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4. Mercury records covering the past 90 000 years from lakes Prespa and Ohrid, SE Europe

Author

Paine, Alice R., Fendley, Isabel M., Frieling, Joost, Mather, Tamsin A., Lacey, Jack H., Wagner, Bernd, Robinson, Stuart A., Pyle, David M., Francke, Alexander, Them II, Theodore R., Panagiotopoulos, Konstantinos, Paine, Alice R., Fendley, Isabel M., Frieling, Joost, Mather, Tamsin A., Lacey, Jack H., Wagner, Bernd, Robinson, Stuart A., Pyle, David M., Francke, Alexander, Them II, Theodore R., and Panagiotopoulos, Konstantinos

Abstract

The element mercury (Hg) is a key pollutant, and much insight has been gained by studying the present-day Hg cycle. However, many important processes within this cycle operate on timescales responsive to centennial- to millennial-scale environmental variability, highlighting the importance of also investigating the longer-term Hg records in sedimentary archives. To this end, we here explore the timing, magnitude, and expression of Hg signals retained in sediments over the past ∼ 90 kyr from two lakes, linked by a subterranean karst system: Lake Prespa (Greece, North Macedonia, and Albania) and Lake Ohrid (North Macedonia and Albania). Results suggest that Hg fluctuations are largely independent of variability in common host phases in each lake, and the recorded sedimentary Hg signals show distinct differences first during the Late Pleistocene (Marine Isotope Stages 2–5). The Hg signals in Lake Prespa sediments highlight an abrupt, short-lived peak in Hg accumulation coinciding with local deglaciation. In contrast, Lake Ohrid shows a broader interval with enhanced Hg accumulation and, superimposed, a series of low-amplitude oscillations in Hg concentration peaking during the Last Glacial Maximum, which may result from elevated clastic inputs. Divergent Hg signals are also recorded during the Early and Middle Holocene (Marine Isotope Stage 1). Here, Lake Prespa sediments show a series of large Hg peaks, while Lake Ohrid sediments show a progression to lower Hg values. Since ∼ 3 ka, anthropogenic influences overwhelm local fluxes in both lakes. The lack of coherence in Hg accumulation between the two lakes suggests that, in the absence of an exceptional perturbation, local differences in sediment composition, lake structure, Hg sources, and water balance all influence the local Hg cycle and determine the extent to which Hg signals reflect local- or global-scale environmental changes.

Published
2024

5. Identification of the Mechanism Resulting in Regions of Degraded Toughness in A508 Grade 4N Manufactured Using Powder Metallurgy–Hot Isostatic Pressing.

Author

Ridgeway, Colin D., Nolan, Terrance, and Pyle, Joeseph M.

Subjects
ISOSTATIC pressing, LOW alloy steel, PARTICLE size distribution, CRYSTAL grain boundaries, POWDERS
Abstract

Powder metallurgy–hot isostatic pressing (PM-HIP) is a form of advanced manufacturing that offers the ability to produce near-net shape components that are otherwise not achievable via conventional forging or wrought manufacturing. Accessing the design space of PM-HIP is dependent upon the ability to achieve uniform or known properties in finalized components, which has resulted in a number of programs aimed at identifying properties achievable via PM-HIP manufacturing. One result of these programs has been the consistent observation of a variation in toughness observed for the low-alloy steel ASTM A508 Grades 3 and 4N. While observed, the degree of variability and the mechanism resulting in the variability have not yet been fully defined. Thus, a systematic approach to evaluate the variation observed in impact toughness in PM-HIP ASTM A508 Grade 4N was proposed to elucidate the responsible metallurgical mechanism. Four unique billets manufactured from two heats of powder with different particle size distributions (PSDs) were fabricated and tested for impact toughness and tensile properties. The degradation in impact toughness was confirmed to be location-specific where the near-can region of all billets had reduced impact toughness relative to the interior of each billet. The mechanism driving the location-specific property development was identified to be mobile oxygen that follows the thermal gradient that develops during the HIP cycle and leads to a redistribution of mobile oxygen where oxygen is concentrated ~1" inboard of the original canister/billet interface. Redistributed oxygen then forms stable oxides along coincident prior particle and prior austenite grain boundaries, effectively reducing the impact toughness. With the mechanism now addressed, necessary actions can be taken to mitigate the effect of the oxygen redistribution, allowing for use in PM-HIP A508 Grade 4N in commercial industry. [ABSTRACT FROM AUTHOR]

