Tom Parsons
I conduct research aimed at improving our ability to forecast hazardous events like earthquakes and tsunamis. Specifically, I study how earthquakes trigger others, how crustal movements cause earthquake stresses, and how to convert geologic observations of earthquake and tsunami processes into quantitative forecasts of use to planners, insurers, and builders.
Professional Experience
1994-Present: Research Geophysicist, U. S. Geological Survey, Menlo Park, CA
1992-1994: National Research Council Postdoctoral Fellow
Education and Certifications
1992 – Ph.D. in Geophysics, Stanford University
1990 – M.S. in Geophysics, Stanford University
1988 – B.S. in Applied Geophysics, UCLA
Affiliations and Memberships*
Editor, AGU Advances, 2019-present
Editor in Chief, Journal of Geophysical Research, Solid Earth, 2009-2015
Editor in Chief, Tectonophysics, 2007-2009
Editorial Board, Tectonophysics, 2005-2007
Editorial Board, Geology, 1995-2000, 2005-2008
Member: Executive Committee, Working Group on California Earthquake Probabilities 2005-present
Member: SCEC Planning Committee, 2007-2009
Honors and Awards
Senior Scientist (ST): 1/15
Fellow American Geophysical Union, Elected 1/12
Fulbright Mutual Educational Exchange Grant USA-Greece: 2007-2008
Alumni Pillar of Achievement: Golden West College Outstanding Alumni Award (10/07)
Fellow Geological Society of America, Elected 10/97
Shoemaker Communication Award (10/00)
National Association of Government Communicators Gold Screen Award (12/00)
National Research Council Post-Doctoral Fellow (8/92)
Science and Products
Editorial: Exploring new frontiers with JGR–Solid Earth
Earth science: lasting earthquake legacy
Three‐dimensional model of Hellenic Arc deformation and origin of the Cretan uplift
Is there a basis for preferring characteristic earthquakes over a Gutenberg–Richter distribution in probabilistic earthquake forecasting?
Assessment of source probabilities for potential tsunamis affecting the U.S. Atlantic coast
Probabilistic tsunami hazard assessment at Seaside, Oregon, for near-and far-field seismic sources
On near-source earthquake triggering
Can footwall unloading explain late Cenozoic uplift of the Sierra Nevada crest?
Comments on potential geologic and seismic hazards affecting proposed liquefied natural gas site in Santa Monica Bay, California
A global search for stress shadows
Global ubiquity of dynamic earthquake triggering
Development of final a-fault rupture models for WGCEP/ NSHMP Earthquake Rate Model 2
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
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Filter Total Items: 116
Editorial: Exploring new frontiers with JGR–Solid Earth
No abstract available.AuthorsRobert L. Nowack, Tom Parsons, André RevilEarth science: lasting earthquake legacy
Earthquakes occur within continental tectonic plates as well as at plate boundaries. Do clusters of such mid-plate events constitute zones of continuing hazard, or are they aftershocks of long-past earthquakes? Early on the morning of 16 December 1811, an earthquake of about magnitude 7 shook the centre of the United States around a small town on the Mississippi called New Madrid. By 7 February 18AuthorsThomas E. ParsonsThree‐dimensional model of Hellenic Arc deformation and origin of the Cretan uplift
[1] The Hellenic Arc of Greece is the most seismically active part of Europe, but little is know about its mechanics. We modeled deformation along the arc using a finite element model. The model was intended to capture large‐scale 3‐D structure of Nubian plate subduction beneath the Aegean block and its deformational consequences. The shape of the interface was developed using mapped traces at theAuthorsAthanassios Ganas, Tom ParsonsIs there a basis for preferring characteristic earthquakes over a Gutenberg–Richter distribution in probabilistic earthquake forecasting?
