding of volcanic processes” 

    Penn State Bloc

    From Pennsylvania State University

    July 16, 2020
    Patricia Craig

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    A team of Penn State researchers studied Telica Volcano, a persistently active volcano in western Nicaragua, to both observe and quantify small-scale intra-crater change associated with background and eruptive activity. Image: Google Earth

    The shape of volcanoes and their craters provide critical information on their formation and eruptive history. Techniques applied to photographs — photogrammetry — show promise and utility in correlating shape change to volcanic background and eruption activity.

    Changes in volcano shape — morphology — that occur with major eruptions are quantifiable, but background volcanic activity, manifesting as small volume explosions and crater wall collapse, can also cause changes in morphology and are not well quantified.

    A team of Penn State researchers studied Telica Volcano, a persistently active volcano in western Nicaragua, to both observe and quantify small-scale intra-crater change associated with background and eruptive activity. Geologists consider Telica ‘persistently’ active because of its high levels of seismicity and volcanic degassing, and it erupts on less than 10-year time periods.


    Telica volcano
    A team of Penn State researchers studied Telica Volcano, a persistently active volcano in western Nicaragua, to both observe and quantify small-scale intra-crater change associated with background and eruptive activity.

    The team used direct observations of the crater, photographic observations from 1994 to 2017 and photogrammetric techniques on photos collected between 2011 and 2017 to analyze changes at Telica in the context of summit crater formation and eruptive processes. They used structure-from-motion (SfM), a photogrammetric technique, to construct 3D models from 2D images. They also used point cloud differencing, a method used to measure change between photo sampling periods, to compare the 3D models, providing a quantitative measure of change in crater morphology. They reported their results in Geochemistry, Geophysics, Geosystems.

    “Photos of the crater were taken as part of a multi-disciplinary study to investigate Telica’s persistent activity,” said Cassie Hanagan, lead author on the study. “Images were collected from our collaborators to make observations of the crater’s features such as the location and number of fumaroles or regions of volcanic degassing in the crater. For time periods that had enough photos, SfM was used to create 3D models of the crater. We could then compare the 3D models between time periods to quantify change.”

    Using the SfM-derived 3D models and point cloud differencing allowed the team to quantify how the crater changed through time.

    “We could see the changes by visually looking at the photos, but by employing SfM, we could quantify how much change had occurred at Telica,” said Peter La Femina, associate professor of geosciences in Penn State’s Department of Geosciences. “This is one of the first studies to look at changes in crater morphology associated with background and eruptive activity over a relatively long time span, almost a 10-year time period.”

    Telica’s morphological changes were then compared to the timing of eruptive activity to investigate the processes leading to crater formation and eruption.

    Volcanoes erupt when pressure builds beyond a breaking point. At Telica, two mechanisms for triggering eruptions have been hypothesized. These are widespread mineralization within the underground hydrothermal system that seals the system and surficial blocking of the vent by landslides and rock fall from the crater walls. Both mechanisms could lead to increases in pressure and then eruption, according to the researchers.

    “One question was whether or not covering the vents on the crater floor could cause pressure build up, and if that would cause an explosive release of this pressure if the vent were sufficiently sealed,” said Hanagan.

    Comparing the point cloud differencing results and the photographic observations indicated that vent infill by mass wasting from the crater walls was not likely a primary mechanism for sealing of the volcanic system prior to eruption.

    “We found that material from the crater walls does fall on the crater floor, filling the eruptive vent,” said La Femina. “But at the same time, we still see active fumaroles, which are vents in the crater walls where high temperature gases and steam are emitted. The fumaroles remained active even though the talus from the crater walls covered the vents. This suggests that at least the deeper magma-hydrothermal system is not directly sealed by landslides.”

    The researchers further note that crater wall material collapse is spatially correlated to where degassing is concentrated, and that small eruptions blow out this fallen material from the crater floor. They suggest these changes sustain a crater shape similar to other summit craters that formed by collapse into an evacuated magma chamber.

    “What we found is that during the explosions, Telica is throwing out a lot of the material that came from the crater walls,” said La Femina. “In the absence of magmatic eruptions, the crater is forming through this background process of crater wall collapse, and the regions of fumarole activity collapse preferentially.”

    The team collaborated with Mel Rogers, assistant research professor at the University of South Florida. Hanagan, now a graduate student at the University of Arizona, completed this research as part of her Schreyer Honors College honors thesis and Department of Geosciences senior thesis.

    The National Science Foundation and NASA PA Space Grant WISER program fellowship partially funded this research.

    See the full article here .

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    Penn State Campus

    About Penn State

    WHAT WE DO BEST

    We teach students that the real measure of success is what you do to improve the lives of others, and they learn to be hard-working leaders with a global perspective. We conduct research to improve lives. We add millions to the economy through projects in our state and beyond. We help communities by sharing our faculty expertise and research.

    Penn State lives close by no matter where you are. Our campuses are located from one side of Pennsylvania to the other. Through Penn State World Campus, students can take courses and work toward degrees online from anywhere on the globe that has Internet service.

    We support students in many ways, including advising and counseling services for school and life; diversity and inclusion services; social media sites; safety services; and emergency assistance.

    Our network of more than a half-million alumni is accessible to students when they want advice and to learn about job networking and mentor opportunities as well as what to expect in the future. Through our alumni, Penn State lives all over the world.

    The best part of Penn State is our people. Our students, faculty, staff, alumni, and friends in communities near our campuses and across the globe are dedicated to education and fostering a diverse and inclusive environment.

     
  • richardmitnick 8:48 am on July 10, 2020 Permalink | Reply
    Tags: "How volcanoes explode deep under the ocean", , , , , Vulcanology   

    From EarthSky: “How volcanoes explode deep under the ocean” 

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    From EarthSky

    July 8, 2020
    Eleanor Imster

    Explosive volcanic eruptions are possible deep down in the sea – although the water masses exert enormous pressure there. An international team reports how this can happen.

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    An island of the Azores: It’s an example of an underwater volcano that has reached the sea surface. The crater is clearly visible. Image via aroxopt/ iStock.com/ University of Würzburg.

    Most of the volcanic eruptions on Earth happen unseen at the bottom of the world’s oceans. In recent years, oceanography has shown that these submarine volcanoes not only deposit lava, but also eject large amounts of volcanic ash.

    Bernd Zimanowski, of Julius-Maximilians-Universität in Bavaria, said in a statement:

    “So even under layers of water kilometers thick, which exert great pressure and thus prevent effective degassing, there must be mechanisms that lead to an ‘explosive’ disintegration of magma.”

    How are explosive volcanic eruptions possible deep underwater? Zimanowski is part of an international research group that has now demonstrated a mechanism for these undersea explosions. The results were published June 29, 2020, in the peer-reviewed journal Nature Geoscience.

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    There are around 1,900 active volcanoes on land or as islands. The number of submarine volcanoes is estimated to be much higher. Exact numbers are not known because the deep sea is largely unexplored. Accordingly, most submarine volcanic eruptions go unnoticed. Submarine volcanoes grow slowly upwards by recurring eruptions. When they reach the water surface, they become volcanic islands – like Stromboli near Sicily (an active volcano, pictured above) or some of the Canary Islands. Image via Novinite.com.

    The team did research at the Havre Seamount volcano , which lies northwest of New Zealand about half a mile (1,000 meters) below the sea surface. The scientific community became aware of the volcano when it erupted in 2012. The eruption created a floating carpet of pumice that expanded to about 150 square miles (400 square km), roughly the size of the city of Vienna.

    For the new research, the team used a diving robot to examine the ash deposits on the seabed. From the observational data the group detected more than 100 million cubic meters (3.5 billion cubic feet) of volcanic ash. The diving robot also took samples from the seafloor, which were then analyzed in the lab. Zimanowski said:

    “We melted the material and brought it into contact with water under various conditions. Under certain conditions, explosive reactions occurred which led to the formation of artificial volcanic ash.”

    The comparison of this ash with the natural samples showed that processes in the laboratory must have been similar to those that took place at a depth of 1,000 meters on the sea floor. Zimanowski added:

    “In the process, the molten material was placed under a layer of water in a crucible with a diameter of ten centimeters and then deformed with an intensity that can also be expected when magma emerges from the sea floor. Cracks are formed and water shoots abruptly into the vacuum created. The water then expands explosively. Finally, particles and water are ejected explosively. We lead them through an U-shaped tube into a water basin to simulate the cooling situation under water.”

    The particles created in this way, the “artificial volcanic ash”, corresponded in shape, size and composition to the natural ash.

    The researchers believe that further investigations should also show whether underwater volcanic explosions could possibly have an effect on the climate. Zimanowski said:

    “With submarine lava eruptions, it takes a quite long time for the heat of the lava to be transferred to the water. In explosive eruptions, however, the magma is broken up into tiny particles. This may create heat pulses so strong that the thermal equilibrium currents in the oceans are disrupted locally or even globally.”

