Coombs, Michelle
Michelle has been a Research Geologist for USGS-AVO in Anchorage since 2004. Her work includes research on a wide variety of topics in geology, petrology, and geochemistry, as well as geologic mapping and hazards assessment. Recent and current research interests include (1) timing and generation of explosive silicic eruptions at Alaskan volcanoes, especially Augustine and Hayes; (2) refined edifice mapping and eruptive history of Akutan, Spurr, and Redoubt volcanoes; and (3) combining petrologic study with detailed eruption chronologies to elucidate processes of magma generation and eruption triggering at dome-forming volcanoes such as Redoubt and Augustine. From March 2016 to May 2023, Michelle was the Scientist-in-Charge for AVO. Prior to 2004, she worked for the USGS in Menlo Park, CA, where her research focused on the geochemistry, petrology, and submarine geology of Hawaiian volcanoes.
Website: http://profile.usgs.gov/mcoombs
Discipline(s): Geochemistry, Geochronology, Geology, Petrology, Tephra
References:
Mount Spurr volcano, 2025
Wallace, K.L., Waythomas, C.F., Coombs, M.L.,and Nastan, A.M., 2025, Mount Spurr Volcano: Alaska Division of Geological & Geophysical Surveys Information Circular 98, 2 p. https://doi.org/10.14509/31518
full-text PDF 1108 kb Bulk compositions of western Aleutians tephras and lavas collected during leg 3 of the NSF GeoPRISMS shared platform for Aleutians research, Version 1.0, 2024
Andrys, J. L., Coombs, M. L., Cottrell, E., Kelley, K. A., Waters, L. E., and Jicha, B., 2024, Bulk compositions of western Aleutians tephras and lavas collected during leg 3 of the NSF GeoPRISMS shared platform for Aleutians research, Version 1.0: Interdisciplinary Earth Data Alliance (IEDA). https://doi.org/10.60520/IEDA/113465.From field station to forecast: managing data at the Alaska Volcano Observatory, 2024
Coombs, M.L., Cameron, C.E., Dietterich, H.R., Boyce, E.S., Wech, A.G., Grapenthin, R., Wallace, K.L., Parker, T., Lopez, T., Crass, S., Fee, D., Haney, M.M., Ketner, D., Loewen, M.W., Lyons, J.J., Nakai, J.S., Power, J.A., Botnick, S., Brewster, I., Enders, M.L., Harmon, D., Kelly, P.J., and Randall, M., 2024, From field station to forecast: managing data at the Alaska Volcano Observatory: Bulletin of Volcanology v. 86, 79. https://doi.org/10.1007/s00445-024-01766-0Tephra samples and analyses from Cook Inlet source volcanoes and Anchor Point, Alaska, 2024
Loewen, M.W., Wallace, Kristi, Coombs, M.L., and Mulliken, K.M., 2023, Tephra samples and analyses from Cook Inlet source volcanoes and Anchor Point, Alaska: Alaska Division of Geological & Geophysical Surveys Raw Data File 2023-25, 4 p. https://doi.org/10.14509/31090Probabilistic source classification of large tephra producing eruptions using supervised machine learning - an example from the Alaska-Aleutian Arc, 2023
Lubbers, J., Loewen, M., Wallace, K., Coombs, M., and Addison, J., 2023, Probabilistic source classification of large tephra producing eruptions using supervised machine learning - an example from the Alaska-Aleutian Arc: Geochemistry, Geophysics, Geosystems v. 24, no. 11, e2023GC011037. https://doi.org/10.1029/2023GC011037.Eruption of compositionally heterogeneous andesites from a complex storage region during the 2006 eruption of Augustine Volcano, 2021
Benage, M.C., Wright, H.M.N., and Coombs, M.L., 2021, Eruption of compositionally heterogeneous andesites from a complex storage region during the 2006 eruption of Augustine Volcano: Bulletin of Volcanology, v. 83, n. 17, 23 p., doi:10.1007/s00445-020-01431-2.Generation of calc-alkaline magmas during crystallization at high oxygen fugacity: an experimental and petrologic study of tephras from Buldir Volcano, western Aleutian arc, Alaska, USA, 2021