The idea that faults rupture in repeated, characteristic earthquakes is central to most probabilistic earthquake forecasts. The concept is elegant in its simplicity, and if the same event has repeated itself multiple times in the past, we might anticipate the next. In practice however, assembling a fault-segmented characteristic earthquake rupture model can grow into a complex task laden with unquAuthorsThomas E. Parsons, Eric L. GeistAssessment of source probabilities for potential tsunamis affecting the U.S. Atlantic coast
Estimating the likelihood of tsunamis occurring along the U.S. Atlantic coast critically depends on knowledge of tsunami source probability. We review available information on both earthquake and landslide probabilities from potential sources that could generate local and transoceanic tsunamis. Estimating source probability includes defining both size and recurrence distributions for earthquakes aAuthorsE.L. Geist, T. ParsonsProbabilistic tsunami hazard assessment at Seaside, Oregon, for near-and far-field seismic sources
The first probabilistic tsunami flooding maps have been developed. The methodology, called probabilistic tsunami hazard assessment (PTHA), integrates tsunami inundation modeling with methods of probabilistic seismic hazard assessment (PSHA). Application of the methodology to Seaside, Oregon, has yielded estimates of the spatial distribution of 100- and 500-year maximum tsunami amplitudes, i.e., amAuthorsF.I. Gonzalez, E.L. Geist, B. Jaffe, U. Kanoglu, H. Mofjeld, C.E. Synolakis, V.V. Titov, D. Areas, D. Bellomo, D. Carlton, T. Horning, J. Johnson, J. Newman, T. Parsons, R. Peters, C. Peterson, G. Priest, A. Venturato, J. Weber, F. Wong, A. YalcinerOn near-source earthquake triggering
[1] When one earthquake triggers others nearby, what connects them? Two processes are observed: static stress change from fault offset and dynamic stress changes from passing seismic waves. In the near-source region (r ≤ 50 km for M ∼ 5 sources) both processes may be operating, and since both mechanisms are expected to raise earthquake rates, it is difficult to isolate them. We thus compare explosAuthorsT. Parsons, A.A. VelascoCan footwall unloading explain late Cenozoic uplift of the Sierra Nevada crest?
Globally, normal-fault displacement bends and warps rift flanks upwards, as adjoining basins drop downwards. Perhaps the most evident manifestations are the flanks of the East African Rift, which cuts across the otherwise minimally deformed continent. Flank uplift was explained by Vening Meinesz (1950, Institut Royal Colonial Belge, Bulletin des Seances, v. 21, p. 539-552), who recognized that isoAuthorsG. A. Thompson, T. ParsonsComments on potential geologic and seismic hazards affecting proposed liquefied natural gas site in Santa Monica Bay, California
In a letter to the U.S. Geological Survey (USGS) dated March 25, 2008, Representative Jane Harman (California 36th district) requested advice on geologic hazards that should be considered in the review of a proposed liquefied natural gas (LNG) facility off the California coast in Santa Monica Bay. In 2004, the USGS responded to a similar request from Representative Lois Capps, regarding two proposAuthorsStephanie L. Ross, Homa J. Lee, Tom E. Parsons, Larry A. Beyer, David M. Boore, James E. Conrad, Brian D. Edwards, Michael A. Fisher, Arthur D. Frankel, Eric L. Geist, Kenneth W. Hudnut, Susan E. Hough, Robert E. Kayen, T.D. Lorenson, Nicolas Luco, Patricia A. McCrory, Mary McGann, Manuel Nathenson, Michael Nolan, Mark D. Petersen, Daniel J. Ponti, Charles L. Powell, Holly F. Ryan, John C. Tinsley, Chris J. Wills, Florence L. Wong, Jingping XuA global search for stress shadows
[1] Debate continues regarding the relative proportion of earthquakes triggered by passing seismic waves versus static stress changes from a main shock. Static stress changes are expected to have long‐term effects on earthquake probabilities, whereas dynamic stress changes due to the passing of seismic waves should not. Both mechanisms are expected to raise seismicity rates in some areas, but onlyAuthorsEllen P. Mallman, Tom ParsonsGlobal ubiquity of dynamic earthquake triggering
Earthquakes can be triggered by local changes in the stress field (static triggering1,2,3,4,5,6,7) due to nearby earthquakes or by stresses caused by the passage of surface (Rayleigh and Love) waves from a remote, large earthquake (dynamic triggering8,9,10,11,12,13,14,15,16,17,18). However, the mechanism, frequency, controlling factors and the global extent of dynamic triggering are yet to be fullAuthorsAaron A. Velasco, Stephen Hernandez, Tom Parsons, Kris PankowDevelopment of final a-fault rupture models for WGCEP/ NSHMP Earthquake Rate Model 2
This appendix discusses how we compute the magnitude and rate of earthquake ruptures for the seven Type-A faults (Elsinore, Garlock, San Jacinto, S. San Andreas, N. San Andreas, Hayward-Rodgers Creek, and Calaveras) in the WGCEP/NSHMP Earthquake Rate Model 2 (referred to as ERM 2. hereafter). By definition, Type-A faults are those that have relatively abundant paleoseismic information (e.g., meanAuthorsEdward H. Field, Ray J. Weldon, Thomas Parsons, Chris J. Wills, Timothy E. Dawson, Ross S. Stein, Mark D. PetersenNon-USGS Publications**
1992, by Parsons, T. et al., Department of Geophysics, Stanford University1992, by Parsons, T., et al., Department of Geophysics, Stanford University1991, by Howie, J.M., et al., Department of Geophysics, Stanford University1991, by Parsons, T., and Thompson, G.A., Department of Geophysics, Stanford University**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