    See the full article here .


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    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 2:21 pm on June 30, 2020 Permalink | Reply
    Tags: , , , , Vulcanology   

    From Imperial College London: “Study reveals how water in deep Earth triggers earthquakes and volcanic activity” 

    From Imperial College London

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    The Antilles volcanoes (The Quill on Statia)

    Scientists have for the first time linked the deep Earth’s water cycle to earthquakes and volcanic activity.

    Water, sulphur and carbon dioxide, which are cycled through the deep Earth, play a key role in the evolution of our planet – including in the formation of continents, the emergence of life, the concentration of mineral resources, and the distribution of volcanoes and earthquakes.

    Subduction zones, where tectonic plates meet and one plate sinks beneath another, are a key part of the cycle – with large volumes of water going into and coming out from the Earth, mainly through volcanic eruptions. Yet, just how (and how much) water is transported via subduction, and its effect on natural hazards and the formation of natural resources, has been poorly understood.

    Now, a new paper from a project led by researchers from Bristol, Durham, and Imperial has shown that water in the deep Earth triggers earthquakes and volcanic activity by releasing fluids along fault lines and lowering the melting point of rocks.

    The researchers say this is the first conclusive evidence that directly links the water-in and water-out parts of the cycle with magma (melted rock) production and earthquake activity.

    The paper is published in Nature.

    Plate pilgrimage

    As tectonic plates journey from where they are first made at mid-ocean ridges to subduction zones – where they meet other plates – seawater enters the rocks through cracks, faults and by binding to minerals. Upon reaching a subduction zone, the sinking plate heats up and gets squeezed, resulting in the gradual release of some or all of its water.

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

    As water is released, it lowers the melting point of the surrounding rocks and generates magma. This magma is buoyant and moves upwards, ultimately leading to eruptions in the overlying chain of volcanic islands, called a volcanic arc.

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    A seismometer is deployed from the research vessel

    Lead author Dr George Cooper, of the University of Bristol, said: “These eruptions are potentially explosive because of the volatiles (water, carbon dioxide, and sulphur) contained in the melt. The same process can trigger earthquakes and may affect key properties such as their magnitude and whether they trigger tsunamis or not.”

    While most studies look at the Pacific Ring of Fire, the subducting plates that surround the Pacific Ocean, this research focused on the Atlantic plate, in particular on the Lesser Antilles volcanic arc at the eastern edge of the Caribbean Sea.

    Study co-author Professor Jenny Collier, of Imperial’s Department of Earth Science and Engineering, said: “The Lesser Antilles volcanic arc is one of only two zones where we can see these slow-moving plates. We expect this one to be hydrated more pervasively than the fast spreading Pacific plate, and for expressions of water release, like earthquakes and tsunamis, to be more pronounced.”

    To conduct the study, the research team, known as the Volatile Recycling in the Lesser Antilles (VoiLA) project, collected data over two marine scientific cruises. They deployed seismic stations that recorded earthquakes beneath the seafloor and the islands and undertook geological fieldwork, chemical and mineral analyses of rock samples, and numerical modelling.

    To trace the influence of water along the length of the subduction zone, the scientists studied compositions of the element boron and isotopes of melt inclusions (tiny pockets of trapped magma within volcanic crystals). Boron fingerprints revealed that the water-rich mineral serpentine, contained in the sinking plate, is a dominant supplier of water to the central region of the Lesser Antilles arc.

    The researchers say that by studying these microscopic measurements it is possible to better understand large-scale processes. The combined geochemical and geophysical data provide the clearest indication to date that the structure and amount of water of the sinking plate are directly connected to the volcanic evolution of the arc and its associated hazards.

    Co-author Professor Saskia Goes, also of Imperial’s Department of Earth Science and Engineering, said: “The wettest parts of the plate are where there are major cracks (or fracture zones). By making a numerical model of the history of fracture zone subduction below the islands, we found a direct link to the locations of the highest rates of small earthquakes and the presence of fluids in the subsurface.”

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    Installation of seismic stations on the island with University of the West Indies collaborators.

    The history of subduction of water-rich fracture zones can also explain why the central islands of the arc are the largest and why, over geologic history, they have produced the most magma.

    Dr Cooper said: “Our study provides conclusive evidence that directly links the water-in and water-out parts of the cycle and its expressions in terms of magmatic productivity and earthquake activity. This may encourage studies at other subduction zones to find such water-bearing fault structures on the subducting plate to help understand patterns in volcanic and earthquake hazards.”

    Next, the researchers will look into how this pattern of water release may affect the potential for larger earthquakes and possible tsunamis.

    See the full article here .


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    Imperial College London is a science-based university with an international reputation for excellence in teaching and research. Consistently rated amongst the world’s best universities, Imperial is committed to developing the next generation of researchers, scientists and academics through collaboration across disciplines. Located in the heart of London, Imperial is a multidisciplinary space for education, research, translation and commercialisation, harnessing science and innovation to tackle global challenges.

     
  • richardmitnick 9:22 am on June 30, 2020 Permalink | Reply
    Tags: , , Magnitude-5.9 quake is the latest and largest in Tokyo seismic swarm, , Vulcanology   

    From temblor: “Magnitude-5.9 quake is the latest and largest in Tokyo seismic swarm” 

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    From temblor

    June 29, 2020
    Shinji Toda, Ph.D., International Research Institute for Disaster Science, Tohoku University
    Ross Stein, Ph.D., Temblor Inc.

    Six magnitude-5.0+ shocks have struck greater Tokyo since April 1st, part of a larger swarm that extends north to Hokkaido, at a rate that is about three times higher than normal.

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    The recent swarm shocks are shown as stars. Tokyo sits near the junction where three great tectonic plates, the Pacific, Philippine Sea, and Eurasia, meet.

    Tokyo’s seismic past and future

    Earthquakes have long accosted the residents of Tokyo. Most devastating was the magnitude-7.9 1923 Kanto earthquake that killed ~105,000 people, rupturing the megathrust along the Sagami trough. An even larger event struck in 1703. Modern Tokyo and its suburbs are home to one-quarter of Japan’s 127 million population.

    Tokyo is uniquely located where three tectonic plates converge, a setting known as a “triple-junction.” Both the Philippine Sea and Pacific plates are shoved, or subducted, beneath Tokyo, causing megathrust earthquakes on multiple plate interfaces, as well as shallow crustal quakes, and deep earthquakes within the subducting plates.

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    Cross section of seismicity (black dots) beneath Tokyo, which sits in the middle of the Kanto Plain. The Pacific plate (PAC) subducts beneath the Eurasian plate (EUR). We believe that a fragment of the Pacific plate is wedged between the underlying Pacific slab and the overlying Eurasia. Many small and some destructive earthquakes have occurred along the surfaces of the fragment. From Toda et al. (2008).

    To evaluate the seismic hazard, the Japanese government has regularly updated their estimates of large earthquake probabilities since it launched the Headquarters of Earthquake Research Promotion in 1995. The last report announced that the 30-year probability of magnitude-6.7+ quakes for the Tokyo metropolitan area is ~70%.

    The swarm so far

    The recent magnitude-5.0+ earthquakes near metropolitan Tokyo emphasize the high risk of devastating earthquakes. From 1 April 2020 to 28 June, six earthquakes over magnitude-5.0 occurred within ~62 miles (100 kilometers) from the downtown Tokyo (lon. 139.750°/lat. 35.683°), which is two times higher than annual average rate of magnitude-5.0+ quakes since 1950. If this high rate remains, 14 quakes would strike Tokyo by the end of 2020.

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    Six magnitude-5.0+ earthquakes have struck in the Tokyo metro region since 1 April, 2020. The five quakes closest to Tokyo are show here as red stars, along with the epicenters of past earthquakes (blue dots).

    The swarm quakes (red dots) in the above map are occurring in much the same location as past events (blue dots), indicating that the same faults that have slipped in the past are continuing to slip during the swarm. But now, these faults have been activated at a higher rate. We term the current rapid rate of earthquakes a ‘mild swarm,’ because it exceeds the range of natural fluctuation of rate rates. The only comparable period was the year after the 2011 magnitude-9.0 Tohoku earthquake, which transferred a large and sudden pulse of stress to the Kanto region (Ishibe et al., 2011; Toda and Stein, 2013).

    Good news, bad news

    We do not know why the rate of magnitude-5.0+ shocks is increased or whether the ongoing mild swarm could be precursory to a larger catastrophic event. However, the simplest and perhaps most prudent interpretation is that the higher the rate of moderate size quakes accompanies a higher probability of large ones. This assumes that the ratio of small to large quakes has not changed, which, as far as we can tell, is the case.

