I am currently a Research Geologist at the USGS California Volcano Observatory (CalVO) and fundamentally a field geologist who maps Cascade volcanoes and interprets their eruptive history, geochemistry and petrology.
My primary interests are in using mineralogy, crystal chemistry and rock textures to determine the origin and evolution of magmas erupting at Cascade volcanoes. I am currently the USGS geologist who most versed in geology of the Lassen Volcanic Center and southernmost Cascades volcanoes and the geology of Mount St. Helens. I interface with managers and staff at Lassen Volcanic National Park and Mount St. Helens National Volcanic Monument on geologic and interpretation issues in those parks. I entered the USGS as a student field assistant in 1975 and have been employed there ever since.
I am currently in the final stages of producing a geologic map of Mount St. Helens. The field work is complete and I am writing the materials that will accompany the map. My goal is to understand the complex eruptive history of Mount St. Helens as thoroughly as possible using stratigraphy and geochronology. I and colleagues have added considerable detail to the geologic history framework produced by earlier USGS geologists.
My work at Lassen is at a mature stage. The geologic map of the Lassen Volcanic Center and vicinity describes the geology and eruptive history of the Lassen Volcanic Center and the many smaller volcanoes that surround it. The basic geologic work at Lassen has been used to provide a framework for interpretation of the hydrothermal system and as basis for volcano hazards assessment of the region. A variety of topical studies in collaboration with colleagues include geochronology, geochemistry, isotope geology, petrology, mineral chemistry, physical volcanology, geophysics, tectonics and hydrothermal systems. Some of the geologic processes described at Lassen have guided work at other Cascades volcanoes and the arc as a whole.
Professional Experience
Former associate editor Bulletin of Volcanology
Education and Certifications
Ph.D. University of California-Santa Cruz, 1993
M.S. California State California-San Jose, 1983
B.S. University of California-Santa Cruz, 1976
Affiliations and Memberships*
Geological Society of America
American Geophysical Union
Honors and Awards
Geological Society of America Fellow
Science and Products
Dataset Establishing Temporal Duration of Two Shield Volcanoes in Northern California
Hazard zone boundaries for the volcano hazards assessment for the Lassen region, Northern California
Database for the Geologic Map of the Lassen Peak, Chaos Crags, and Upper Hat Creek Area, California
Geologic map of Lassen Volcanic National Park and vicinity, California
Geologic Map of Lassen Volcanic National Park and Vicinity, California
Geologic map of the Lassen Peak, Chaos Crags, and Upper Hat Creek area, California
lawilátɬa—Mount St. Helens—Land in transformation
Development of a volcanic risk management system at Mount St. Helens—1980 to present
Paleomagnetically defined brief lifespans for two large shield volcanoes in the Cascades Arc
A multidisciplinary investigation into the eruptive style, processes, and duration of a Cascades back-arc tholeiitic basalt: A case study of the Brushy Butte flow field, northern California, United States
Simultaneous Middle Pleistocene eruption of three widespread tholeiitic basalts in northern California (USA): Insights into crustal magma transport in an actively extending back arc
Ten ways Mount St. Helens changed our world—The enduring legacy of the 1980 eruption
Field trip guide to Mount St. Helens, Washington—Recent and ancient volcaniclastic processes and deposits
Eruption age and duration of the ~9 km3 Burney Mountain dacite dome complex, northern California
Temporal relationship between the Lassen Volcanic Center and mafic regional volcanism
Understanding melt evolution and eruption dynamics of the 1666 C.E. eruption of Cinder Cone, Lassen Volcanic National Park, California: Insights from olivine-hosted melt inclusions
Pleistocene hydrothermal activity on Brokeoff volcano and in the Maidu volcanic center, Lassen Peak area, northeast California: Evolution of magmatic-hydrothermal systems on stratovolcanoes
A re-examination of the three most prominent Holocene tephra deposits in western Canada: Bridge River, Mount St. Helens Yn and Mazama
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Data
Dataset Establishing Temporal Duration of Two Shield Volcanoes in Northern California
This dataset contains paleomagnetic data from 30 sites at two locations in northern California (16 sites at Ash Creek Butte and 14 sites at Crater Mountain), magnetic susceptibility-temperature curves for selected samples at Ash Creek Butte, and geochemical data for map units at Crater Mountain.Hazard zone boundaries for the volcano hazards assessment for the Lassen region, Northern California
