Rich Briggs
My work focuses on the geology and seismotectonics of large earthquakes, with the goal of understanding how, where, and why they happen.
Research Focus
I characterize active faults for seismic hazard analysis. This requires grappling with structures and processes that control earthquakes. I also work with the USGS National Earthquake Information Center (NEIC) to respond to large earthquakes by conducting rapid field studies and analyzing remote sensing products.
Professional Preparation
BS, Geologic and Environmental Science, Stanford University, 1999
PhD, Geology, Center for Neotectonic Studies, University of Nevada, Reno, 2004
Postdoctoral Scholar, Tectonics Observatory, California Institute of Technology, 2005-2008
Professional Experience
Research Geologist, U.S. Geological Survey, Golden, CO, 2008-present
Geologist, Synergetics Incorporated, Fort Collins, CO (contracted to USGS), 2008
Science and Products
Filter Total Items: 23
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Gravitational body forces focus North American intraplate earthquakes
Earthquakes far from tectonic plate boundaries generally exploit ancient faults, but not all intraplate faults are equally active. The North American Great Plains exemplify such intraplate earthquake localization, with both natural and induced seismicity generally clustered in discrete zones. Here we use seismic velocity, gravity and topography to generate a 3D lithospheric density model of the re
Authors
William Brower Levandowski, Mark Zellman, Richard W. Briggs
Tectonic summaries of magnitude 7 and greater earthquakes from 2000 to 2015
This paper describes the tectonic summaries for all magnitude 7 and larger earthquakes in the period 2000–2015, as produced by the U.S. Geological Survey National Earthquake Information Center during their routine response operations to global earthquakes. The goal of such summaries is to provide important event-specific information to the public rapidly and concisely, such that recent earthquakes
Authors
Gavin P. Hayes, Emma K. Meyers, James W. Dewey, Richard W. Briggs, Paul S. Earle, Harley M. Benz, Gregory M. Smoczyk, Hanna E. Flamme, William D. Barnhart, Ryan D. Gold, Kevin P. Furlong
Introduction to the special issue on the 25 April 2015 Mw 7.8 Gorkha(Nepal) earthquake
On April 25, 2015, a moment magnitude (Mw) 7.8 earthquake struck central Nepal, breaking a section of the broader Himalayan Front that had been largely quiescent in moderate-to-large earthquakes for much of the modern seismological era. Ground shaking associated with the event resulted in a broad distribution of triggered avalanches and landslides. The ensuing aftershock sequence was punctuated by
Authors
Gavin P. Hayes, Richard W. Briggs
Coseismic slip and early afterslip of the 2015 Illapel, Chile, earthquake: Implications for frictional heterogeneity and coastal uplift
Great subduction earthquakes are thought to rupture portions of the megathrust, where interseismic coupling is high and velocity-weakening frictional behavior is dominant, releasing elastic deformation accrued over a seismic cycle. Conversely, postseismic afterslip is assumed to occur primarily in regions of velocity-strengthening frictional characteristics that may correlate with lower interseism
Authors
William D. Barnhart, Jessica R. Murray, Richard W. Briggs, Francisco Gomez, Charles P. J. Miles, Jerry L. Svarc, Sebástian Riquelme, Bryan J. Stressler
Terrestrial cosmogenic surface exposure dating of glacial and associated landforms in the Ruby Mountains-East Humboldt Range of central Nevada and along the northeastern flank of the Sierra Nevada
Deposits near Lamoille in the Ruby Mountains-East Humboldt Range of central Nevada and at Woodfords on the eastern edge of the Sierra Nevada each record two distinct glacial advances. We compare independent assessments of terrestrial cosmogenic nuclide (TCN) surface exposure ages for glacial deposits that we have determined to those obtained by others at the two sites. At each site, TCN ages of bo
Authors
Steven G. Wesnousky, Richard W. Briggs, Marc W. Caffee, Rick J. Ryerson, Robert C. Finkel, Lewis A. Owen
Coral 13C/12C records of vertical seafloor displacement during megathrust earthquakes west of Sumatra