    A counterargument to our interpretation signals a higher hazard (a higher chance of large events) would be that the swarm quakes indicate that ‘aseismic’ creep is also occurring, as has been recorded off the Boso Peninsula (Uchida and Matsuzawa, 2013). If the magnitude-5.0+ quakes accompany accelerated fault creep, that creep could reduce fault stress. This might then lower the probability of large earthquakes, as advocated by Sommerville (2014).

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    The 1855 Ansei-Edo shock destroyed former Tokyo. Its inferred location and depth coincides with one of the recent magnitude-5.0+ swarm earthquakes. (From Grunewald and Stein, 2006).

    But there is a problem with this interpretation. Several of the swarm quakes struck at a location and depth similar to that of the magnitude~7.2 Ansei-Edo earthquake, which destroyed Edo (former Tokyo) in 1855. That means that the faults beneath Tokyo cannot exclusively creep accompanied by harmless magnitude-5.0 shocks; instead, those faults must also store enough stress to rupture in strong quakes, and so could again. Even if half the inferred slip rate of 1.7 inches per year (~40 millimeters per year) for the slab fragment with respect to the Pacific plate (Toda et al, 2008) is seismic, enough stress has accumulated since 1855 for 9.8 feet (3 meters) of slip, or enough for another deep magnitude-7.2 event.

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    Here is the earthquake forecast issued by Temblor to its commercial clients on 1 June 2020. The impact of the 2011 magnitude-9.0 Tohoku shock, as well as all other magnitude-6.5+ shocks are incorporated into the forecast. Red-yellow sites are expected to have the highest rate of magnitude-5.0 shocks. The 25 Jun 2020 event is consistent with this forecast.

    Even in the time of COVID, we must prepare for quakes

    Even while Japan continues to battle the coronavirus pandemic, as long as the swarm persists, the Japanese should make provisions for the possibility of large earthquakes. Given the great number of people in the Tokyo metropolitan area, we need to plan for shelters that are safe for both natural disasters and coronavirus infection, a daunting prospect.

    Acknowledgements

    We used the JMA and NIED hypocenter data to analyze seismicity with a software package ZMAP (Wiemer, 2001).

    Further Reading

    Grunewald, E., and R. S. Stein (2006), A new 1649-1884 catalog of destructive earthquakes near Tokyo and implications for the long-term seismic process, J. Geophys. Res., 111, doi:10.1029/2005JB004059.

    Headquarters for Earthquake Research Promotion, 2014, Long-term seismic hazard estimates for the regions along the Sagami trough (updated), https://www.jishin.go.jp/main/chousa/kaikou_pdf/sagami_2.pdf. (in Japanese)

    Ishibe, T., K. Shimazaki, K. Satake, and H. Tsuruoka, Change in seismicity beneath the Tokyo metropolitan area due to the 2011 off the Pacific coast of Tohoku Earthquake, Earth Planets Space, 63, 731–735, 201, doi:10.5047/eps.2011.06.001.

    Sommerville, Paul (2014), A post-Tohoku earthquake review of earthquake probabilities in the Southern Kanto District, Japan, Geoscience Lett., 1, 10, doi.org/10.1186/2196-4092-1-10.

    Toda, S., R. S. Stein, S. H. Kirby, and S. B. Bozkurt (2008), A slab fragment wedged under Tokyo and its tectonic and seismic implications, Nature Geoscience, 1, 771-776, doi:10.1038.ngeo318.

    Toda, S. and R. S. Stein, 2013, The 2011 M=9.0 Tohoku oki earthquake more than doubled the probability of large shocks beneath Tokyo, Geophys. Res. Lett., 40, 2562-2566, doi.org/10.1002/grl.50524.

    Uchida N, and T. Matsuzawa, 2013, Pre- and post-seismic slow slip surrounding the 2011 Tohoku-Oki earthquake rupture. Earth Planet Sci. Lett., 374, 81–91, doi: 10.1016/j.epsl.2013.05.021.

    Wiemer, S., 2001, A software package to analyse seismicity: ZMAP, Seismol. Res. Lett. 72, 373– 382, doi.org/10.1785/gssrl.72.3.373.

    See the full article here .


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    Earthquake Alert

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    Earthquake Alert

    Earthquake Network project

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

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

    Get the app in the Google Play store.

    3
    Smartphone network spatial distribution (green and red dots) on December 4, 2015

    Meet The Quake-Catcher Network

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

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

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

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

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

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

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

    BOINC is a leader in the field(s) of Distributed Computing, Grid Computing and Citizen Cyberscience.BOINC is more properly the Berkeley Open Infrastructure for Network Computing, developed at UC Berkeley.

    Earthquake safety is a responsibility shared by billions worldwide. The Quake-Catcher Network (QCN) provides software so that individuals can join together to improve earthquake monitoring, earthquake awareness, and the science of earthquakes. The Quake-Catcher Network (QCN) links existing networked laptops and desktops in hopes to form the worlds largest strong-motion seismic network.

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

    ShakeAlert: An Earthquake Early Warning System for the West Coast of the United States
    1

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

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

    The primary project partners include:

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

    The Earthquake Threat

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

    Part of the Solution

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

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

    System Goal

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

    Current Status

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

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

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

    Authorities

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

    For More Information

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

    Learn more about EEW Research

    ShakeAlert Fact Sheet

    ShakeAlert Implementation Plan

     
  • richardmitnick 9:29 am on June 22, 2020 Permalink | Reply
    Tags: "Clues to the impact of climate change may seep from a volcano in Costa Rica", Another NASA scientist-Florian Schwandner- had been the first one to propose studying carbon fertilization on a tropical volcano’s shoulders., Every year tropical forests soak up more than 2 billion tons of carbon dioxide., , Research suggests that higher concentrations of the gas could actually protect forests., Rincón de la Vieja- an active volcano in Costa Rica, The constant low-level discharges of carbon dioxide from volcanoes might bathe surrounding forests in enough gas to run an enhancement experiment “for free.”, , Vulcanology   

    From The Washington Post via Michigan Tech University: “Clues to the impact of climate change may seep from a volcano in Costa Rica” 

    Michigan Tech bloc

    Michigan Technical University

    From The Washington Post

    June 8, 2020
    Daniel Grossman

    1
    Steam and hot gases rise from the crater of Rincón de la Vieja, an active volcano in Costa Rica. Two scientific teams are measuring the carbon dioxide that seeps from cracks in the volcano’s foundation to determine its impact on the surrounding tropical forest. (Dado Galdieri/Hilaea Media)

    Chad Deering trudges up a dry river channel on the north side of Rincón de la Vieja, one of Costa Rica’s active volcanoes. He wears a baseball cap emblazoned with the phrase Semper Fi, a token of his tour of duty with the Marines, and lugs a peculiar apparatus, part of a sensitive gas-testing kit, that looks more like a metal mixing bowl. The bedrock here is smooth lava, a lifeless tear in the rainforest that blankets Rincón de la Vieja’s flanks.

    Along with two teams of scientists, Deering is pursuing not potential volcanic drama but something imperceptibly gradual — carbon dioxide seeping invisibly from cracks in the volcano’s foundation and exposing the surrounding environment. The question is whether that elevated exposure is a positive, a negative or neither — and what it might mean for the fate of tropical forests globally.

    The stability of the world’s climate depends in part on these areas.

    2

    3

    4
    TOP: Ecologist Josh Fisher, left, and graduate students Nel Rodriguez Sepulveda and Katie Nelson traverse one of Rincón de la Vieja’s slopes. MIDDLE: Graduate students Nel Rodriguez Sepulveda, left, and Katie Nelson walk near the volcano. They and other researchers are measuring carbon dioxide levels around Rincón de la Vieja. BOTTOM: A scientist gauges the airflow in the tropical forest surrounding the volcano. (Dado Galdieri/Hilaea Media)

    Every year, tropical forests soak up more than 2 billion tons of carbon dioxide, a substantial share of what’s emitted by power plants, industrial smokestacks and vehicle exhaust pipes. Yet how increasing temperatures and decreasing rainfall will affect them long term remains unclear.

    While many climate scientists believe that tropical forests will begin to absorb progressively less CO2, other research suggests that higher concentrations of the gas could actually protect them, an idea dubbed carbon fertilization.

    In Costa Rica’s natural laboratory, a dense, steamy tangle in the country’s northwest corner, the teams hope to get closer to the answer. The issue is “one of the biggest uncertainties in climate projections of the fate of the planet,” says NASA scientist Josh Fisher, the ecologist leading the trek. He believes the study “could be a game changer.”

    If extra carbon dioxide revs up Rincón de La Vieja’s jungle, the teams should find bigger trees, more carbon-dense species or some combination where gas levels are particularly high. One group is working on the volcano’s wetter north side and the other on its drier south side, to better assess and then compare two different ecosystems.