This report evaluates the volcano-related hazards, including regional mafic lava flows, silicic lava domes, pyroclastic flows, lahars, and volcanic ash, of the Lassen region, California, which is here defined as an area between the Pit River on the north and the southern limit of active Cascade volcanism, approximately 5-10 km south of the southern boundary of Lassen Volcanic National Park. Most aDatabase for the Geologic Map of the Lassen Peak, Chaos Crags, and Upper Hat Creek Area, California
This is a database of the geologic map of the Lassen Peak, Chaos Crags, and Upper Hat Creek volcanic area as described in the original abstract: The Lassen Peak, Chaos Crags, and Upper Hat Creek map area lies near the southern end of the Cascade Range in northern California. The map area includes parts of the three elements that together form the Lassen volcanic center: the Lassen dacitic do - Maps
Geologic map of Lassen Volcanic National Park and vicinity, California
The geologic map of Lassen Volcanic National Park (LVNP) and vicinity encompasses 1,905 km2 at the south end of the Cascade Range in Shasta, Lassen, Tehama, and Plumas Counties, northeastern California (fig. 1, sheet 3). The park includes 430 km2 of scenic volcanic features, glacially sculpted terrain, and the most spectacular array of thermal features in the Cascade Range. Interest in preservingGeologic Map of Lassen Volcanic National Park and Vicinity, California
The geologic map of Lassen Volcanic National Park (LVNP) and vicinity encompasses 1,905 km2 at the south end of the Cascade Range in Shasta, Lassen, Tehama, and Plumas Counties, northeastern California (fig. 1, sheet 3). The park includes 430 km2 of scenic volcanic features, glacially sculpted terrain, and the most spectacular array of thermal features in the Cascade Range. Interest in preservingGeologic map of the Lassen Peak, Chaos Crags, and Upper Hat Creek area, California
This digital publication contains all the information used to publish U.S. Geological Survey Geologic Investigations Series I-2723 (Christiansen and others, 2002). The map shows the distribution and relationships of volcanic and surficial-sedimentary deposits in an area of Lassen Volcanic National Park and vicinity. Emphasis is on products of the 1914-1917 eruptions of Lassen Peak and the approxim - Publications
Filter Total Items: 46
lawilátɬa—Mount St. Helens—Land in transformation
This poster provides an overview of Mount St. Helens’ eruption history and emphasizes the continuous transformation of the volcanic landscape and its ecosystems. After each eruption, the landscape and ecosystems are not so much restored as they are morphed into new forms and patterns.AuthorsCarolyn L. Driedger, Alysa Adams, Michael A. Clynne, Kristi Cochrane, Abi Groskopf, Emma Johnson, Heather Monti, Elizabeth WestbyDevelopment of a volcanic risk management system at Mount St. Helens—1980 to present
Here, we review volcanic risk management at Mount St. Helens from the perspective of the US Geological Survey’s (USGS) experience over the four decades since its 18 May 1980 climactic eruption. Prior to 1980, volcano monitoring, multidisciplinary eruption forecasting, and interagency coordination for eruption response were new to the Cascade Range. A Mount St. Helens volcano hazards assessment hadAuthorsHeather M. Wright, Carolyn L. Driedger, John S. Pallister, Christopher G. Newhall, Michael A. Clynne, John W. EwertPaleomagnetically defined brief lifespans for two large shield volcanoes in the Cascades Arc
Mafic to intermediate shield volcanoes with multi-cubic-kilometer eruptive volumes are common in the Cascades Volcanic Arc, but little is known about their eruptive histories as either singular or sustained episodes, or the total time required for their construction. Paleomagnetic data were collected from the lava flows of Ash Creek Butte (17 sites) and Crater Mountain (14 sites) in northern CalifAuthorsAnthony Francis Pivarunas, Dawnika Blatter, L. J. Patrick Muffler, Michael A. Clynne, Andrew T. Calvert, Lauren N Harrison, R.L. ChristiansenA multidisciplinary investigation into the eruptive style, processes, and duration of a Cascades back-arc tholeiitic basalt: A case study of the Brushy Butte flow field, northern California, United States
The Cascades back-arc in northern California is dominated by monogenetic tholeiitic basalts that erupted throughout the Pleistocene. Elucidating their eruptive history and processes is important for understanding potential future eruptions here. We focus on the well-exposed monogenetic volcano that emplaced the Brushy Butte flow field, which constructed a ∼150 m tall edifice, has flow lobes up toAuthorsDrew T. Downs, Duane E. Champion, Michael A. Clynne, L. J. Patrick MufflerSimultaneous Middle Pleistocene eruption of three widespread tholeiitic basalts in northern California (USA): Insights into crustal magma transport in an actively extending back arc