Published
2024
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14. Supplementary material to "Mercury records covering the past 90 kyr from lakes Prespa and Ohrid, SE Europe"

Author

Paine, Alice R., primary, Fendley, Isabel M., additional, Frieling, Joost, additional, Mather, Tamsin A., additional, Lacey, Jack H., additional, Wagner, Bernd, additional, Robinson, Stuart A., additional, Pyle, David M., additional, Francke, Alexander, additional, Them II, Theodore R., additional, and Panagiotopoulos, Konstantinos, additional

Published
2023
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17. Mercury records covering the past 90 000 years from lakes Prespa and Ohrid, SE Europe.

Author

Paine, Alice R., Fendley, Isabel M., Frieling, Joost, Mather, Tamsin A., Lacey, Jack H., Wagner, Bernd, Robinson, Stuart A., Pyle, David M., Francke, Alexander, Them II, Theodore R., and Panagiotopoulos, Konstantinos

Subjects
LAST Glacial Maximum, MERCURY, LAKES, LAKE sediments, COMPOSITION of sediments
Abstract

The element mercury (Hg) is a key pollutant, and much insight has been gained by studying the present-day Hg cycle. However, many important processes within this cycle operate on timescales responsive to centennial- to millennial-scale environmental variability, highlighting the importance of also investigating the longer-term Hg records in sedimentary archives. To this end, we here explore the timing, magnitude, and expression of Hg signals retained in sediments over the past ∼ 90 kyr from two lakes, linked by a subterranean karst system: Lake Prespa (Greece, North Macedonia, and Albania) and Lake Ohrid (North Macedonia and Albania). Results suggest that Hg fluctuations are largely independent of variability in common host phases in each lake, and the recorded sedimentary Hg signals show distinct differences first during the Late Pleistocene (Marine Isotope Stages 2–5). The Hg signals in Lake Prespa sediments highlight an abrupt, short-lived peak in Hg accumulation coinciding with local deglaciation. In contrast, Lake Ohrid shows a broader interval with enhanced Hg accumulation and, superimposed, a series of low-amplitude oscillations in Hg concentration peaking during the Last Glacial Maximum, which may result from elevated clastic inputs. Divergent Hg signals are also recorded during the Early and Middle Holocene (Marine Isotope Stage 1). Here, Lake Prespa sediments show a series of large Hg peaks, while Lake Ohrid sediments show a progression to lower Hg values. Since ∼ 3 ka , anthropogenic influences overwhelm local fluxes in both lakes. The lack of coherence in Hg accumulation between the two lakes suggests that, in the absence of an exceptional perturbation, local differences in sediment composition, lake structure, Hg sources, and water balance all influence the local Hg cycle and determine the extent to which Hg signals reflect local- or global-scale environmental changes. [ABSTRACT FROM AUTHOR]

Published
2024
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19. Mercury records covering the past 90 kyr from lakes Prespa and Ohrid, SE Europe

Author

Paine, Alice R., Fendley, Isabel M., Frieling, Joost, Mather, Tamsin A., Lacey, Jack H., Wagner, Bernd, Robinson, Stuart A., Pyle, David M., Francke, Alexander, Them II, Theodore R., and Panagiotopoulos, Konstantinos

Abstract

The element mercury (Hg) is a key pollutant, and much insight has been gained by studying the present-day Hg cycle. However, many important processes within this cycle operate on timescales responsive to centennial to millennial-scale environmental variability, highlighting the importance of also investigating the longer-term Hg records in sedimentary archives. To this end, we here explore the timing, magnitude, and expression of Hg signals retained in sediments over the past ~90 ka from two lakes, linked by a subterranean karst system: Lake Prespa (Greece/North Macedonia/Albania) and Lake Ohrid (North Macedonia/Albania). Results suggest that Hg fluctuates largely independent of variability in common host phases in each lake, and the recorded sedimentary Hg signals show distinct differences first during the late Pleistocene (Marine Isotope Stages 2–5). The Hg signals in Lake Prespa sediments highlights an abrupt, short-lived, peak in Hg accumulation coinciding with local deglaciation. In contrast, Lake Ohrid shows a broader interval with enhanced Hg accumulation, and, superimposed, a series of low-amplitude oscillations in Hg concentration peaking during the Last Glacial Maximum, that may result from elevated clastic inputs. Divergent Hg signals are also recorded during the early and middle Holocene (Marine Isotope Stage 1). Here, Lake Prespa sediments show a series of large Hg peaks; while Lake Ohrid sediments show a progression to lower Hg values. Around 3 ka, anthropogenic influences overwhelm local fluxes in both lakes. The lack of coherence in Hg accumulation between the two lakes suggests that, in the absence of an exceptional perturbation, local differences in sediment composition, lake structure, and water balance all influence the local Hg cycle, and determine the extent to which Hg signals reflect local or global-scale environmental changes.