Waters, L.E., Cottrell, Elizabeth, Coombs, M.L., and Kelley, K.A., 2021, Generation of calc-alkaline magmas during crystallization at high oxygen fugacity: an experimental and petrologic study of tephras from Buldir Volcano, western Aleutian arc, Alaska, USA: Journal of Petrology, p. 1-36, doi:10.1093/petrology/egaa104.Phase equilibrium of a high SiO2 andesite at fO2=RRO - Implications for Augustine Volcano and other high fO2 arc andesites, 2020
De Angelis, S.H., Larsen, J.F., Coombs, M.L., Utley, J.E.P., and Dunn, Andrew, 2020, Phase equilibrium of a high SiO2 andesite at fO2=RRO - Implications for Augustine Volcano and other high fO2 arc andesites: Contributions to Mineralogy and Petrology, v. 175, no. 24, 20 p., https://doi.org/10.1007/s00410-020-1663-6.Phase equlibrium of a high-SiO2 andesite at fO2=RRO: implications for Augustine Volcano and other high-fO2 arc andesites, 2020
De Angelis, S.H., Larsen, J.F., Coombs, M.L., Utley, J.E.P., and Dunn, Andrew, 2020, Phase equlibrium of a high-SiO2 andesite at fO2=RRO: implications for Augustine Volcano and other high-fO2 arc andesites: Contributions to Mineralogy and Petrology, v. 175, n. 24, 21 p., doi: https://doi.org/10.1007/s00410-020-1663-6.The eruptive history, magmatic evolution, and influence of glacial ice at long-lived Akutan volcano, eastern Aleutian Islands, Alaska, 2020
Coombs, M.L., and Jicha, B.R., 2020, The eruptive history, magmatic evolution, and influence of glacial ice at long-lived Akutan volcano, eastern Aleutian Islands, Alaska: GSA Bulletin, 29 p., https://doi.org/10.1130/B35667.1.Overview, chronology, and impacts of the 2016-2017 eruption of Bogoslof volcano, Alaska, 2019
Coombs, Michelle, Wallace, Kristi, Cameron, Cheryl, Lyons, John, Wech, Aaron, Angeli, Kim, and Cervelli, Peter, 2019, Overview, chronology, and impacts of the 2016-2017 eruption of Bogoslof volcano, Alaska: Bulletin of Volcanology, v, 81, n. 62, doi:10.1007/s00445-019-1322-9.Petrology of the 2016-2017 eruption of Bogoslof Island, Alaska, 2019
Loewen, M.L., Izbekov, Pavel, Moshrefzadeh, Jamshid, Coombs, Michelle, Larsen, Jessica, Graham, Nathan, Harbin, Michelle, Waythomas, Christopher, and Wallace, Kristi, 2019, Petrology of the 2016-2017 eruption of Bogoslof Island, Alaska: Bulletin of Volcanology v. 81, n. 72, 20 p., doi:10.1007/s00445-019-1333-6.Postglacial eruptive history and geochemistry of Semisopochnoi volcano, western Aleutian Islands, Alaska, 2018
Coombs, M.L., Larsen, J.F., and Neal, C.A., 2018, Postglacial eruptive history and geochemistry of Semisopochnoi volcano, western Aleutian Islands, Alaska: U.S. Geological Survey Scientific Investigations Report 2017-5150, 32 p., https://doi.org/10.3133/sir20175150.Short-term forecasting and detection of explosions during the 2016-2017 eruption of Bogoslof Volcano, Alaska, 2018
Coombs, M.L., Wech, A.G., Haney, M.M., Lyons, J.J., Schneider, D.J., Schwaiger, H.F., Wallace, K.L., Fee, David, Freymueller, J.T., Schaefer, J.R., and Tepp, Gabrielle, 2018, Short-term forecasting and detection of explosions during the 2016-2017 eruption of Bogoslof Volcano, Alaska: Frontiers in Earth Science, v. 6, article 122, doi: 10.3389/feart.2018.00122 .Aleutian arc geothermal fluids: chemical analyses of waters and gases, 2015
Evans, W.C., Bergfeld, D., Neal, C.A., McGimsey, R.G., Werner, C.A., Waythomas, C.F., Lewicki, J.L., Lopez, T., Mangan, M.T., Miller, T.P., Diefenbach, A., Schaefer, J., Coombs, M.L., Wang, B., Nicolaysen, K., Izbekov, P., Maharrey, Z., Huebner, M., Hunt, A.G., Fitzpatrick, J., and Freeburg, G., 2015, Aleutian Arc geothermal fluids: chemical analyses of waters and gases: U.S. Geological Survey Data release, http://dx.doi.org/10.5066/F74X55VB