Mapping and chronology are central to understanding spatiotemporal volcanic trends in diverse tectonic settings. The Cascades back arc in northern California (USA) hosts abundant lava flows and normal faults, but tholeiitic basalts older than 200 ka are difficult to discriminate by classic mapping methods. Paleomagnetism and chemistry offer independent means of correlating basalts, including the TAuthorsDrew T. Downs, Duane E. Champion, L. J. Patrick Muffler, Robert L. Christiansen, Michael A. Clynne, Andrew T. CalvertTen ways Mount St. Helens changed our world—The enduring legacy of the 1980 eruption
Mount St. Helens was once enjoyed for its serene beauty and was considered one of America’s most majestic volcanoes because of its perfect cone shape, similar to Japan’s beloved Mount Fuji. Nearby residents assumed that the mountain was solid and enduring. That perception changed during the early spring of 1980. Then, on May 18, 1980, following 2 months of earthquakes and small explosions, the volAuthorsCarolyn L. Driedger, Jon J. Major, John S. Pallister, Michael A. Clynne, Seth C. Moran, Elizabeth G. Westby, John W. EwertField trip guide to Mount St. Helens, Washington—Recent and ancient volcaniclastic processes and deposits
This field guide explores volcanic effusions, sediments, and landforms at Mount St. Helens in Washington. A detailed synopsis outlines the eruptive history of Mount St. Helens from about 300,000 years ago through 1980 and beyond.The five days in the field include about 28 stops and 12 potential stops. Exposures in valleys surrounding Mount St. Helens reveal records of diverse Pleistocene and HolocAuthorsRichard B. Waitt, Jon J. Major, Richard P. Hoblitt, Alexa R. Van Eaton, Michael A. ClynneEruption age and duration of the ~9 km3 Burney Mountain dacite dome complex, northern California
At ~9 km3, the six dacite domes of Burney Mountain (db1–db6) constitute the most voluminous Quaternary dome complex in the Cascades volcanic arc. Whole-rock geochemistry, electron microprobe, and petrographic data indicate that the domes are magmatically related, which, when integrated with geomorphology and stratigraphy, indicate early (db1, db2, db3) and late (db4, db5, db6) erupted groups. WeAuthorsDrew T. Downs, Michael A. Clynne, Duane E. Champion, L. J. Patrick MufflerTemporal relationship between the Lassen Volcanic Center and mafic regional volcanism
Monogenetic volcanoes, distributed over large areas, contribute to the growth of monogenetic volcanic fields (MVFs) over thousands to millions of years of activity. It is now accepted that MVFs are also temporally clustered. To reduce uncertainties inherent to this episodic character, it is critical to combine multi-disciplinary studies to improve our knowledge of the temporal evolution of MVFs. TAuthorsAurelie Germa, Chris Perry, Xavier Quidelleur, Andrew T. Calvert, Michael A. Clynne, Chuck Connor, Laura Connor, Rocco Malservisi, Sylvain CharbonnierUnderstanding melt evolution and eruption dynamics of the 1666 C.E. eruption of Cinder Cone, Lassen Volcanic National Park, California: Insights from olivine-hosted melt inclusions
Cinder Cone is the youngest scoria cone volcano in the continental United States. Erupted in 1666 C.E. within what is now Lassen Volcanic National Park, Cinder Cone is an un-vegetated scoria cone with well-preserved lava flows and tephra deposits that display complex geochemical variability. In this study, we utilize the volatile (H2O, CO2, Cl), major, and trace element chemistry of olivine-hostedAuthorsKristina J Walowski, P.J. Wallace, K.V. Cashman, J.K. Marks, Michael A. Clynne, P. RuprechtPleistocene hydrothermal activity on Brokeoff volcano and in the Maidu volcanic center, Lassen Peak area, northeast California: Evolution of magmatic-hydrothermal systems on stratovolcanoes
Partially eroded stratovolcanoes worldwide, notably Mounts Rainier and Adams in the Cascades and several volcanoes in Japan, record episodic periods of eruption and geothermal activity that produce zones of hydrothermal alteration. The partly eroded core of late Pleistocene Brokeoff volcano on the south side of Lassen Peak exposes the upper 1 km of multiple ancient (ca. 410–300 ka) magmatic-hydrotAuthorsDavid John, Robert G. Lee, George N. Breit, John H. Dilles, Andrew T. Calvert, L. J. Patrick Muffler, Michael A. ClynneA re-examination of the three most prominent Holocene tephra deposits in western Canada: Bridge River, Mount St. Helens Yn and Mazama
Volcanic ash deposits (tephra) in western Canada are instrumental in providing independent chronologic control for many archaeological and paleoenvironmental sites. In Alberta, tephra are a key chronologic tool in a region where radiocarbon dates are often unreliable because of the prevalence of carbonate-rich bedrock and other “old carbon” sources, such as coal. However, many studies using tephraAuthorsBritta J.L. Jensen, Alwynne B. Beaudoin, Michael A. Clynne, Jordan Harvey, James W. VallanceNon-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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*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