Michelle L. Coombs, Ph.D.
Michelle Coombs is a Research Geologist with the U.S. Geological Survey Volcanic Science Center. She served as Scientist-in-Charge of the Alaska Volcano Observatory from 2016-2023. In this position, Dr. Coombs leads eruption responses, oversees expansion and modernization of volcano monitoring techniques, and guides applied and fundamental research on a host of problems related to volcanology.
Professional Experience
2016–2023: Scientist-in-Charge, Alaska Volcano Observatory, Volcano Science Center, U.S. Geological Survey, Anchorage, AK
2004–Present: Research Geologist, Alaska Volcano Observatory
2001–2004: Research Geologist, Volcano Hazards Team, U.S. Geological Survey, Menlo Park CA
OTHER PROFESSIONAL ACTIVITIES
Affiliate faculty, University of Alaska Fairbanks
CONVERSE Steering Committee member, 2020–present
Member of AGU student awards committee, 2011–2015
Associate Editor, Bulletin of Volcanology, 2013–2016
Editorial board, Journal of Volcanology and Geothermal Research, 2007–2018
Co-editor for 28-chapter USGS Professional Paper 1769, The 2006 eruption of Augustine Volcano, Alaska, 2010
Co-editor for Journal of Volcanology and Geothermal Research special issue on Growth and collapse of Hawaiian volcanoes, 2006
Education and Certifications
Williams College, BA Geology, 1994
University of Alaska Fairbanks, PhD Geology, 2001
Affiliations and Memberships*
American Geophysical Union, 1996–present
Geological Society of America, 2001–present (elected Fellow in 2015)
International Assoc. of Volcanology and Chemistry of the Earth’s Interior, 1999–present
Science and Products
Submarine sliver in North Kona: A window into the early magmatic and growth history of Hualalai Volcano, Hawaii
Piggyback tectonics: Long-term growth of Kilauea on the south flank of Mauna Loa
Growth history of Kilauea inferred from volatile concentrations in submarine-collected basalts
Major-element, sulfur, and chlorine compositions of glasses from the submarine flank of Kilauea Volcano, Hawaii, Collected During 1998-2002 Japan Marine Science and Technology Center (JAMSTEC) Cruises
Ultra-high chlorine in submarine Kı̄lauea glasses: Evidence for direct assimilation of brine by magma
Reaction rim growth on olivine in silicic melts: Implications for magma mixing
Growth and collapse of Waianae volcano, Hawaii, as revealed by exploration of its submarine flanks
Renewed unrest at Mount Spurr Volcano, Alaska
Shallow-storage conditions for the rhyolite of the 1912 eruption at Novarupta, Alaska
Magma storage and mixing conditions for the 1953-1974 eruption of Southwest Trident volcano, Katmai National Park, Alaska
Science and Products
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Filter Total Items: 70
Submarine sliver in North Kona: A window into the early magmatic and growth history of Hualalai Volcano, Hawaii
Two manned submersible dives examined the Hualalai Northwest rift zone and an elongate ridge cresting at 3900 mbsl during a 2002 JAMSTEC cruise. The rift zone flank at dive site S690 (water depth 3412–2104 m) is draped by elongated and truncated pillow lavas. These olivine-rich tholeiitic lavas are compositionally indistinguishable from those examined further south along the bench, except that theAuthorsJulia E. Hammer, Michelle L. Coombs, Patrick J. Shamberger, Jun-Ichi KimuraPiggyback tectonics: Long-term growth of Kilauea on the south flank of Mauna Loa
Compositional and age data from offshore pillow lavas and volcaniclastic sediments, along with on-land geologic, seismic, and deformation data, provide broad perspectives on the early growth of Kilauea Volcano and the long-term geometric evolution of its rift zones. Sulfur-rich glass rinds on pillow lavas and volcaniclastic sediments derived from them document early underwater growth of a large coAuthorsPeter W. Lipman, Thomas W. Sisson, Michelle L. Coombs, Andrew T. Calvert, Jun-Ichi KimuraGrowth history of Kilauea inferred from volatile concentrations in submarine-collected basalts