    But how to tease out other conditions that also can affect tree growth and the species mix, including altitude and soil moisture? U.S. Forest Service biologist Michael Keller, a tropical forests expert who, though unaffiliated with the project, is following it closely, says such confounding factors make the research a “high risk” experiment.

    Still, he considers it a creative approach to the urgent problem of forecasting the tropical “carbon sink.”

    Research needs data. And on this day, the north-flank team has hit a snag getting it. The river bed has become a deep canyon that abruptly ends beneath sheer walls. The one woman and five men huddle over a computer tablet with a high-resolution map of their intended route.

    Deering, a volcanologist from Michigan Technological University, stabs a finger swollen with bug bites at a spot tantalizingly close but inaccessible. “I want to be here,” he says.

    5
    Graduate student Jacob Bonessi inputs data after measuring carbon dioxide levels around Rincón de la Vieja. (Dado Galdieri/Hilaea Media)

    A crazy idea

    Another NASA scientist had been the first one to propose studying carbon fertilization on a tropical volcano’s shoulders. Several years earlier, Florian Schwandner had helped the Philippines set up a successful network for detecting early symptoms of eruptions of 8,000-foot Mount Mayon, with sensors to track the flow of carbon dioxide from faults in its foundation. (One telltale sign of an oncoming eruption is when that flow suddenly increases.)

    At the space agency’s Jet Propulsion Lab in California, the volcanologist hoped satellite-based measurements of carbon dioxide releases would provide early warnings around the world. His research group was filled with ecologists and frequent discussion of trees’ carbon sink, although nobody knew how to forecast the sink’s future.

    A certain kind of experiment often came up in conversation: spraying extra carbon dioxide into a forest parcel to study how trees respond. Such carbon-enhancement trials had been run often in the United States and in other temperate regions and had shown that extra carbon dioxide sometimes increased forest growth.

    The studies’ relevance for tropical forests was uncertain, but the huge logistical costs of trying to replicate them in remote equatorial areas had been prohibitive.

    An alternative solution dawned on Schwandner in 2016. The constant low-level discharges of carbon dioxide from volcanoes might bathe surrounding forests in enough gas to run an enhancement experiment “for free.” He emailed Fisher, proposing a “compellingly crazy carbon fertilization idea.” Four years later, with funding from NASA, it was finally a go.

    Schwandner, Fisher, and several other scientists and graduate students recruited for the project spent months scouring geological studies and satellite images of Costa Rica, hunting for faults and vents where the 6,286-foot-tall Rincón de la Vieja might be exhaling CO2 onto its rainforest carpet. They pinpointed 16 likely regions.

    Stewing in CO2

    Deep in the jungle, Deering’s team has doubled back, retracing their steps along the river bed and away from the canyon walls. They soon discover a trail near the spot he pointed out. Their local guide, a botanist, says a tapir probably made it foraging for fruit and leaves.

    Deering and graduate student Jacob Bonessi are taking dozens of CO2 measurements daily. They stop not far from a pile of fresh tapir dung. Deering tightly clamps the metal chamber he carries onto a patch of damp jungle soil. An umbilical cord of hoses channels soil exhalations into the apparatus on his back. Buzzing over bird calls, a pump inside the case draws the gas into an instrument that computes the concentration of carbon dioxide wafting up from the ground.

    The pair gaze for a few minutes at the forest’s emerald palms and twined strangler figs. A troop of howler monkeys can be heard in the distance.

    Bonessi checks the reading, displayed on a tablet linked by Bluetooth to the electronics on Deering’s back.

    “What you got?” asks Deering. “One point one four six,” Bonessi answers. “Big time!”

    Deering whoops his enthusiasm. The number is one of the highest they’ve seen.

    6
    Volcanologist Chad Deering walks through the tropical rainforest with a gas-testing kit. (Dado Galdieri/Hilaea Media)

    All over the planet, soil exudes carbon dioxide. It’s a waste product that microbes and subterranean fauna churn out while generating energy from oxygen and nutrients. But what the scientists have detected is well above the background level seeping from the soil here. This is the type of spot, infused with extra carbon dioxide from the volcano’s fractured rock, they were looking for. The trees here are stewing in it.

    The team — traveling only with small backpacks stuffed with lunch, gear for measuring trees and bug repellent — heads to another targeted destination a few minutes uphill. Fisher dons a pair of snake-resistant chaps after a close call with a rattlesnake. Fina Soper, an ecologist and professor at McGill University, wears a custom neckerchief to protect against mosquitoes and ticks. “Badass Biogeochemists,” it reads.

    At each stop, they record the diameter of all trees bigger than a sapling inside a plot the shape and size of a soccer pitch’s center circle. Soper struggles one afternoon with an uncooperative tape measure, a special forester’s rule purchased just for this trip. She loops the metal ribbon around a trunk as broad and true as a Greek temple’s column. But the band won’t retract.

    “It figures that I’d break the most low-tech device I’ve used in my life,” she mutters, tugging on loops of the snarled steel.

    By gathering detailed observations from many sites — each exposed to a unique combination of influences — she and the others are trying to account or control for the factors that influence tree heft. They’ll then tease out the effect of each factor, especially the one that concerns them most: greater carbon dioxide.

    Fisher hopes to vastly ramp up their observations, if this initial expedition pans out, with return trips using one of the most advanced drones flown by NASA. Meanwhile, they painstakingly probe Rincón de la Vieja’s secrets. Ten days of slashing and slogging will yield the diameters of 952 trees between the two groups of scientists. Back home, they’ll calculate the mass of carbon stored in the wood of each plot using standard formulas.

    “It’s good,” Fisher says halfway through the expedition. “Everyone’s healthy. Everyone’s happy. Equipment is working.” But as he well knows, a technical problem could upend the good fortune at any time. And then, he adds with a laugh, “We’ll all be fighting with each other. And everything will go to hell.”

    See the full article here .


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  • richardmitnick 11:42 am on June 19, 2020 Permalink | Reply
    Tags: "Modeling Fluid Migration in Subduction Zones", , , , Vulcanology   

    From Eos: “Modeling Fluid Migration in Subduction Zones” 

    From AGU
    Eos news bloc

    From Eos

    16 June 2020
    Ikuko Wada
    iwada@umn.edu

    Leif Karlstrom

    1
    The Franciscan complex on Santa Catalina Island in California exemplifies the role of fluids in subduction zone processes. In this outcrop, pale beige silicic magmatic dikes crosscut white quartz veins, likely reflecting distinct episodes of hydraulic fracturing of the crust by overpressurized fluids. Image width is about 12 meters. Credit: John Paul Platt

    Some of the biggest challenges in understanding subduction zone processes and their associated hazards arise from the wide range of spatial and temporal scales of the underlying phenomena. Even if we look at the same question—say, how fluid migration affects megathrust faults or volcanic systems—various types of data and models available at different scales often lead to conclusions that are equally relevant but difficult to synthesize or validate.

    To further research efforts on these issues, especially on subduction-related geohazards, a new community initiative called SZ4D has been developed. SZ4D expands upon international research in subduction zone science supported by the National Science Foundation (NSF) Geodynamic Processes at Rifting and Subducting Margins (GeoPRISMS) program, which is in its final stage. Allying with SZ4D, the NSF-funded Modeling Collaboratory for Subduction Research Coordination Network (MCS RCN) organized three workshops focused on identifying research approaches that could lead to more unified subduction science, particularly between volcanic and earthquake processes that historically have been studied independently. The hope is that these activities together will set off a wave of broad rethinking about the future directions of subduction zone science, with an integrated collaboratory to accelerate modeling efforts across disciplines.

    Three Workshops

    The first MCS RCN workshop was held at the University of Minnesota in May 2019 to address fluid migration as a basis for common future research directions across subduction science. With 56 in-person and 90 online participants, we obtained input from a range of Earth scientists, including modelers and observationalists at all career stages.

    The second MCS RCN workshop, on modeling megathrust systems, was held at the University of Oregon in October 2019. And the third workshop, on modeling the subsurface aspects of volcanic systems, was scheduled for summer 2020, but its timing is now unknown.

    The topic of the first workshop—migration of fluids (both aqueous and silicate melts)—is widely recognized as an integral component across subduction zone processes, including megathrust earthquakes like the 2011 Tohoku-Oki earthquake in Japan and volcanic eruptions like the 2019 eruption of Whakaari (White Island) in New Zealand, both of which caused the unanticipated loss of human lives and highlighted gaps in our understanding.

    Current research on the dynamics of multiphase, multicomponent fluid systems is fragmented across many subdisciplines; thus, there are significant opportunities for synergy. Here we build on the outcome of the first workshop by highlighting opportunities and challenges in integrating models across spatial and temporal scales in subduction zones.

    The Challenge of Scale

    Most fluid migration studies focus on subdomains of subduction zones, such as the seismogenic part of the megathrust system, the ductile part of the mantle wedge, and the crustal magma transport system, as defined by the spatial or temporal scales of the processes being studied. This partitioning is artificial from a system-scale standpoint because these subdomains do not operate independently, but it is highly practical given that observations are often limited to restricted scales and the relation between subdomains is difficult to resolve.

