Eric Geist


Eric Geist is a research geophysicist with the U.S. Geological Survey in Moffett Field/Menlo Park, California, where he has worked for over three decades.  Throughout his career, he has focused on computer modeling of geophysical phenomena, including large-scale deformation of the earth in response to tectonic forces and the physics of tsunami generation.  For the last ten years, his research has focused on improving our ability to forecast tsunamis and their sources.  Eric has authored over 120 journal articles and abstracts, including an article in Scientific American on the devastating 2004 Indian Ocean tsunami and several review papers on tsunamis.

Research Statement

Natural hazards are the product of complex physical systems.  Eric’s research currently focuses on the new field of earthquake combinatorics.  This research examines combinations and arrangements of earthquakes on faults to explain a variety of geophysical and geological datasets.  Tackling the size of combinatorial problems for fault-scale systems has only recently been made possible through advances in applied mathematics and computer science over the last decade.  With newly developed computer algorithms, earthquake combinatorics provides an avenue to investigate earthquake hazards for both offshore and onshore faults.

Eric also investigates the interplay between nonlinear dynamics and a probabilistic description of geophysical processes, particularly as applied to natural hazards and their sources.  Recent developments in statistical physics provide many avenues for understanding natural hazards, including how source sizes and outcomes are distributed and how individual natural hazard events occur through time. In addition, stochastic models provide a way to quantify uncertainty associated with source processes as applied to hazard assessments. A natural product of this research is development of new probabilistic methods to forecast natural hazards.

Eric has also examined nonlinear processes associated with long-term and large-scale deformation of the Earth’s lithosphere.  Specific projects have included understanding the seismotectonics of island arcs and determining the state of stress and slip rates along major plate-boundary fault systems.



1985 - M.Sc. in Geophysics, Stanford University

1983 – B.Sc. in Geophysical Engineering, Colorado School of Mines



1992 – Present:  Research Geophysicist, U.S. Geological Survey, Menlo Park, CA

1986 – 1991:  Operational Geophysicist, U.S. Geological Survey, Menlo Park, CA

1985 – 1986:  Physical Science Technician, U.S. Geological Survey, Menlo Park, CA


Honors and Awards

2002, 2011, 2018: American Geophysical Union, Editor’s Citation for Excellence in Refereeing

2005: USGS Western Region, Communicator of the Year Award (co-honoree)

1994: Department of the Interior Superior Service Award

1994: Fellow, Geological Society of America


Research Management

2012 – 2017: Co-Leader of Marine Geohazards Project, USGS

2005 – 2012: Co-Leader of Caribbean Tsunami Hazards Project, USGS

2004 – 2007: Co-Leader of FEMA Probabilistic Tsunami Pilot Study: Seaside, Oregon

1998 – 2004: Leader of Modeling and Probabilistic Analysis of Coastal Change Hazards Project, USGS

1989 – 1994: Leader of Geodynamic Modeling of Island Arcs Project, USGS


Selected Publications

If you do not have access to these publications, please contact me by email for reprints of any of these papers.

Earthquake Combinatorics

Geist, E. L., and Parsons, T., 2020, Distribution of Earthquakes on a Branching Fault System Using Integer Programming and Greedy-Sequential Methods, Geochemistry, Geophysics, Geosystems, v. 21, no. 9, e2020GC008964, doi:10.1029/2020GC008964.

Geist, E.L., and Parsons, T., 2019, A combinatorial approach to determine earthquake magnitude distributions on a variable slip-rate fault: Geophysical Journal International, v. 219, no. 2, p. 734-752, doi:10.1093/gji/ggz294.

Parsons, T., Geist, E.L., Console, R., and Carluccio, R., 2018, Characteristic earthquake magnitude frequency distributions on faults calculated from consensus data in California: Journal of Geophysical Research: Solid Earth, v. 123, no. 12, p. 10,761-710,784, doi:10.1029/2018JB016539

Geist, E.L., and Parsons, T., 2018, Determining on-fault earthquake magnitude distributions from integer programming: Computers & Geosciences, v. 111, p. 244-259, doi:10.1016/j.cageo.2017.11.018

Parsons, T., and Geist, E.L., 2009, Is there a basis for preferring characteristic earthquakes over a Gutenberg-Richter distribution in probabilistic earthquake forecasting?, Bulletin of the Seismological Society of America, v. 99, p. 2012-2019, doi:10.1785/0120080069


Probability of Tsunamis and Tsunami Sources

Geist, E.L., Oglesby, D.D., and Ryan, K.J. 2019, Tsunamis: Stochastic models of occurrence and generation mechanisms, in Meyers, R.A. (ed.), Encyclopedia of Complexity and Systems Science: Berlin, Springer, 30p., doi:10.1007/978-3-642-27737-5_595-2.