Published
2023

25. List of Contributors

Author

Abdullah, Anthony, primary, Abrouk, Michael, additional, Ahad, Tashmeeta, additional, Ahmed, Imtiaz, additional, Al Hammadi, Anwar, additional, Allen, Caroline, additional, Almohssen, Amer Ali, additional, Alwan, Wisam, additional, Ameen, Mahreen, additional, Amini, Sadegh, additional, Anderson, Bryan E., additional, Anhalt, Grant J., additional, Baker, Donald J., additional, Bala, Harini Rajgopal, additional, Baltz, Julia, additional, Banach, David, additional, Banfield, Cedric C., additional, Baran, Robert, additional, Bardhan, Ajoy, additional, Barkham, Melissa C., additional, Bello, Ysabel M., additional, Benton, Emma, additional, Bergfeld, Wilma F., additional, Berkowitz, Eric, additional, Berman, Brian, additional, Bernhard, Jeffrey D., additional, Bernstein, Daniel, additional, Berth-Jones, John, additional, Bhate, Chinmoy, additional, Bhatia, Bhavnit K., additional, Blume, Jonathan E., additional, Bordet, Nevianna, additional, Borysiewicz, Catherine, additional, Brauner, Gary J., additional, Brodell, Robert T., additional, Brown, Marc D., additional, Burd, Robert M., additional, Burdick, Anne E., additional, Butala, Niraj, additional, Callen, Jeffrey P., additional, Camacho, Ivan D., additional, Camasmie, Helena, additional, Caplivski, Daniel, additional, Cappell, Mitchell S., additional, Casey, Genevieve A., additional, Chan, Lawrence S., additional, Chan, Loi-Yuen, additional, Chen, Jennifer K., additional, Chen, Chen “Mary”, additional, Chiang, Nicole Yi Zhen, additional, Chiaravalloti, Anthony J., additional, Child, Fiona J., additional, Chu, Anthony C., additional, Clayton, Timothy H., additional, Cohen, Steven R., additional, Cooper, Elizabeth A., additional, Cooper, Susan M., additional, Collier, Nick, additional, Correnti, Christina M., additional, Coulson, Ian H., additional, Council, M. Laurin, additional, Cowper, Shawn E., additional, Craven, Nicholas M., additional, Creamer, Daniel, additional, Cruz, Ponciano D., additional, Cusack, Carrie Ann R., additional, Daunton, Adam, additional, Davis, Mark D.P., additional, Dawe, Robert S., additional, D’Cruz, David P., additional, de Berker, David, additional, DeHoratius, Danielle M., additional, Deng, Min, additional, Desai, Seemal R., additional, Devlin, Georgina, additional, DiGiovanna, John J., additional, Doctoroff, Alexander, additional, Dodiuk-Gad, Roni P., additional, Eichenfield, Dawn Z., additional, Eichenfield, Lawrence F., additional, Eisen, Drore, additional, Eke, Ure, additional, Elston, Dirk M., additional, Emanuel, Patrick O.M., additional, Enos, Clinton W., additional, Ensanyat, Shaheen H., additional, Falabella, Anna F., additional, Farberg, Aaron S., additional, Feigenbaum, Lawrence S., additional, Fernandez, Kristen Heins, additional, Fett, Nicole, additional, Finlay, Andrew Y., additional, Firoz, Bahar F., additional, Firoz, Elnaz F., additional, Fitzpatrick, James E., additional, Flischel, Amy E., additional, Foley, Kelly A., additional, Freedman, Derek, additional, Fremlin, Georgina A., additional, Fried, Richard, additional, Friedlander, Philip, additional, Friedman, Adam, additional, Forrestel, Amy K., additional, Fuchs, Brian S., additional, Gach, Joanna E., additional, Galan, Anjela, additional, Ganesh, Jaya, additional, Garg, Amit, additional, Geller, Lauren, additional, Gelmetti, Carlo M., additional, Ghazi, Elizabeth, additional, Ghunawat, Sneha, additional, Goldberg, Leonard H., additional, Goodfield, Mark J.D., additional, Gordon, Marsha L., additional, Gowda, Asha, additional, Grabell, Daniel A., additional, Grant, Matthew, additional, Grattan, Clive E.H., additional, Greaves, Malcolm W., additional, Green, Justin J., additional, Griffiths, Christopher E.M., additional, Gropper, Charles A., additional, Grossberg, Anna L., additional, Gupta, Aditya K., additional, Hadi, Ali S., additional, Hadi, Suhail M., additional, Hagans, Iris A., additional, Hairston, Bethany R., additional, Halpern, Analisa