The recent surge of megathrust earthquakes and tsunami disasters has highlighted the need for a comprehensive understanding of earthquake cycles along convergent plate boundaries. Space geodesy has been used to document recent crustal deformation patterns with unprecedented precision, however the production of long paleogeodetic records of vertical seafloor motion is still a major challenge. Here
Authors
Michael K. Gagan, Sindia M. Sosdian, Heather Scott-Gagan, Kerry Sieh, Wahyoe S. Hantoro, Danny H. Natawidjaja, Richard W. Briggs, Bambang W. Suwargadi, Hamdi Rifai
Rapid characterization of the 2015 Mw 7.8 Gorkha, Nepal, earthquake sequence and its seismotectonic context
Earthquake response and related information products are important for placing recent seismic events into context and particularly for understanding the impact earthquakes can have on the regional community and its infrastructure. These tools are even more useful if they are available quickly, ahead of detailed information from the areas affected by such earthquakes. Here we provide an overview of
Authors
Gavin P. Hayes, Richard W. Briggs, William D. Barnhart, William L. Yeck, Daniel E. McNamara, David J. Wald, Jennifer Nealy, Harley M. Benz, Ryan D. Gold, Kishor S. Jaiswal, Kristin Marano, Paul S. Earle, Mike Hearne, Gregory M. Smoczyk, Lisa A. Wald, Sergey Samsonov
Unusually large tsunamis frequent a currently creeping part of the Aleutian megathrust
Current models used to assess earthquake and tsunami hazards are inadequate where creep dominates a subduction megathrust. Here we report geological evidence for large tsunamis, occurring on average every 300–340 years, near the source areas of the 1946 and 1957 Aleutian tsunamis. These areas bookend a postulated seismic gap over 200 km long where modern geodetic measurements indicate that the meg
Authors
Robert C. Witter, G. A. Carver, Richard W. Briggs, Guy R. Gelfenbaum, R.D. Koehler, SeanPaul M. La Selle, Adrian M. Bender, S.E. Engelhart, E. Hemphill-Haley, Troy D. Hill
Reactivated faulting near Cushing, Oklahoma: Increased potential for a triggered earthquake in an area of United States strategic infrastructure
In October 2014 two moderate-sized earthquakes (Mw 4.0 and 4.3) struck south of Cushing, Oklahoma, below the largest crude oil storage facility in the world. Combined analysis of the spatial distribution of earthquakes and regional moment tensor focal mechanisms indicate reactivation of a subsurface unnamed and unmapped left-lateral strike-slip fault. Coulomb failure stress change calculations usi
Authors
Daniel E. McNamara, Gavin P. Hayes, Harley M. Benz, Robert Williams, Nicole D McMahon, R.C. Aster, Austin F. Holland, T Sickbert, Robert B. Herrmann, Richard W. Briggs, Gregory M. Smoczyk, Eric Bergman, Paul S. Earle
A random-walk algorithm for modeling lithospheric density and the role of body forces in the evolution of the Midcontinent Rift
This paper develops a Monte Carlo algorithm for extracting three-dimensional lithospheric density models from geophysical data. Empirical scaling relationships between velocity and density create a 3D starting density model, which is then iteratively refined until it reproduces observed gravity and topography. This approach permits deviations from uniform crustal velocity-density scaling, which pr
Authors
William Brower Levandowski, Oliver S. Boyd, Richard W. Briggs, Ryan D. Gold
On- and off-fault deformation associated with the September 2013 Mw7.7 Balochistan earthquake: Implications for geologic slip rate measurements
The 24 September 2013 Mw7.7 Balochistan, Pakistan earthquake ruptured a ~ 200 km-long stretch of the Hoshab fault in southern Pakistan and produced the second-largest lateral surface displacement observed for a continental strike-slip earthquake. We remotely measured surface deformation associated with this event using high-resolution (0.5 m) pre- and post-event satellite optical imagery. We docum
Authors
Ryan D. Gold, Nadine G. Reitman, Richard W. Briggs, William D. Barnhart, Gavin P. Hayes, Earl M. Wilson
Tsunami recurrence in the eastern Alaska-Aleutian arc: A Holocene stratigraphic record from Chirikof Island, Alaska