Geist, E.L., and ten Brink, U.S., 2019, Offshore landslide hazard curves from mapped landslide size distributions: Journal of Geophysical Research: Solid Earth, v. 124, p. 3320-3334, doi:10.1029/2018JB017236.

Grezio, A., Babeyko, A.Y., Baptista, A.M., Behrens, J., Costa, A., Davies, G., Geist, E.L., Glimsdal, S., González, F.I., Griffin, J., Harbitz, C.B., LeVeque, R.J., Lorito, S., Løvholt, F., Omira, R., Mueller, C.S., Paris, R., Parsons, T., Polet, J., Power, W., Selva, J., Sørensen, M.B., and Thio, H.K., 2017, Probabilistic Tsunami Hazard Analysis (PTHA): Multiple sources and global applications: Reviews of Geophysics, v. 55, doi:10.1002/2017RG000579.

Geist, E.L., and Parsons, T., 2016, Reconstruction of far-field tsunami amplitude distributions from earthquake sources: Pure and Applied Geophysics, v. 173, p. 3703-3717, doi:10.1007/s00024-00016-01288-x.

Geist, E.L., 2014, Explanation of temporal clustering of tsunami sources using the epidemic-type aftershock sequence model: Bulletin of the Seismological Society of America, v. 104, p. 2091-2103, doi:10.1785/0120130275

Geist, E.L., and Lynett, P.J., 2014, Source processes for the probabilistic assessment of tsunami hazards: Oceanography, v. 27, p. 86–93, doi:10.5670/oceanog.2014.43

Geist, E.L., and Parsons, T., 2014, Undersampling power-law size distributions: effect on the assessment of extreme natural hazards: Natural Hazards, v. 72, p. 565-595, doi:10.1007/s11069-013-1024-0

Geist, E.L., ten Brink, U.S., and Gove, M., 2014, A framework for the probabilistic analysis of meteotsunamis: Natural Hazards, doi:10.1007/s11069-014-1294-1

Parsons, T., and Geist, E.L., 2014, The 2010-2014.3 global earthquake rate increase: Geophysical Research Letters, v. 41, p. 4479-4485, doi:10.1002/2014GL060513

ten Brink, U.S., Chaytor, J.D., Geist, E.L., Brothers, D.S., and Andrews, B.D., 2014, Assessment of tsunami hazard to the U.S. Atlantic margin: Marine Geology, v. 353, pp. 31–54, doi:10.1016/j.margeo.2014.02.011

Geist, E.L., J.D. Chaytor, T. Parsons, and U. ten Brink, 2013, Estimation of submarine mass failure probability from a sequence of deposits with age dates, Geosphere, v. 9, p. 287-298, doi:10.1130/GES00829.1

Zoback, M. L., E. L. Geist, J. Pallister, D. Hill, S. Young, and W. McCausland, 2013, Advances in natural hazard science and assessment, 1963-2013, in The Impact of the Geological Sciences on Society, edited by M. E. Bickford, Geological Society of America Special Paper 501, Boulder, CO, p. 81-154

Parsons, T., Y. Ogata, J. Zhuang, and E. L. Geist, 2012, Evaluation of static stress change forecasting with prospective and blind tests, Geophys. J. Int., v. 188, p. 1425-1440, doi:10.1111/j.1365-246X.2011.05343.x

Parsons, T., and Geist, E.L., 2012, Were global M≥8.3 earthquake time intervals random between 1900-2011?: Bulletin of the Seismological Society of America, v. 102, p. 1583-1592, doi:10.1785/0120110282

Geist, E.L., 2012, Phenomenology of tsunamis II: Scaling, Event Statistics, and Inter-Event Triggering: Advances in Geophysics, v. 53, p. 35-92, doi:10.1016/B978-0-12-380938-4.00002-1

Geist, E.L., and Parsons, T., 2011, Assessing historical rate changes in global tsunami occurrence: Geophysical Journal International, v. 187, p. 497-509, doi:10.1111/j.1365-246X.2011.05160.x

Geist, E.L., 2009, Phenomenology of tsunamis: Statistical properties from generation to runup, Advances in Geophysics, v. 51, p. 107-169, doi:10.1016/S0065-2687(09)05108-5

Geist, E.L., and Parsons, T., 2009, Assessment of source probabilities for potential tsunamis affecting the U.S. Atlantic Coast, Marine Geology, v. 264, p. 98-108, doi:10.1016/j.margeo.2008.08.005

Geist, E.L., Parsons, T., ten Brink, U.S., and Lee, H.J., 2009, Tsunami Probability, in Bernard, E.N., and Robinson, A.R., eds., The Sea, v. 15: Cambridge, Massachusetts, Harvard University Press, p. 93-135