Vincent, additional, Halverstam, Caroline, additional, Harper, Natasha, additional, Harries, Matthew J., additional, Harris, John, additional, Harrison, Shannon, additional, Hatch, Michael M., additional, Heagerty, Adrian H.M., additional, Hebert, Adelaide A., additional, Helms, Stephen E., additional, Hexsel, Camile L., additional, Hexsel, Doris M., additional, Heymann, Warren R., additional, Higgins, Elisabeth M., additional, Higgins, Claire L., additional, High, Whitney A., additional, Hönigsmann, Herbert, additional, Horenstein, Marcelo G., additional, Hruza, George J., additional, Hui, Andrea, additional, Huo, Ran, additional, Ibbotson, Sally H., additional, Ibrahim, Sherrif F., additional, Ilchyshyn, Andrew, additional, Ismail, Dina, additional, Jablonska, Stefania, additional, Jacobe, Heidi T., additional, James, William D., additional, Javed, Aysha, additional, Jemec, Gregor B.E., additional, Johnston, Graham A., additional, Jones, Stephen K., additional, Junkins-Hopkins, Jacqueline M., additional, Kaffenberger, Jessica, additional, Kane, Kelly R., additional, Kanelleas, Antonios, additional, Karadağ, Ayşe Serap, additional, Karas, Laura, additional, Katugampola, Ruwani P., additional, Katz, Bruce E., additional, Kellen, Roselyn, additional, Khan, Murtaza, additional, Khorasani, Hooman, additional, Kim, Ellen J., additional, Kim, Hee J., additional, Kirby, Brian, additional, Kirby, Joslyn S., additional, Klein, Rachel S., additional, Kleydman, Kate, additional, Koch, Dimitra, additional, Kohorst, John J., additional, Koo, John Y.M., additional, Kopp, Sandra A., additional, Korman, Neil J., additional, Kovarik, Carrie, additional, Kraemer, Kenneth H., additional, Krafchik, Bernice R., additional, Krishnamurthy, Karthik, additional, Kvernebo, Knut, additional, Lam, Charlene, additional, Lambert, Peter C., additional, Langtry, James A.A., additional, Larian, Amir A., additional, Larocca, Cecilia A., additional, Lawlor, E. Frances, additional, Lawrence, Clifford M., additional, Lebwohl, Mark G., additional, Lebwohl, Oscar, additional, Lehman, Julia S., additional, Leslie, Tabi A., additional, Lessin, Stuart R., additional, Levitt, Jacob O., additional, Lewis, Fiona M., additional, Liaqat, Maryam, additional, Liu, Kristina J., additional, Loosemore, Michael P., additional, Luger, Thomas A., additional, Lupi, Omar, additional, Lushniak, Boris D., additional, Lyon, Calum C., additional, Maderal, Andrea D., additional, Mahmoud, Bassel H., additional, Majewski, Slawomir, additional, Mallett, Richard B., additional, Manders, Steven M., additional, Mann, Ranon, additional, Mansouri, Yasaman, additional, Margolis, David J., additional, Markowitz, Orit, additional, Marsland, Alexander, additional, Martin-Clavijo, Agustin, additional, Martinez, Daniela, additional, Matiz, Catalina, additional, Maurer, Marcus, additional, McKerrow, Kevin, additional, Meah, Nekma, additional, Micali, Giuseppe, additional, Micheletti, Robert G., additional, Millard, Leslie G., additional, Miller, James E., additional, Wong Millsop, Jillian W., additional, Mimouni, Daniel, additional, Mirowski, Ginat W., additional, Mirza, Sultan A., additional, Molin, Sonja, additional, Morales-Burgos, Adisbeth, additional, Morison, Warwick L., additional, Mørk, Cato, additional, Morton, Colin A., additional, Motley, Richard J., additional, Mowbray, Megan, additional, Muldoon, Eavan G., additional, Muncaster, Anna E., additional, Murakawa, George J., additional, Murase, Jenny E., additional, Murdoch, Michele E., additional, Nabatian, Adam S., additional, Nakamura, Mio, additional, Nalluri, Rajani, additional, Nawas, Zeena Y., additional, Needham, Glen R., additional, Newell, Glenn C., additional, Newton-Bishop, Julia, additional, Nguyen, Adam V., additional, Nixon, Rosemary L., additional, O’Brien, Jack C., additional, Ogden, Stephanie, additional, Olbricht, Suzanne M., additional, O’Shea, Sally Jane, additional, Owen, Cindy E., additional, Pan, Michael, additional, Pappas-Taffer, Lisa, additional, Parish, Jennifer