    2
    Diagram illustrating key components of a subduction system and models of fluid transport processes for selected subdomains, highlighting different modeling approaches. (a) A dynamic earthquake rupture model showing pore pressure change across a fault (modified from Heimisson et al. [2019]). (b) A tens-of-kilometers-scale model of fluid flow and deformation in a megathrust system (modified from Menant et al. [2019]). (c) A micromechanical model of volume-decreasing dehydration (left) and volume-increasing hydration (right) reactions at mineral grain scale (modified from Okamoto and Shimizu [2015]). (d) A model for fluid circulation in the deforming mantle wedge with varying mineral grain size (magenta contours) and viscosity (yellow contours; modified from Cerpa et al. [2017]). (e) An integrated model for magma ascent from mantle through the lithosphere, showing a vertical strength profile (left), melt fraction (top right), and deviatoric strain rate (bottom right; modified from Keller et al. [2013]). (f) A model for a recharge event into a crystal-rich magma reservoir (modified from Bergantz et al. [2015]). (g) An analogue model for dike-to-sill emplacement in an elastic crust (modified from Kavanagh et al. [2018]). (h) Lumped parameter model for the 2004 Mount St. Helens volcanic eruption from a magma chamber through a volcanic conduit to a surface lava dome (modified from Anderson and Segall [2013]).

    Mathematical models are often developed for a particular set of processes and subdomains with simplifying assumptions that are appropriate for the chosen scale but that may not be appropriate at other scales or in other subdomains. Such simplifications involve relegating unmodeled physical processes to initial and boundary conditions, parameterizing unmodeled processes, or simply ignoring them.

    For example, larger-scale models of megathrust dynamics and arc magmatism must parameterize processes, such as multiphase reactive transport kinetics and fracture mechanics, that occur at smaller scales below the resolution of the numerical simulations. Smaller-scale models often face a similar problem in that they depend on larger-scale estimates of background stress, thermal states, or fluid flux that are not calculated within the smaller models and therefore must be specified on an ad hoc basis. Smaller-scale models might be viewed as elements that eventually fit into integrative models to provide larger-scale predictions, and indeed, one possible realization of the MCS RCN is to produce such a LEGO brick modeling framework.

    Coupling Models and Achieving Consistency

    Meaningfully coupling models is not trivial. Smaller-scale models focused on particular fluid processes in subduction zones are often subject to highly variable observational constraints or even to a lack of observational data. Larger integrative models face challenges involving the computational cost of incorporating processes on all relevant scales, requiring numerical approaches that push the limits of scientific computing.

    One of the key challenges is how to properly couple processes that occur at different spatial and temporal scales. For example, how should the mechanics of slow slip modeled at the meter scale be incorporated in the deformation of the megathrust system that is modeled at a 100-kilometer scale and vice versa? How should elasticity and the brittle behavior of the crust around magma reservoirs and dikes be represented in lithospheric-scale magma migration models? Do unsteady and nonequilibrium effects arising from reactive transport in deformable two-phase media control fluid transport in the mantle wedge? Without the knowledge of how different phenomena influence each other, their overall effects are difficult to quantify.

    Coupling models across different scales or subdomains in a consistent manner requires that we quantify fluid mass flux between domains, but this remains a significant challenge. For example, to predict magma flux into the lithosphere and subsequent volcanism at a narrow arc front or back-arc environment, we must know the permeability structure and melt ascent rates at the lithosphere-asthenosphere boundary. This in turn depends on the production and spatial focusing of melts within the mantle wedge below the boundary, which likely depend on fluid flux from the downgoing slab as well as on the evolving geometry of the lithosphere-asthenosphere boundary. Similarly, in quantifying the buildup of pore fluid pressure and the formation of hydrous phases in the megathrust system, we must know how much of the deep slab-derived fluid migrates within the downgoing material and along the plate interface.

    Analogous issues arise in Earth surface landscape and critical zone evolution models that couple megathrust and volcanic activity to long-term climate. Such problems require an integrated system-scale approach that can resolve evolving plate geometry over millions of years with meters-per-year (or greater) ascent velocities of fluids. Models focused on particular processes (often at a smaller scale) play a crucial role in this development, but identifying the underlying physics and parameter sensitivity must be resolved using integrated models.

    Commonalities in Fluid Migration Problems

    Not all subduction zone subdomains exhibit the same degree of constraints or community consensus regarding validation—challenges that are illustrated by the variability of timing of earthquakes and volcanic eruptions. Both earthquakes and volcanic eruptions occur episodically in response to quasi-steady tectonic forcing (either plate loading or mantle melting) over long timescales. This forcing generates patterns of stress and fluid migration that affect the events’ occurrence and magnitude.

    In volcanology, predictions of crustal magma storage and transport mechanisms that control the eruption cycle depend on poorly understood physical processes. Developing long-term eruption cycle models is thus difficult because of incomplete sampling of the full eruption magnitude-frequency distribution as well as of uncertainties in how to link to long-term constraints from the plutonic record with active volcanism. Earthquake cycle models are more mature in comparison.

    When meaningful commonalities are found, opportunities arise for advancing both earthquake science and volcanology. For example, eruption cycle models might benefit from numerical approaches developed in modeling the multiscale deformation and fluid processes at play in the megathrust system. Likewise, earthquake cycle models could benefit from the multidisciplinary approach that volcanologists have developed to integrate multiscale constraints on fluid transport and storage. Identifying common ground for knowledge sharing and model development is a challenge that determines the practicality of system-scale models.

    Observational Constraints

    To better understand eruption and earthquake cycles or virtually any other grand challenge in subduction zone science, models must grapple with large variability in the degree of observational completeness. For example, one to three approximately magnitude 9 earthquakes occur every 100 years globally [McCaffrey, 2008], but among different faults, recurrence rates are more variable. Global recurrence intervals for the largest subduction-related volcanic eruptions (approximately magnitude 8 or greater based on erupted mass [Pyle, 2015]) are orders of magnitude larger [Rougier et al., 2018] and even more poorly constrained because of sparse records.

    The distributions of smaller events that define earthquake and eruption cycles in terms of magnitude-frequency relationships are also distinct. Along instrumented megathrust faults, earthquakes as small as about magnitude zero can be recorded in some regions (e.g., Nankai, Japan [Nanjo and Yoshida, 2018]). Earthquake cycles also include a spectrum of slow-slip and aseismic-slip events that occur along the megathrust fault systems.

    For arc volcanoes, a similar catalog of recent (Holocene) eruptions is considered complete down to a magnitude of perhaps 4 [Sheldrake and Carrichi, 2017], despite more frequent smaller events globally. This degree of completeness of the volcanic record reflects much poorer recording and preservation of eruptions relative to earthquakes. To complicate matters, pathways of magma ascent often migrate on timescales similar to eruption recurrence intervals. Thus, models for eruption cycles must account for both changing pathways and timescales of magma ascent, whereas megathrust earthquake cycles generally occur on known faults. Such differences in observational constraints represent an outstanding challenge for cross-disciplinary integration of earthquake and volcano science, requiring coordinated community efforts.

    A Modeling Collaboratory

    One vision of the MCS RCN is to identify and use integral components, such as the role of fluids, to unify subduction zone science. At the first workshop, participants agreed that there is a great need to address knowledge gaps among scientists working in different subduction zone subdomains. The MCS RCN’s long-term goal of building a framework of modeling and data analysis tools for subduction zone processes also requires resolving technical disconnects. We can envision a modeling collaboratory to provide a research environment in the form of workshops, training, and community forums to address both of those needs.

    Building community modeling resources, such as approaches for model validation, uncertainty quantification, and benchmarking exercises, is important in disseminating research efforts effectively. The modeling collaboratory could serve as a platform for such activity, but maintaining cross-disciplinary research efforts will require that common objectives among different disciplines be clearly defined. The fluids workshop represented one organizational step toward this goal.

    The full workshop report describes subduction zone–wide research foci from a fluids perspective and possible realizations for future collaborative efforts. A report from the second workshop is forthcoming.

    [Please visit the full article for links to references cited.]

    Acknowledgments

    This article is built on the outcome of the first MCS RCN workshop, held at the University of Minnesota in May 2019, and we thank the workshop participants for their contribution. Special thanks are owed to the writing committee of the workshop report on which this article is partially based: D. Arcay, L. Caricchi, P. Fulton, T. Gerya, K. Iacovino, T. Keller, R. Lauer, G. Lotto, L. Montesi, T. Sun, H. Vrijmoed, and J. Warren. We also thank K. Anderson, G. Bergantz, N. Cerpa, E. Heimisson, J. Kavanagh, T. Keller, A. Menant, and A. Okamoto for providing the plots included in the figure. This article benefited from insightful comments from the MCS RCN Steering Committee and the Writing Committee. L.K. acknowledges support from NSF grant 1848554.