González, F.I., Geist, E.L., Jaffe, B.E., Kânoglu, U., Mofjeld, H.O., Synolakis, C.E., Titov, V.V., Arcas, D., Bellomo, D., Carlton, D., Horning, T.S., Johnson, J., Newman, J.C., Parsons, T., Peters, R., Peterson, C., Priest, G.R., Venturato, A.J., Weber, J., Wong, F., and Yalciner, A.C., 2009, Probabilistic tsunami hazard assessment at Seaside, Oregon for near- and far-field seismic sources, Journal of Geophysical Research, v. 114, doi:10.1029/2008JC005132

Parsons, T., and Geist, E.L., 2009, Is there a basis for preferring characteristic earthquakes over a Gutenberg-Richter distribution in probabilistic earthquake forecasting?, Bulletin of the Seismological Society of America, v. 99, p. 2012-2019, doi:10.1785/0120080069

Parsons, T., and Geist, E.L., 2008, Tsunami probability in the Caribbean region: Pure and Applied Geophysics, v. 165, p. 2089-1226, doi:10.1007/s00024-008-0416-7

Geist, E. L., and T. Parsons, 2008, Distribution of tsunami inter-event times, Geophysical Research Letters, v. 35, L02612, doi:101029/102007GL032690

Geist, E.L., and Parsons, T., 2006, Probabilistic analysis of tsunami hazards: Natural Hazards, v. 37, p. 277-314, doi:10.1007/s11069-005-4646-z

ten Brink, U.S., Geist, E.L., and Andrews, B.D., 2006, Size distribution of submarine landslides and its implication to tsunami hazard in Puerto Rico: Geophysical Research Letters, v. 33, L11307,doi:10.1029/2006GL026125

Geist, E.L., 2005, Local Tsunami Hazards in the Pacific Northwest from Cascadia Subduction Zone Earthquakes, USGS Professional Paper 1661B, 17 p.


Tsunami Generation

Geist, E.L., 2018, Effect of dynamical phase on the resonant interaction among tsunami edge wave modes: Pure and Applied Geophysics, v. 175, p. 1341-1354, doi: 10.1007/s00024-018-1796-y

Geist, E. L., 2016, Non-linear resonant coupling of tsunami edge waves using stochastic earthquake source models: Geophysical Journal International, v. 204, p. 878-891, doi: 10.1093/gji/ggv489

Ryan, K.J., Geist, E.L., Barall, M., and Oglesby, D.D., 2015, Dynamic models of an earthquake and tsunami offshore Ventura, California: Geophysical Research Letters, v. 42, p. 6599-6606, doi:10.1002/2015GL064507

Geist, E.L., and Oglesby, D.D., 2014, Earthquake Mechanism and seafloor deformation for tsunami generation, in Beer, M., Patelli, E., Kougioumtzoglou, I. A., Au, I. S.-K., Encyclopedia of Earthquake Engineering: Berlin, Springer, p. 17. doi:10.1007/978-3-642-36197-5_296-1

Parsons, T., E. L. Geist, H. F. Ryan, H. J. Lee, P. J. Haeussler, P. Lynett, P. E. Hart, R. Sliter, and E. Roland, 2014, Source and progression of a submarine landslide and tsunami: The 1964 Great Alaska earthquake at Valdez: Journal of Geophysical Research—Solid Earth, v. 119, i. 11, pp. 8502–8516, doi:10.1002/2014JB011514

Ishii, M., E. Kiser, and E. L. Geist, 2013, Mw 8.6 Sumatran earthquake of 11 April 2012: Rare seaward expression of oblique subduction, Geology, v. 41, p. 319-322, doi:10.1130/G33783.1

Geist, E.L., 2013, Near-field tsunami edge waves and complex earthquake rupture: Pure and Applied Geophysics, doi:10.1007/s00024-012-0491-7.

Geist, E.L., Lynett, P.J., and Chaytor, J.D., 2009, Hydrodynamic modeling of tsunamis from the Currituck landslide, Marine Geology, v. 264, p. 41-52, doi:10.1016/j.margeo.2008.09.005

Wendt, J., Oglesby, D.D., and Geist, E.L., 2009, Tsunamis and splay fault dynamics: Geophysical Research Letters, v. 36, L15303, doi:10.1029/2009GL038295.

Geist, E.L., Titov, V.V., Arcas, D., Pollitz, F.F., and Bilek, S.L., 2007, Implications of the 26 December Sumatra-Andaman earthquake on tsunami forecast and assessment models for great subduction-zone earthquakes: Bulletin of the Seismological Society of America, v. 97, p. S249-S270,doi:10.1785/0120050619.