L., additional, Parish, Lawrence Charles, additional, Payette, Michael, additional, Peck, Gary L., additional, Pena, Sandra, additional, Peranteau, Jarad, additional, Pereira, Frederick A., additional, Perkins, William, additional, Perlis, Clifford S., additional, Phelps, Robert G., additional, Phillips, Tania J., additional, Poh-Fitzpatrick, Maureen B., additional, Pomeranz, Miriam Keltz, additional, Pop, Samantha R., additional, Porcu, Pierluigi, additional, Powell, James B., additional, Prok, Lori D., additional, Pyle, Tia M., additional, Qazaz, Surod, additional, Rajkomar, Vikram, additional, Rashid, Rabia S., additional, Rashighi, Mehdi, additional, Ratnavel, Ravi, additional, Regula, Christie G., additional, Renzi, Michael, additional, Revuz, Jean, additional, Reynolds, Rachel V., additional, Richard, Elisabeth, additional, Richard, Gabriele, additional, Rigel, Darrell S., additional, Robles, Wanda Sonia, additional, Rogge, Megan, additional, Rook, Alain H., additional, Manning, Jamie R., additional, Rosen, Ted, additional, Rosenbach, Misha, additional, Rosenfeld, David, additional, Rowland Payne, Christopher, additional, Rubin, Adam I., additional, Rubin, Courtney, additional, Rustin, Malcolm H.A., additional, Ruzicka, Thomas, additional, Samimi, Sara, additional, Schachner, Lawrence A., additional, Scheinfeld, Noah, additional, Schlosser, Bethanee J., additional, Schnur, Rhonda E., additional, Schwartz, Robert A., additional, Scorer, Matthew J., additional, Selkin, Bryan A., additional, Seymour, Jamie, additional, Shaver, Christine M., additional, Shea, Christopher R., additional, Shear, Neil H., additional, Shim, Tang Ngee, additional, Shimizu, Hiroshi, additional, Siegel, Julia, additional, Singer, Elisha, additional, Skelsey, Maral Kibarian, additional, Sladden, Chris, additional, Sladden, Michael, additional, Smith, Janellen, additional, Smucker, Joanne E., additional, Somani, Najwa, additional, Sommer, Lacy L., additional, Sommerlad, Mary, additional, Soon, Christine, additional, Sopkovich, Jennifer A., additional, Soter, Nicholas A., additional, Spencer, James M., additional, Staughton, Richard C.D., additional, Sterling, Jane C., additional, Sunderkötter, Cord, additional, Taibjee, Saleem M., additional, Tamura, Deborah, additional, Tan, Eunice, additional, Tang, William Y-M., additional, Taylor, Lynsey, additional, Thiers, Bruce H., additional, Thomas, Lucy J., additional, Thornton, Cody R., additional, Tobin, Anne-Marie, additional, Torgerson, Rochelle R., additional, Tosti, Antonella, additional, Tsatsou, Fragkiski, additional, Tsuji-Abe, Yukiko, additional, Tucker, William F.G., additional, Tyring, Stephen K., additional, Udkoff, Jeremy, additional, Unger, Robin H., additional, Unger, Walter P., additional, Utz, Sarah, additional, Valbuena, Martha C., additional, van de Kerkhof, Peter, additional, Van Voorhees, Abby S., additional, Vangipuram, Ramya, additional, Veitch, David, additional, Venning, Vanessa, additional, Versteeg, Sarah G., additional, Viera, Martha, additional, Vittorio, Carmela C., additional, Vleugels, Ruth Ann, additional, Wali, Gorav N., additional, Wallengren, Joanna, additional, Wan, Joy, additional, Wanat, Karolyn A., additional, Weichert, Gabriele, additional, Weidmann, Anja K., additional, Weinberg, Jeffrey M., additional, Werth, Victoria P., additional, White, Lucile E., additional, Wiener, Adam H., additional, Wilkin, Jonathan K., additional, Wilkin, Nathaniel K., additional, Williams, Jason, additional, Wilson, Niall, additional, Wiss, Karen, additional, Witkowski, Joseph A., additional, Wiznia, Lauren E., additional, Wong, Henry K., additional, Wong, Junie Li Chun, additional, Wright, Andrew L., additional, Wriston, Cooper C., additional, Wu, Benedict C., additional, Wulkan, Adam, additional, Zaenglein, Andrea L., additional, Zaki, Irshad, additional, Zeichner, Joshua A., additional, Zhu, Tian Hao, additional, Zone, John J., additional, Zouboulis, Christos C., additional, and Zuberbeir, Torstein, additional