    References

    Anderson, K., and P. Segall (2013), Bayesian inversion of data from effusive volcanic eruptions using physics‐based models: Application to Mount St. Helens 2004–2008, J. Geophys. Res. Solid Earth, 118(5), 2,017–2,037, https://doi.org/10.1002/jgrb.50169.

    Bergantz, G. W., J. M. Schleicher, and A. Burgisser (2015), Open-system dynamics and mixing in magma mushes, Nat. Geosci., 8(10), 793–796, https://doi.org/10.1038/ngeo2534.

    Cerpa, N. G., I. Wada, and C. R. Wilson (2017), Fluid migration in the mantle wedge: Influence of mineral grain size and mantle compaction, J. Geophys. Res. Solid Earth, 122(8), 6,247–6,268, https://doi.org/10.1002/2017JB014046.

    Heimisson, E. R., E. M. Dunham, and M. Almquist (2019), Poroelastic effects destabilize mildly rate-strengthening friction to generate stable slow slip pulses, J. Mech. Phys. Solids, 130, 262–279, https://doi.org/10.1016/j.jmps.2019.06.007.

    Kavanagh, J. L., et al. (2018), Challenging dyke ascent models using novel laboratory experiments: Implications for reinterpreting evidence of magma ascent and volcanism, J. Volcanol. Geotherm. Res., 354, 87–101, https://doi.org/10.1016/j.jvolgeores.2018.01.002.

    Keller, T., D. A. May, and B. J. P. Kaus (2013), Numerical modelling of magma dynamics coupled to tectonic deformation of lithosphere and crust, Geophys. J. Int., 195(3), 1,406–1,442, https://doi.org/10.1093/gji/ggt306.

    McCaffrey, R. (2008), Global frequency of magnitude 9 earthquakes, Geology, 36(3), 263–266, https://doi.org/10.1130/G24402A.1.

    Menant, A., S. Angiboust, and T. Gerya (2019), Stress-driven fluid flow controls long-term megathrust strength and deep accretionary dynamics, Sci. Rep., 9, 9714, https://doi.org/10.1038/s41598-019-46191-y.

    Nanjo, K. Z., and A. Yoshida (2018), A b map implying the first eastern rupture of the Nankai Trough earthquakes, Nat. Commun., 9, 1117, https://doi.org/10.1038/s41467-018-03514-3.

    Okamoto, A., and H. Shimizu (2015), Contrasting fracture patterns induced by volume-increasing and -decreasing reactions: Implications for the progress of metamorphic reactions, Earth Planet. Sci. Lett., 417, 9–18, https://doi.org/10.1016/j.epsl.2015.02.015.

    Pyle, D. (2015), Sizes of volcanic eruptions, in The Encyclopedia of Volcanoes, 2nd ed., edited by H. Sigurdsson et al., chap. 13, pp. 257–264, Academic, Waltham, Mass., https://doi.org/10.1016/B978-0-12-385938-9.00013-4.

    Rougier, J., et al. (2018), The global magnitude–frequency relationship for large explosive volcanic eruptions, Earth Planet. Sci. Lett., 482, 621–629, https://doi.org/10.1016/j.epsl.2017.11.015.

    Sheldrake, T., and L. Caricchi (2017), Regional variability in the frequency and magnitude of large explosive volcanic eruptions, Geology, 45(2), 111–114, https://doi.org/10.1130/G38372.1.

    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.

     
  • richardmitnick 9:12 am on May 1, 2020 Permalink | Reply
    Tags: "Can rain trigger a volcanic eruption?", , Copernicus Sentinel-1, , , Vulcanology   

    From European Space Agency – United Space in Europe: “Can rain trigger a volcanic eruption?” 

    ESA Space For Europe Banner

    From European Space Agency – United Space in Europe

    30-04-2020

    1
    Lava from Kilauea’s last remaining active fissure erupts in what used to be the Leilani Estates neighborhood, near Pahoa, Hawaii, on July 14, 2018. U.S. Geological Survey/AP.

    The notion that rain could lead to a volcanic eruption may seem strange, but scientists from the University of Miami in the USA, have used information from satellites, including the Copernicus Sentinel-1 mission, to discover that a period of heavy rainfall may have triggered the four month-long eruption of Hawaii’s Kilauea volcano in 2018.

    ESA Sentinel-1B

    Producing about 320 000 Olympic-sized swimming pools’ worth of lava that reshaped the landscape, destroyed hundreds of homes and caused the collapse of the summit caldera, the 2018 eruption was one of the most destructive in Kilauea’s recorded history.

    A paper published recently in Nature proposes a new model to explain why this eruption happened. The authors, Jamie Farquharson and Falk Amelung from the University of Miami’s Rosenstiel School of Marine & Atmospheric Science, suggest that heavy rainfall may have been the culprit.

    In the months before the eruption, Hawaii was inundated by an unusually prolonged period of heavy, and at times extreme, rainfall.

    The rainwater would have found its way through the pores of the volcanic rock and increased the pressure within – decreasing the rigidity of the rock and allowing magma to rise to the surface.

    Falk Amelung said, “We knew that changes in the water content in the Earth’s subsurface can trigger earthquakes and landslides. Now we know that it can also trigger volcanic eruptions. Under pressure from magma, wet rock breaks easier than dry rock. It is as simple as that.”

    Using a combination of ground-based and satellite measurements of rainfall, Farquharson and Amelung modelled the fluid pressure within the volcano’s edifice over time – a factor that can directly influence the tendency for mechanical failure in the ground, ultimately driving volcanic activity.

    2
    Pre-eruption ground deformation

    This is not an entirely new theory, but it was previously thought that this could only happen at shallow depths. Here, the scientists conclude that the rain increased pore pressure deep down – at depths of up to 3 km.

    The team’s results highlight that fluid pressure was at its highest in almost half a century immediately prior to the eruption, which they propose facilitated magma movement beneath the volcano. Their hypothesis also explains why there was relatively little widespread uplift around the volcano in the months prior.

    “We would normally see the ground inflate, or ‘uplift’ before an eruption as the magma chamber swells. We used radar information from the Copernicus Sentinel-1 mission to see that the amount of inflation was low.

    “This lack of substantial inflation suggests that the intrusion–eruption could not only have been triggered by an influx of fresh magma from depth, but that it was caused by a weakening of the rift zone. The six-day repeat observations from the Sentinel-1 mission were key to our research.

    “A fact that must be considered when assessing volcanic hazards is that increasing extreme weather patterns associated with ongoing anthropogenic climate change could also increase the potential for rainfall-triggered volcanic activity.”

    The Copernicus Sentinel-1 mission is a constellation of two identical radar satellites offering the capability to monitor ground deformation with the technique of interferometry. The constellation provides the capability to image part of the globe in the same geometry every six days – a repeat that is ensured for the Group on Earth Observation’s Geohazard Supersites, to which Hawaii islands belong.


    Monitoring changing land with Sentinel-1. ESA.

    See the full article here .


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    Please help promote STEM in your local schools.

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 11:37 am on March 20, 2020 Permalink | Reply
    Tags: "U.S. Readies Health Response for the Next Big Eruption", , , , , Mount St. Helens spawned a new field of science concerned with the health impacts of volcanoes in the short and long term., Volcano experts meet regularly to discuss eruption forecasting and hazard modeling., Vulcanology   

    From Eos: “U.S. Readies Health Response for the Next Big Eruption” 

    From AGU
    Eos news bloc

    From Eos

    12 March 2020
    Kimberly M. S. Cartier

    Forty years after the explosive eruption of Mount St. Helens, scientists, communities, and civic officials are evaluating plans to best protect public health before, during, and after an eruption.

    1
    A Plinian eruption column billows from Mount St. Helens on 18 May 1980. Credit: USGS/Robert Krimmel.

    Whakaari volcano in New Zealand erupted on 9 December 2019. Although experts had warned for weeks that the stratovolcano was showing signs of unrest, Whakaari remained open to tourism. Forty-seven people were reported to have been on Whakaari, or White Island, when the eruption happened. Twenty-one people have died.

    A month later, Taal volcano in the Philippines erupted and spewed a 15-kilometer tall ash plume into the sky. Lava fountains, sulfuric gas, volcanic earthquakes, and more ash plumes followed. Nearly half a million people lived within the 14-kilometer radius danger zone, but only about 70,000 of those people are estimated to have sheltered in evacuation centers. The price of certified breathing masks inflated tenfold after the eruption. The Philippine Department of Agriculture estimated that ash has destroyed roughly US$60 million in crops. Some residents of Taal have lost everything.