Geist, E.L., Titov, V.V., and Synolakis, C.E., 2006, Tsunami: wave of change: Scientific American, v. 294, p. 56-63.

Geist, E.L., Bilek, S.L., Arcas, D., and Titov, V.V., 2006, Differences in tsunami generation between the December 26, 2004 and March 28, 2005 Sumatra earthquakes: Earth Planets Space, v. 58, p. 185-193

Geist, E.L., and Parsons, T., 2005, Triggering of Tsunamigenic Aftershocks from Large Strike-Slip Earthquakes: Analysis of the November 2000 New Ireland Earthquake Sequence: Geochemistry, Geophysics, Geosystems, v. 6, Q10005, doi:10.1029/2005GC000935

Hirata, K., Geist, E.L., Satake, K., Tanioka, Y., and Yamaki, S., 2003, Slip distribution of the 1952 Tokachi-Oki earthquake (M 8.1) along the Kuril Trench deduced from tsunami waveform inversion: Journal of Geophysical Research, v. 108, no. B4, p. ESE 6-1 - ESE 6-15, doi:10.1029/2002JB001976.

Hirata, K., Takahashi, H., Geist, E., Satake, K., Tanioka, Y., Sugioka, H., and Mikada, H., 2003, Source depth dependence of micro-tsunamis recorded with ocean-bottom pressure gauges; the January 28, 2000 Mw 6.8 earthquake off Nemuro Peninsula, Japan: Earth and Planetary Science Letters, v. 208, no. 3-4, p. 305-318, doi:10.1016/S0012-821X(03)00040-2.

Parsons, T., Sliter, R., Geist, E. L., Jachens, R. C., Jaffe, B. E., Foxgrover, A., Hart, P. E., and McCarthy, J., 2003, Structure and mechanics of the Hayward-Rodgers Creek fault step-over, San Francsico Bay, California: Bulletin of the Seismological Society of America, v. 93, p. 2187-2200

Geist, E.L., 2002, Complex earthquake rupture and local tsunamis: Journal of Geophysical Research, v. 107, p. ESE 2-1 - ESE 2-16, doi:10.1029/2000JB000139

Geist, E.L., and Zoback, M.L., 2002, Chapter 4, Examination of the tsunami generated by the 1906 San Francisco Mw = 7.8 earthquake, using new interpretations of the offshore San Andreas Fault, in Parsons, T., ed., Crustal Structure of the Coastal and Marine San Francisco Bay Region, California: USGS Professional Paper 1658, p. 29-42, doi:10.3133/pp1658.

Geist, E.L., and Bilek, S.L., 2001, Effect of depth-dependent shear modulus on tsunami generation along subduction zones: Geophysical Research Letters, v. 28, no. 7, p. 1315-1318.

Geist, E.L., 2000, Origin of the 17 July 1998 Papua New Guinea tsunami: Earthquake or landslide?: Seismological Research Letters, v. 71, no. 3, p. 344-351.

Geist, E.L., and Dmowska, R., 1999, Local tsunamis and distributed slip at the source: Pure and Applied Geophysics, v. 154, p. 485-512

Geist, E.L., and Zoback, M.L., 1999, Analysis of the tsunami generated by the Mw 7.8 1906 San Francisco earthquake: Geology, v. 27, p. 15-18

Geist, E.L., 1998, Local tsunamis and earthquake source parameters: Advances in Geophysics, v. 39, p. 117-209


Tectonic Modeling

Geist, E.L., and Andrews, D.J., 2000, Slip rates on San Francisco Bay area faults from anelastic deformation of the continental lithosphere: Journal of Geophysical Research, v. 105, no. B11, p. 25,543-25,552

Geist, E.L., 1996, Relationship between the present-day stress field and plate boundary forces in the Pacific Northwest: Geophysical Research Letters, v. 23, no. 23, p. 3381-3384

Geist, E.L., and Scholl, D.W., 1994, Large-scale deformation related to the collision of the Aleutian Arc with Kamchatka: Tectonics, v. 13, no. 2, p. 538-560

Geist, E.L., Fisher, M.A., and Scholl, D.W., 1993, Large-scale deformation associated with ridge subduction: Geophysical Journal International, v. 115, p. 344-366

Geist, E.L., and Scholl, D.W., 1992, Application of continuum models to deformation of the Aleutian Island Arc: Journal of Geophysical Research, v. 97, p. 4953-4967

Geist, E.L., Childs, J.R., and Scholl, D.W., 1988, The origin of summit basins of the Aleutian Ridge:  Implications for block rotation of an arc massif: Tectonics, v. 7, no. 2, p. 327-341