Published
2018
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26. A satellite chronology of plumes from the April 2021 eruption of La Soufrière, St Vincent.

Author

Taylor, Isabelle A., Grainger, Roy G., Prata, Andrew T., Proud, Simon R., Mather, Tamsin A., and Pyle, David M.

Subjects
VOLCANIC eruptions, HIGH resolution imaging, BRIGHTNESS temperature, STRATOSPHERE, COLUMNS, TIME series analysis
Abstract

Satellite instruments play a valuable role in detecting, monitoring and characterising emissions of ash and gas into the atmosphere during volcanic eruptions. This study uses two satellite instruments, the Infrared Atmospheric Sounding Interferometer (IASI) and the Advanced Baseline Imager (ABI), to examine the plumes of ash and sulfur dioxide (SO 2) from the April 2021 eruption of La Soufrière, St Vincent. The frequent ABI data have been used to construct a 14 d chronology of a series of explosive events at La Soufrière, which is then complemented by measurements of SO 2 from IASI, which is able to track the plume as it is transported around the globe. A minimum of 35 eruptive events were identified using true, false and brightness temperature difference maps produced with the ABI data. The high temporal resolution images were used to identify the approximate start and end times, as well as the duration and characteristics of each event. From this analysis, four distinct phases within the 14 d eruption have been defined, each consisting of multiple explosive events with similar characteristics: (1) an initial explosive event, (2) a sustained event lasting over 9 h, (3) a pulsatory phase with 25 explosive events in a 65.3 h period and (4) a waning sequence of explosive events. It is likely that the multiple explosive events during the April 2021 eruption contributed to the highly complex plume structure that can be seen in the IASI measurements of the SO 2 column amounts and heights. The bulk of the SO 2 from the first three phases of the eruption was transported eastwards, which based on the wind direction at the volcano implies that the SO 2 was largely in the upper troposphere. Some of the SO 2 was carried to the south and west of the volcano, suggesting a smaller emission of the gas into the stratosphere, there being a shift in wind direction around the height of the tropopause. The retrieved SO 2 heights show that the plume had multiple layers but was largely concentrated between 13 and 19 km, with the majority of the SO 2 being located in the upper troposphere and around the height of the tropopause, with some emission into the stratosphere. An average e -folding time of 6.07±4.74 d was computed based on the IASI SO 2 results: similar to other tropical eruptions of this magnitude and height. The SO 2 was trackable for several weeks after the eruption and is shown to have circulated the globe, with parts of it reaching as far as 45 ∘ S and 45 ∘ N. Using the IASI SO 2 measurements, a time series of the total SO 2 mass loading was produced, with this peaking on 13 April (descending orbits) at 0.31±0.09 Tg. Converting these mass values to a temporally varying SO 2 flux demonstrated that the greatest emission occurred on 10 April with that measurement incorporating SO 2 from the second phase of the eruption (sustained emission) and the beginning of the pulsatory phase. The SO 2 flux is then shown to fall during the later stages of the eruption: suggesting a reduction in eruptive energy, something also reflected in ash height estimates obtained with the ABI instrument. A total SO 2 emission of 0.63±0.5 Tg of SO 2 has been derived, although due to limitations associated with the retrieval, particularly in the first few days after the eruption began, this, the retrieved column amounts and the total SO 2 mass on each day should be considered minimum estimates. There are a number of similarities between the 1979 and 2021 eruptions at La Soufrière, with both eruptions consisting of a series of explosive events with varied heights and including some emission into the stratosphere. These similarities highlight the importance of in-depth investigations into eruptions and the valuable contribution of satellite data for this purpose; as these studies aid in learning about a volcano's behaviour, which may allow for better preparation for future eruptive activity. [ABSTRACT FROM AUTHOR]