Despite the role of the Alaska-Aleutian megathrust as the source of some of the largest earthquakes and tsunamis, the history of its pre–twentieth century tsunamis is largely unknown west of the rupture zone of the great (magnitude, M 9.2) 1964 earthquake. Stratigraphy in core transects at two boggy lowland sites on Chirikof Island’s southwest coast preserves tsunami deposits dating from the postg
Authors
Alan R. Nelson, Richard W. Briggs, Tina Dura, Simon E. Engelhart, Guy Gelfenbaum, Lee-Ann Bradley, S.L. Forman, Christopher H. Vane, K.A. Kelley
Science and Products
Filter Total Items: 23
No Result Found
Filter Total Items: 60
Gravitational body forces focus North American intraplate earthquakes
Earthquakes far from tectonic plate boundaries generally exploit ancient faults, but not all intraplate faults are equally active. The North American Great Plains exemplify such intraplate earthquake localization, with both natural and induced seismicity generally clustered in discrete zones. Here we use seismic velocity, gravity and topography to generate a 3D lithospheric density model of the re
Authors
William Brower Levandowski, Mark Zellman, Richard W. Briggs
Tectonic summaries of magnitude 7 and greater earthquakes from 2000 to 2015
This paper describes the tectonic summaries for all magnitude 7 and larger earthquakes in the period 2000–2015, as produced by the U.S. Geological Survey National Earthquake Information Center during their routine response operations to global earthquakes. The goal of such summaries is to provide important event-specific information to the public rapidly and concisely, such that recent earthquakes
Authors
Gavin P. Hayes, Emma K. Meyers, James W. Dewey, Richard W. Briggs, Paul S. Earle, Harley M. Benz, Gregory M. Smoczyk, Hanna E. Flamme, William D. Barnhart, Ryan D. Gold, Kevin P. Furlong
Introduction to the special issue on the 25 April 2015 Mw 7.8 Gorkha(Nepal) earthquake
On April 25, 2015, a moment magnitude (Mw) 7.8 earthquake struck central Nepal, breaking a section of the broader Himalayan Front that had been largely quiescent in moderate-to-large earthquakes for much of the modern seismological era. Ground shaking associated with the event resulted in a broad distribution of triggered avalanches and landslides. The ensuing aftershock sequence was punctuated by
Authors
Gavin P. Hayes, Richard W. Briggs
Coseismic slip and early afterslip of the 2015 Illapel, Chile, earthquake: Implications for frictional heterogeneity and coastal uplift
Great subduction earthquakes are thought to rupture portions of the megathrust, where interseismic coupling is high and velocity-weakening frictional behavior is dominant, releasing elastic deformation accrued over a seismic cycle. Conversely, postseismic afterslip is assumed to occur primarily in regions of velocity-strengthening frictional characteristics that may correlate with lower interseism
Authors
William D. Barnhart, Jessica R. Murray, Richard W. Briggs, Francisco Gomez, Charles P. J. Miles, Jerry L. Svarc, Sebástian Riquelme, Bryan J. Stressler
Terrestrial cosmogenic surface exposure dating of glacial and associated landforms in the Ruby Mountains-East Humboldt Range of central Nevada and along the northeastern flank of the Sierra Nevada
Deposits near Lamoille in the Ruby Mountains-East Humboldt Range of central Nevada and at Woodfords on the eastern edge of the Sierra Nevada each record two distinct glacial advances. We compare independent assessments of terrestrial cosmogenic nuclide (TCN) surface exposure ages for glacial deposits that we have determined to those obtained by others at the two sites. At each site, TCN ages of bo
Authors
Steven G. Wesnousky, Richard W. Briggs, Marc W. Caffee, Rick J. Ryerson, Robert C. Finkel, Lewis A. Owen
Coral 13C/12C records of vertical seafloor displacement during megathrust earthquakes west of Sumatra
The recent surge of megathrust earthquakes and tsunami disasters has highlighted the need for a comprehensive understanding of earthquake cycles along convergent plate boundaries. Space geodesy has been used to document recent crustal deformation patterns with unprecedented precision, however the production of long paleogeodetic records of vertical seafloor motion is still a major challenge. Here
Authors