    “We live on a very, very active planet volcanically speaking,” said Janine Krippner, a volcanologist at the Smithsonian Global Volcanism Program in Washington, D.C. “Those types of volcanoes and the eruption styles that we’ve seen now could absolutely happen in the United States in a wide range of sizes—from White Island being very small [to] Taal being a moderate eruption which has the potential to be bigger,” she said.

    It has been 40 years since Mount St. Helens in Washington state erupted. On 18 May 1980, the event killed 57 people, including a volcanologist monitoring the ongoing activity. Since then the volcano experienced some sustained eruptive activity between 2004–2008, largely creating a lava dome beneath the surface, but occasionally sending up some ash. That means it’s been 40 years since U.S. agencies have had to coordinate to keep a major eruption on the mainland from becoming a public health crisis—and experts have found that it’s long past time for a more modern game plan.

    It’s About Who You Know…

    A lot of recent interagency work has focused on bringing volcano response plans in line with the newest science, response structures, and communication platforms.

    Regional and state emergency divisions have kept an ongoing dialogue with the Cascades Volcano Observatory (CVO) on the hazards specific to their areas. The National Science Foundation, NASA, the U.S. Geological Survey (USGS), and the National Academies of Sciences, Engineering, and Medicine conducted a 2-year investigation about how to improve eruption forecasting. Volcanologists, too, have been developing a research coordination network to organize scientific investigations of an eruption, which will inform future response plans.

    In 2018, the eruption of Kīlauea in Hawaii became a proving ground for some of these new response networks.

    3
    Lava bursts from a fissure on the flanks of Kīlauea volcano. As new lava flows and as Kilauea evolves, new landscapes in southeastern areas of the island of Hawai‘i are beginning to take shape. Credit: Mario Tama/Staff/Getty Images News/Getty Images

    Local response teams, USGS, the Federal Emergency Management Agency, and scientists worked together to gather and disseminate information to affected populations. Many of those involved consider the overall response a great success.

    Volcano experts meet regularly to discuss eruption forecasting and hazard modeling. But there’s still more work to be done in understanding the health risks form volcanoes and coming up with action plans to mitigate those risks.

    In the current framework, response would start at the city level, the Centers for Disease Control and Prevention’s Agency for Toxic Substances and Disease Registry (CDC ATSDR) told Eos in a statement. “Local authorities could declare an emergency or disaster and likely would request state assistance. The governor of the state would request federal help if needed. The state request could prompt a presidential declaration and the National Response Framework would activate under the Federal Emergency Management Agency (FEMA).” The National Response Framework, a federal guide to disaster and emergency response, was not in place when Mount St. Helens erupted but has since been used to guide the response to eruptions in Alaska, Hawaii, and the Philippines, ATSDR said.

    “At the eruption of Mount St. Helens in 1980…there were many agencies and thousands of individuals involved in all aspects of the disaster,” explained Peter Baxter, a volcano health expert at the University of Cambridge in the United Kingdom. Baxter, who was part of the response team in 1980, said that the eruption was an “unknown entity” in terms of the human health impacts and the practical challenges of ash deposits in community.

    “People had to learn from scratch,” he said. “Although some of the lessons have been relearned at other volcanoes around the world since, a lot of valuable practical experience is being lost as people retire.”

    “When you do disaster response work, you want to have relationships in place,” said David Damby, who researches the health impacts of eruptions at the USGS California Volcano Observatory in Menlo Park. “During a crisis it’s really hard to meet people and spin up a working relationship on the spot.” If an emergency manager needs a particular piece of information about an ongoing disaster, he said, the key to responding quickly is knowing ahead of time who holds that information.

    …And Also What You Know

    Before the Mount St. Helens event, the last time a major volcano had erupted in the conterminous United States was the 1914 Lassen Peak eruption in California. Unlike the very active volcanoes in Hawaii and Alaska, active volcanoes in the rest of the country erupt twice a century on average. That makes it difficult to predict the potential health hazards that stem from any one specific volcano.

    Mount St. Helens spawned a new field of science concerned with the health impacts of volcanoes in the short and long term. As far as case studies go, that eruption is still one of the most extensively studied to date, but it’s still just one example of the type of eruption that might take place. Volcanologists, out of necessity, study examples from around the world to learn more about what the next Cascades eruption might look like.

    “There was an eruption of El Chichón in 1982 in southern Mexico, and 1,500 people died from pyroclastic flows,” said Carolyn Driedger. “People were not organizing. They had not built trusting relationships with their local communities at risk.” Driedger, a hydrologist and outreach coordinator at CVO in Vancouver, Wash., also witnessed and responded to the Mount St. Helens eruption.

    Then came the eruption of Nevado del Ruiz, Colombia, in 1985 and the Armero tragedy, in which more than 20,000 people in the city of Armero died as a result of mudflows issuing from the eruption.

    “Scientists came into [Armero] and tried to talk to local people, but…they weren’t trusted,” Driedger said. “There were vested business interests that were interfering with the messaging. The lahar came through.”

    A lahar is a volcanic mudflow, Driedger explained. “It’s debris and mud and boulders and anything the flow can pick up and carry.”

    “It was just your worst nightmare,” she said. “It was a dark and stormy night, 11:30 at night, when the lahar came through; 25,000 people died. That showed us lahars are huge hazards and getting information about these hazards to people is so important.”

    From the 1991 eruption of Pinatubo, Philippines, “we learned a lot about eruption prediction and how lahars can affect areas for generations after the initial occurrence,” Driedger said. “Now we know it’s not over when it’s over.”

    Other scientific disciplines aid volcanic research, too. “There’s been a lot done on anthropogenic pollution, for example,” Damby said. “Understanding the impact of particulate matter on people’s health is something that we’re really tuned into because volcanic ash, at the end of the day, is particulate matter.”

    Volcanologists have spent decades building a body of knowledge about how a volcanic eruption might make people sick. That knowledge can be of critical use to agencies and health professionals who don’t exclusively deal with volcanoes.

    “If you’re a health professional who’s never dealt with a volcanic eruption before—which anyone in the U.S. who didn’t respond to 1980 Mount St. Helens is in that same boat—then it’s nice to be able to have the USGS say, ‘Here’s what we know. Here’s what problems might be. Here’s what we need to test for,’” Damby said.

    Evolving Eruptions

    However, predicting an eruption’s hazards is not as easy as saying “Volcano X will produce Hazard X” and “Volcano Y will produce Hazard Y.”

    “Volcanic eruptions can evolve,” Krippner said. “They can get bigger or smaller, or they can pause and then continue. The different hazards can change through that time as well and the extent of those hazards.”

    Disaster mitigation plans work best when the people at risk understand those risks. “There are areas which are excelling at this, but generally speaking, every single aspect of volcanism seems to be misunderstood,” she said.

    For example, simply using the word “smoke” instead of “ash” implies a different set of health hazards and protection measures. “I’d say everything—the terminology, what the hazards are, what they mean for people, what the impacts to people actually are, and how people can stay safe—every single aspect of volcanology has to be better understood by the community,” said Krippner. She noted that official communications about the 2018 Kīlauea eruption were superb.

    “What we focus on the most, because it puts the most people in immediate harm’s way, is lahars,” said Brian Terbush, who heads the earthquake and volcano program at the Washington State Emergency Management Division.

    “All of our volcanoes have a lahar potential and especially the larger ones with huge glacier cover that have river drainages that go into populated areas, such as Mount Rainier,” Terbush said. “About 80,000 people could potentially be at risk from the lahars.” That’s just those at risk from the most immediate lahars near Mount Rainier, Terbush said. Downriver lahars, some experts say, could endanger more than 100,000 residents, employees, and tourists.

    “They are highly destructive,” Driedger added, “so it’s maybe less a health hazard and more a matter of life and death as to your getting out of the way.”

    4
    An eruption of Mount Rainier would cause lahars to sweep through the surrounding area and toward the Puget Sound. Many of the cities at risk for lahars plan and practice evacuation routes. Credit: USGS

    And then, of course, there is volcanic ash. “When ash falls, everything that is covered is impacted and that includes the air,” she said. “Most of the time ash is a nuisance to people, but the people who already have compromised breathing are at risk just as they would be in a place with dense pollution or smoke in the air or a dust storm.”

    Volcanologists and emergency responders are using ash dispersion models, like Ash3d, more often. These models use weather data from the National Oceanic and Atmospheric Administration (NOAA) to predict what areas might experience ashfall. Information from NOAA is also needed after an eruption has ended, when ash can be resuspended in the air by wind and continue to endanger people with compromised breathing.

    “When an eruption is developing, it’s a very confusing time,” Krippner said. “There’s a lot of conflicting information. Scientists are figuring out what exactly is happening, how big this eruption might be, and what areas are being impacted. The groundwork needs to be done beforehand.”

    It’s Not Over When It’s Over

    There’s still a lot of work to be done assessing the long-term health impacts of an eruption, including the secondary health impacts that can occur long before or long after an eruption.