Published
2023
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38. The Source Physics Experiment (SPE) Science Plan (Version 2.4c)

Author

Snelson, Catherine M., primary, Bradley, Christopher R., additional, Walter, William R., additional, Antoun, Tarabay H., additional, Abbott, Robert, additional, Jones, Kyle, additional, Chipman, Veraun D., additional, Montoya, Lloyd, additional, Brunish, Wendee M., additional, Coblentz, David, additional, Hawkins, Ward L., additional, Kelley, Richard E., additional, Knight, Earl E., additional, Larmat, Carene, additional, Miller, Elizabeth D., additional, Patton, Howard J., additional, Rougier, Esteban, additional, Rowe, Charlotte A., additional, Sandoval, Thomas D., additional, Schultz-Fellenz, Emily S., additional, Steedman, David W., additional, Sussman, Aviva J., additional, Whitaker, Rodney W., additional, Wilson, Jennifer E., additional, Yang, David, additional, Burkhard, Norm, additional, Ezzedine, Souheil M., additional, Ford, Sean R., additional, Glenn, Lewis A., additional, Hauk, Teresa F., additional, Matzel, Eric M., additional, Mellors, Robert J., additional, Pasyanos, Michael E., additional, Pitarka, Arben, additional, Pyle, Moira M., additional, Rodgers, Arthur J., additional, Vorobiev, Oleg Y., additional, Wagoner, Jeff, additional, Vigil, Steve, additional, Preston, Leiph, additional, Aldridge, Dave, additional, and Townsend, Margaret, additional

Published
2019
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40. Detecting the next volcanic eruption: satellite monitoring and networks of instruments on the ground can detect, but not predict, volcanic eruptions

Author

Pyle, David M.

Subjects
Seismology -- Methods, Volcanoes -- United States -- Natural history -- Observations, Anthropology/archeology/folklore, Biological sciences, Earth sciences, Science and technology, Zoology and wildlife conservation
Abstract

The past 150 years have seen a dramatic change in our ability to measure activity at volcanoes, whether they are dormant, or in eruption. New instruments have been designed that [...]

Published
2017

41. Geochronology and glass geochemistry of major Pleistocene eruptions in the Main Ethiopian Rift: Towards a regional tephrostratigraphy

Author

Vidal, Céline M., primary, Fontijn, Karen, additional, Lane, Christine S., additional, Asrat, Asfawossen, additional, Barfod, Dan, additional, Tomlinson, Emma L., additional, Piermattei, Alma, additional, Hutchison, William, additional, Tadesse, Amdemichael Zafu, additional, Yirgu, Gezahegn, additional, Deino, Alan, additional, Moussallam, Yves, additional, Mohr, Paul, additional, Williams, Frances, additional, Mather, Tamsin A., additional, Pyle, David M., additional, and Oppenheimer, Clive, additional

Published
2022
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47. Geochronology and glass geochemistry of major pleistocene eruptions in the Main Ethiopian Rift: Towards a regional tephrostratigraphy