Michael K. Gagan, Sindia M. Sosdian, Heather Scott-Gagan, Kerry Sieh, Wahyoe S. Hantoro, Danny H. Natawidjaja, Richard W. Briggs, Bambang W. Suwargadi, Hamdi Rifai
Rapid characterization of the 2015 Mw 7.8 Gorkha, Nepal, earthquake sequence and its seismotectonic context
Earthquake response and related information products are important for placing recent seismic events into context and particularly for understanding the impact earthquakes can have on the regional community and its infrastructure. These tools are even more useful if they are available quickly, ahead of detailed information from the areas affected by such earthquakes. Here we provide an overview of
Authors
Gavin P. Hayes, Richard W. Briggs, William D. Barnhart, William L. Yeck, Daniel E. McNamara, David J. Wald, Jennifer Nealy, Harley M. Benz, Ryan D. Gold, Kishor S. Jaiswal, Kristin Marano, Paul S. Earle, Mike Hearne, Gregory M. Smoczyk, Lisa A. Wald, Sergey Samsonov
Unusually large tsunamis frequent a currently creeping part of the Aleutian megathrust
Current models used to assess earthquake and tsunami hazards are inadequate where creep dominates a subduction megathrust. Here we report geological evidence for large tsunamis, occurring on average every 300–340 years, near the source areas of the 1946 and 1957 Aleutian tsunamis. These areas bookend a postulated seismic gap over 200 km long where modern geodetic measurements indicate that the meg
Authors
Robert C. Witter, G. A. Carver, Richard W. Briggs, Guy R. Gelfenbaum, R.D. Koehler, SeanPaul M. La Selle, Adrian M. Bender, S.E. Engelhart, E. Hemphill-Haley, Troy D. Hill
Reactivated faulting near Cushing, Oklahoma: Increased potential for a triggered earthquake in an area of United States strategic infrastructure
In October 2014 two moderate-sized earthquakes (Mw 4.0 and 4.3) struck south of Cushing, Oklahoma, below the largest crude oil storage facility in the world. Combined analysis of the spatial distribution of earthquakes and regional moment tensor focal mechanisms indicate reactivation of a subsurface unnamed and unmapped left-lateral strike-slip fault. Coulomb failure stress change calculations usi
Authors
Daniel E. McNamara, Gavin P. Hayes, Harley M. Benz, Robert Williams, Nicole D McMahon, R.C. Aster, Austin F. Holland, T Sickbert, Robert B. Herrmann, Richard W. Briggs, Gregory M. Smoczyk, Eric Bergman, Paul S. Earle
A random-walk algorithm for modeling lithospheric density and the role of body forces in the evolution of the Midcontinent Rift
This paper develops a Monte Carlo algorithm for extracting three-dimensional lithospheric density models from geophysical data. Empirical scaling relationships between velocity and density create a 3D starting density model, which is then iteratively refined until it reproduces observed gravity and topography. This approach permits deviations from uniform crustal velocity-density scaling, which pr
Authors
William Brower Levandowski, Oliver S. Boyd, Richard W. Briggs, Ryan D. Gold
On- and off-fault deformation associated with the September 2013 Mw7.7 Balochistan earthquake: Implications for geologic slip rate measurements
The 24 September 2013 Mw7.7 Balochistan, Pakistan earthquake ruptured a ~ 200 km-long stretch of the Hoshab fault in southern Pakistan and produced the second-largest lateral surface displacement observed for a continental strike-slip earthquake. We remotely measured surface deformation associated with this event using high-resolution (0.5 m) pre- and post-event satellite optical imagery. We docum
Authors
Ryan D. Gold, Nadine G. Reitman, Richard W. Briggs, William D. Barnhart, Gavin P. Hayes, Earl M. Wilson
Tsunami recurrence in the eastern Alaska-Aleutian arc: A Holocene stratigraphic record from Chirikof Island, Alaska
Despite the role of the Alaska-Aleutian megathrust as the source of some of the largest earthquakes and tsunamis, the history of its pre–twentieth century tsunamis is largely unknown west of the rupture zone of the great (magnitude, M 9.2) 1964 earthquake. Stratigraphy in core transects at two boggy lowland sites on Chirikof Island’s southwest coast preserves tsunami deposits dating from the postg
Authors
Alan R. Nelson, Richard W. Briggs, Tina Dura, Simon E. Engelhart, Guy Gelfenbaum, Lee-Ann Bradley, S.L. Forman, Christopher H. Vane, K.A. Kelley