data tables (.xlsx) 101 KB Amphibole reaction rims as a record of pre-eruptive magmatic heating: an experimental approach, 2015
De Angelis, S.H., Larsen, J., Coombs, M., Dunn, A., and Hayden, L., 2015, Amphibole reaction rims as a record of pre-eruptive magmatic heating: an experimental approach: Earth and Planetary Science Letters, v. 426, p. 235-245, doi:10.1016/j.epsl.2015.06.051Cogenetic late Pleistocene rhyolite and cumulate diorites from Augustine Volcano revealed by SIMS 238U-230Th dating of zircon, and implications for silicic magma generation by extraction from mush, 2014
Coombs, M.L., and Vazquez, J.A., 2014, Cogenetic late Pleistocene rhyolite and cumulate diorites from Augustine Volcano revealed by SIMS 238U-230Th dating of zircon, and implications for silicic magma generation by extraction from mush: Geochemistry, Geophysics, Geosystems, v. 15, 20 p., doi:10.1002/2014GC005589Significance of a near-source tephra-stratigraphic sequence to the eruptive history of Hayes Volcano, south-central Alaska, 2014
Wallace, K.L., Coombs, M.L., Hayden, L.A., and Waythomas, C.F., 2014, Significance of a near-source tephra-stratigraphic sequence to the eruptive history of Hayes Volcano, south-central Alaska: U.S. Geological Survey Scientific Investigations Report 2014-5133, 32 p., available online at: http://pubs.usgs.gov/sir/2014/5133/
full-text PDF 864 KB
excel files 1 MB Andesites of the 2009 eruption of Redoubt Volcano, Alaska, 2013
Coombs, M.L., Sisson, T.W., Bleick, H.A., Henton, S.M., Nye, C.J., Payne, A.L., Cameron, C.E., Larsen, J.F., Wallace, K.L., and Bull, K.F., 2013, Andesites of the 2009 eruption of Redoubt Volcano, Alaska: Journal of Volcanology and Geothermal Research, v. 259, p. 349-372, doi:10.1016/j.jvolgeores.2012.01.002Character, mass, distribution, and origin of tephra-fall deposits from the 2009 eruption of Redoubt Volcano, Alaska - Highlighting the significance of particle aggregation, 2013
Wallace, K.L., Schaefer, J.R., and Coombs, M.L., 2013, Character, mass, distribution, and origin of tephra-fall deposits from the 2009 eruption of Redoubt Volcano, Alaska - Highlighting the significance of particle aggregation: Journal of Volcanology and Geothermal Research, v. 259, p. 145-169, doi:10.1016/j.jvolgeores.2012.09.015
full-text pdf 6.3 MB High-resolution satellite and airborne thermal infrared imaging of precursory unrest and 2009 eruption at Redoubt Volcano, Alaska, 2013
Wessels, R.L., Vaughan, R.G., Patrick, M.R., and Coombs, M.L., 2013, High-resolution satellite and airborne thermal infrared imaging of precursory unrest and 2009 eruption at Redoubt Volcano, Alaska: Journal of Volcanology and Geothermal Research, v. 259, p. 248-269, doi:10.1016/j.jvolgeores.2012.04.014
full-text pdf 6.55 MB Pre-eruptive magmatic conditions at Augustine Volcano, Alaska, 2006: evidence from amphibole geochemistry and textures, 2013
De Angelis, S.H., Larsen, Jessica, and Coombs, Michelle, 2013, Pre-eruptive magmatic conditions at Augustine Volcano, Alaska, 2006: evidence from amphibole geochemistry and textures: Journal of Petrology, v. 54, n. 9, p. 1939-1961, doi:10.1093/petrology/egt037Volcano-ice interactions precursory to the 2009 eruption of Redoubt Volcano, Alaska, 2013
Bleick, H.A., Coombs, M.L., Cervelli, P.F., Bull, K.F., and Wessels, R.L., 2013, Volcano-ice interactions precursory to the 2009 eruption of Redoubt Volcano, Alaska: Journal of Volcanology and Geothermal Research, v. 259, p. 373-388, doi:10.1016/j.jvolgeores.2012.10.008
full-text pdf 4.6 MB