Author

Vidal, Céline M., Fontijn, Karen, Lane, Christine S, Asrat, Asfawossen, Barfod, Dan, Tomlinson, Emma L, Piermattei, Alma, Hutchison, William, Tadesse, Amdemichael, Yirgu, Gezahegn, Deino, Alan L, Moussallam, Yves, Mohr, Paul, Williams, Frances, Mather, Tamsin A., Pyle, David M, Oppenheimer, Clive, Vidal, Céline M., Fontijn, Karen, Lane, Christine S, Asrat, Asfawossen, Barfod, Dan, Tomlinson, Emma L, Piermattei, Alma, Hutchison, William, Tadesse, Amdemichael, Yirgu, Gezahegn, Deino, Alan L, Moussallam, Yves, Mohr, Paul, Williams, Frances, Mather, Tamsin A., Pyle, David M, and Oppenheimer, Clive

Abstract

The Main Ethiopian Rift (MER) is renowned as a focus of investigations into human origins. It is also the site of many large volcanic calderas, whose eruptions have spanned the timeframe of speciation, cultural innovation, and dispersal of our species. Yet, despite their significance for dating human fossils and cultural materials, the timing and geochemical signatures of some of the largest eruptions have remained poorly constrained at best. Here, through a programme of field surveys, geochemical analysis and 40Ar/39Ar dating, we report the ages of MER ignimbrites and link them to widespread tephra layers found in sequences of archaeological and paleoenvironmental significance. We date major eruptions of Fentale (76 ± 18 ka), Shala (ca. 145–155 ka), Kone (184 ± 42 ka and ca. 200 ± 12 ka) and Gedemsa (251 ± 47 ka) volcanoes, and correlate a suite of regionally important tephra horizons. Geochemical analysis highlights the predominantly peralkaline rhyolitic melt compositions (7.5–12 wt% Na2O + K2O, 70–76 wt% SiO2) across the central MER and remarkable similarity in incompatible trace element ratios, limiting the correlation of deposits via glass composition alone. However, by integrating stratigraphic and geochronological evidence from proximal deposits, lake sediment cores and distal outcrops at archaeological sites, we have traced ash layers associated with the ca. 177 ka Corbetti, ca. 145–155 ka Shala and ca. 108 ka Bora-Baricha-Tullu-Moye eruptions across southern Ethiopia. In addition to strengthening the tephrochronological framework that supports paleoenvironmental and archaeological work in the region, our findings have wider implications for evaluating the hypothesis of a middle Pleistocene ‘ignimbrite flare-up’ in the MER, and for evaluating the impacts of these great eruptions on landscapes, hydrology, and human ecology., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2022

48. Stratigraphy and eruptive history of Corbetti Caldera in the Main Ethiopian Rift

Author

Colby, David, Pyle, David M, Fontijn, Karen, Mather, Tamsin A., Melaku, Abate A., Mengesha, Million, Yirgu, Gezahegn, Colby, David, Pyle, David M, Fontijn, Karen, Mather, Tamsin A., Melaku, Abate A., Mengesha, Million, and Yirgu, Gezahegn

Abstract

The East African Rift (EAR) hosts the highest density of peralkaline volcanoes of any region globally, making it an ideal location to study the subaerial and magmatic processes of peralkaline volcanism. Corbetti Caldera is one such peralkaline centre found within the southern part of the Main Ethiopian Rift (MER), a segment of the EAR. Corbetti is actively deforming and has previously undergone large-scale Plinian eruptions. However, our broader understanding of Corbetti's evolution is limited. Here we present a detailed study of the pre-, syn-and post-caldera eruptive deposits and compile them into a composite stratigraphy of the volcanic sequence. We find evidence for multiple previously undocumented large-scale eruptions, including the deposition of two pre-caldera lithic lag breccias, and we identify three additional post-caldera obsidian lavas. We constrain the age of a young Tuff Cone, Biftu, which sits outside the caldera walls, to <7375 ± 54 cal BP through 14C dating of shells within an associated PDC deposit. The Wendo Koshe Cone, the most recent cone within the complex, is interpreted as the remains of two cones that opened in close proximity to each other and formed the vents for two pyroclastic eruptions: Bedded Pumice and Wendo Koshe Younger Pumice (WKYP). There is abundant evidence for the occurrence of pyroclastic density currents (PDC) within the caldera, usually associated with pumice cone-forming eruptions. These flow deposits rarely extend beyond the caldera walls. From our compiled stratigraphy, we estimate a recurrence rate of one eruption per 300–400 years over the last 2.3 ky. These findings are especially significant as Corbetti is earmarked for potential geothermal exploration, and an understanding of eruptive frequency and style provides vital context to assess the potential hazards associated with this future infrastructure., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2022

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