    The sometimes-prolonged period of anticipation preceding an eruption can affect the mental health of emergency managers and the at-risk population. “Even before the lahar even happens…there’s the mental stress of knowing what can happen in your beloved community. I don’t discount that as a medical issue,” Driedger said.

    Sometimes eruptions build up slowly over months, Terbush added, but sometimes they can escalate in a matter of hours (as happened with Taal). For emergency managers, “just the unpredictability of what’s actually going to happen in an eruption, unpredictability in the timeline and unpredictability of which hazards are going to be impactful… if people are activated and responding, especially media response for all that time, that is going to wear on everybody involved.”

    And then there are the myriad of ways that ashfall, lahars, and, to a lesser extent, lava flows, damage critical infrastructure that protects public health. “All the health issues related to relocations—not just temporary evacuation but in many cases final relocation—all those health issues, mental and physical, are applicable with lahars,” Driedger said.

    Ashfall and lahars can cause power outages and leave hospitals and at-home medical devices without power. Wet ash slicks roads and reduces visibility, which can lead to car accidents. Ash can damage a plane’s jet engines, which can hinder evacuation and relief efforts, she added. Local transit authorities, the U.S. Department of Transportation, or the National Guard might aid an evacuation.

    Toxic salts, or leachates, can form on ash while its still in the plume and then wash out into groundwater after ashfall. Livestock that eat contaminated grass or soil can get sick or die.

    “It’s easy to just say ash is ash is ash,” Damby said. “But depending on the composition of the volcano that it erupted from, each ash sample will differ from every other ash sample erupted at a different volcano.” Ash particles around 2.5 and 10 micrometers in size are particularly bad for respiratory health.

    Lahars sweep away bridges, buildings, cropland, and forests, and they can also threaten the local water supply for years. “Lahars are the lasting legacy of volcanic eruptions,” Driedger said. Lahar damage to water treatment plants can lead to higher disease rates. Sediment that is resuspended in water and moved down the valley can keep land unsuitable for settling for generations, she said. Agencies like the CDC, National Institutes of Health, U.S. Department of Agriculture, and Environmental Protection Agency might be called upon to assess land and water toxicity and help recovery efforts.

    And although lava generally moves slow enough that people can get out of the way, lava flows “can gobble up plenty of good orchard and agricultural space that can impact people,” Driedger added. “When you impact personal economies or the economy of the community, you are impacting the health of the people within it.”

    Plan, Practice, Educate, Communicate

    In the time between the recent Whakaari and Taal eruptions, there were actually dozens of volcanoes erupting around the world. “So to only have two making the news in a month or so shows you how little people are actually aware of the amount of activity we have on this planet,” Krippner said.

    Moreover, the unpredictability of eruption hazards presents a challenge for putting together an effective response plan, Terbush said. “Overall, there’s been a shift at the county and local levels with the recognition that any volcanic disaster is going to affect every area a little bit differently.” In areas that were affected by Mount St. Helens and those in the possible path of lahars, there is a cultural awareness of the dangers people might face.

    “The city of Puyallup has been excellent [in volcano readiness],” Terbush said. “This is one of the [municipalities] immediately in Mount Rainier’s lahar zone. This past year they evacuated 9,000 students, did a full school drill of 20 schools.” The drill, which took place on 17 May 2019, was the largest volcano evacuation drill in U.S. history.

    Volcano hazard work groups throughout the Cascade region bring emergency managers from local, regional, state, and tribal areas together with volcano experts to develop coordinated action plans. More cities every year practice lahar evacuation plans like Puyallup’s. Regional volcano observatories work with policy makers to make land use decisions that consider volcano hazards.

    But Driedger argues that volcano awareness and preparedness cannot end at the borders of Washington and Oregon. “Volcanic eruptions are pretty much out of the modern-day person’s personal experience,” she said. “Earthquakes you can feel—you know what a rumble is. You understand the concept of flooding or of a wind storm or a snow storm. But with volcanoes, they’re so multifaceted. It takes an extra amount of effort for us to talk about it with people and get them to understand. They fail to recognize that an eruption in Alaska can affect them in Wisconsin.”

    “We live in such a global society now, too,” she added. “People come to volcanic areas, and they don’t understand what the threats are….It’s the residents and it’s people who visit there, and it’s the taxpayers who are all funding risk reduction measures in some way or another.”

    Raising the base-level understanding of volcano hazards, Krippner said, will also go a long way toward combating the deluge of misinformation that spreads around the globe at lightning speed. In a crisis, finding good information fast saves lives.

    “If we have more sources of information that are consistent, easy to find, and [distributed] in more ways,” Krippner said, “and if we have people with larger followings out there that can point to these things rapidly, I think that would begin to solve the problem.”

    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.

     
  • richardmitnick 5:40 pm on February 18, 2020 Permalink | Reply
    Tags: "South American volcano showing early warning signs of 'potential collapse' research shows", , , , Tungurahua volcano in Ecuador – known locally as “The Black Giant”, University of Exeter, Vulcanology   

    From University of Exeter: “South American volcano showing early warning signs of ‘potential collapse,’ research shows” 

    1

    From University of Exeter

    One of South America’s most prominent volcanoes is producing early warning signals of a potential collapse, new research has shown [Earth and Planetary Science Letters].

    1
    Credit: CC0 Public Domain

    Tungurahua volcano in Ecuador – known locally as “The Black Giant” – is displaying the hallmarks of flank instability, which could result in a colossal landslide.

    New research, led by Dr James Hickey from the Camborne School of Mines, has suggested that the volcano’s recent activity has led to significant rapid deformation on the western flank.

    The researchers believe that the driving force causing this deformation could lead to an increased risk of the flank collapsing, causing widespread damage to the surrounding local area.

    The research recommends the volcano should be closely monitored to watch for stronger early warning signs of potential collapse.

    The study is published in the journal Earth & Planetary Science Letters.

    Dr Hickey, who is based at the University of Exeter’s Penryn Campus, Cornwall, said: “Using satellite data we have observed very rapid deformation of Tungurahua’s west flank, which our research suggests is caused by imbalances between magma being supplied and magma being erupted”.

    Tungurahua volcano has a long history of flank collapse, and has also been frequently active since 1999. The activity in 1999 led to the evacuation of 25,000 people from nearby communities.

    A previous eruption of Tungurahua, around 3,000 years ago, caused a prior, partial collapse of the west flank of the volcanic cone.

    This collapse led to a wide-spread debris avalanche of moving rock, soil, snow and water that covered 80 square kilometres – the equivalent of more than 11,000 football fields.

    Since then, the volcano has steadily been rebuilt over time, peaking with a steep-sided cone more than 5000 m in height.

    However, the new west flank, above the site of the 3000 year old collapse, has shown repeated signs of rapid deformation while the other flanks remain stable.

    The new research has shown that this deformation can be explained by shallow, temporary magma storage beneath the west flank. If this magma supply is continued, the sheer volume can cause stress to accumulate within the volcanic cone – and so promote new instability of the west flank and its potential collapse.

    Dr Hickey added: “Magma supply is one of a number of factors that can cause or contribute to volcanic flank instability, so while there is a risk of possible flank collapse, the uncertainty of these natural systems also means it could remain stable. However, it’s definitely one to keep an eye on in the future.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    2

    The University of Exeter is a public research university in Exeter, Devon, South West England, United Kingdom. It was founded and received its royal charter in 1955, although its predecessor institutions, St Luke’s College, Exeter School of Science, Exeter School of Art, and the Camborne School of Mines were established in 1838, 1855, 1863, and 1888 respectively.[5][6] In post-nominals, the University of Exeter is abbreviated as Exon. (from the Latin Exoniensis), and is the suffix given to honorary and academic degrees from the university.

    The university has four campuses: Streatham and St Luke’s (both of which are in Exeter); and Truro and Penryn (both of which are in Cornwall). The university is primarily located in the city of Exeter, Devon, where it is the principal higher education institution. Streatham is the largest campus containing many of the university’s administrative buildings[7] The Penryn campus is maintained in conjunction with Falmouth University under the Combined Universities in Cornwall (CUC) initiative. The Exeter Streatham Campus Library holds more than 1.2 million physical library resources, including historical journals and special collections.[8]

    Exeter was named the Sunday Times University of the Year in 2013[9] and was the Times Higher Education University of the Year in 2007.[10] It has maintained a top ten position in the National Student Survey since the survey was launched in 2005.[11] The annual income of the institution for 2017–18 was £415.5 million of which £76.1 million was from research grants and contracts, with an expenditure of £414.2 million.[1]

    Exeter is a member of the Russell Group of leading research-intensive UK universities[12] and is also a member of Universities UK, the European University Association, and the Association of Commonwealth Universities and an accredited institution of the Association of MBAs (AMBA).

     
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