Major-element and volatile (H2O, CO2, S) compositions of glasses from the submarine flanks of Kilauea Volcano record its growth from pre-shield into tholeiite shield-stage. Pillow lavas of mildly alkalic basalt at 2600–1900 mbsl on the upper slope of the south flank are an intermediate link between deeper alkalic volcaniclastics and the modern tholeiite shield. Lava clast glasses from the west flaAuthorsMichelle L. Coombs, Thomas W. Sisson, Peter W. LipmanMajor-element, sulfur, and chlorine compositions of glasses from the submarine flank of Kilauea Volcano, Hawaii, Collected During 1998-2002 Japan Marine Science and Technology Center (JAMSTEC) Cruises
No abstract available.AuthorsMichelle L. Coombs, Thomas W. Sisson, Peter W. LipmanUltra-high chlorine in submarine Kı̄lauea glasses: Evidence for direct assimilation of brine by magma
Basaltic glass grains from the submarine south flank of Kı̄lauea, Hawai′i, have Cl concentrations of 0.01–1.68 wt%, the latter being the highest Cl content yet recorded for a Hawaiian glass. The high-Cl glass grains are products of brine assimilation by tholeiite magma. The glasses are grains in a sandstone clast from bedded breccias draping the southwestern margin of Kı̄lauea’s submarine midslopeAuthorsMichelle L. Coombs, Thomas W. Sisson, Jun-Ichi KimuraReaction rim growth on olivine in silicic melts: Implications for magma mixing
Finely crystalline amphibole or pyroxene rims that form during reaction between silicic host melt and cognate olivine xenocrysts, newly introduced during magma mixing events, can provide information about the timing between mixing and volcanic eruptions. We investigated rim growth experimentally by placing forsteritic olivine in rhyolitic and rhyodacitic melts for times between 25 and 622 h at 50AuthorsMichelle L. Coombs, James E. GardnerGrowth and collapse of Waianae volcano, Hawaii, as revealed by exploration of its submarine flanks
Wai‘anae Volcano comprises the western half of O‘ahu Island, but until recently little was known about the submarine portion of this volcano. Seven new submersible dives, conducted in 2001 and 2002, and multibeam bathymetry offshore of Wai‘anae provide evidence pertaining to the overall growth of the volcano's edifice as well as the timing of collapses that formed the Wai‘anae slump complex. A proAuthorsMichelle L. Coombs, David A. Clague, Gregory F. Moore, Brian L. CousensRenewed unrest at Mount Spurr Volcano, Alaska
The Alaska Volcano Observatory (AVO),a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys, has detected unrest at Mount Spurr volcano, located about 125 km west of Anchorage, Alaska, at the northeast end of the Aleutian volcanic arc.This activity consists of increased seismicityAuthorsJohn A. PowerShallow-storage conditions for the rhyolite of the 1912 eruption at Novarupta, Alaska
Recent studies have proposed contrasting models for the plumbing system that fed the 1912 eruption of Novarupta, Alaska. Here, we investigate the conditions under which the rhyolitic part of the erupted magma last resided in the crust prior to eruption. Geothermometry suggests that the rhyolite was held at ∼800-850 °C, and analyses of melt inclusions suggest that it was fluid saturated and containAuthorsMichelle L. Coombs, James E. GardnerMagma storage and mixing conditions for the 1953-1974 eruption of Southwest Trident volcano, Katmai National Park, Alaska
Between 1953 and 1974, approximately 0.5 km3 of andesite and dacite erupted from a new vent on the southwest flank of Trident volcano in Katmai National Park, Alaska, forming an edifice now known as Southwest (or New) Trident. Field, analytical, and experimental evidence shows that the eruption commenced soon after mixing of dacite and andesite magmas at shallow crustal levels. Four lava flows (58AuthorsMichelle L. Coombs, John C. Eichelberger, Malcom J. Rutherford - News
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government