Rich Briggs
My work focuses on the geology and seismotectonics of large earthquakes, with the goal of understanding how, where, and why they happen.
Biography
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
Geologic Cracks Record Earthquakes on the Reelfoot Fault in Central U.S.
Release Date: APRIL 25, 2019
New high-resolution lidar data reveals cracks produced from strong shaking in past earthquakes in the New Madrid seismic zone.
Untangling Faults at Depth – What Lies Beneath Panamint Valley, California?
Release Date: APRIL 30, 2018
The eastern edge of Panamint Valley,CA has two types of faults that can be seen in the near-surface geology. 150 geophones and a seismic source will help reveal the subsurface picture.
How Big and How Frequent Are Earthquakes on the Wasatch Fault?
Release Date: FEBRUARY 1, 2015
Paleoseismology along the Wasatch Fault in Utah is helping to estimate the shaking risk to nearby towns.
STEPS: Slip time earthquake path simulations applied to the San Andreas and Toe Jam Hill Faults to redefine geologic slip rate uncertainty
Geologic slip rates are a time-averaged measurement of fault displacement calculated over hundreds to million-year time scales and are a primary input for probabilistic seismic hazard analyses, which forecast expected ground shaking in future earthquakes. Despite their utility for seismic hazard calculations, longer-term geologic slip rates...
Hatem, Alexandra Elise; Gold, Ryan D.; Briggs, Richard W.; Scharer, Katherine; Field, Edward H. Quick and dirty (and accurate) 3-D paleoseismic trench models using coded scale bars
Structure‐from‐motion (SfM) modeling has dramatically increased the speed of generating geometrically accurate orthophoto mosaics of paleoseismic trenches, but some aspects of this technique remain time and labor intensive. Model accuracy relies on control points to establish scale, reduce distortion, and orient 3D models. Traditional SfM methods...
Delano, Jaime; Briggs, Richard W.; Duross, Christopher; Gold, Ryan D. Holocene paleoseismology of the Steamboat Mountain Site: Evidence for full‐Llngth rupture of the Teton Fault, Wyoming
The 72‐km‐long Teton fault in northwestern Wyoming is an ideal candidate for reconstructing the lateral extent of surface‐rupturing earthquakes and testing models of normal‐fault segmentation. To explore the history of earthquakes on the northern Teton fault, we hand‐excavated two trenches at the Steamboat Mountain site, where the east‐dipping...
Duross, Christopher; Zellman, Mark S.; Thackray, Glenn D.; Briggs, Richard W.; Gold, Ryan D.; Mahan, Shannon A. Seismic reflection imaging of the low-angle Panamint normal fault system, eastern California
Shallowly dipping (<30°) low‐angle normal faults (LANFs) have been documented globally; however, examples of active LANFs in continental settings are limited. The western margin of the Panamint Range in eastern California is defined by a LANF that dips west beneath Panamint Valley and has evidence of Quaternary motion. In addition, high‐angle...
Gold, Ryan D.; Stephenson, William J.; Briggs, Richard W.; Duross, Christopher; Kirby, Eric; Woolery, Edward W; Delano, Jaime; Odum, Jackson K. Evidence for late Quaternary deformation along Crowley's Ridge, New Madrid seismic zone
The New Madrid seismic zone has been the source of multiple major (M ~7.0–7.5) earthquakes in the past 2 ka, yet the surface expression of recent deformation remains ambiguous. Crowleys Ridge, a linear ridge trending north‐south for 300+ km through the Mississippi Embayment, has been interpreted as either a fault‐bounded uplift or a nontectonic...
Thompson Jobe, Jessica; Gold, Ryan D.; Briggs, Richard W.; Williams, Robert; Stephenson, William J.; Delano, Jaime E.; Shah, Anjana K.; Minsley, Burke J. Relaxing segmentation on the Wasatch Fault Zone: Impact on seismic hazard
The multisegment Wasatch fault zone is a well-studied normal fault in the western United States that has paleoseismic evidence of recurrent Holocene surface-faulting earthquakes. Along the 270-km-long central part of the fault, four primary structural complexities provide possible along-strike limits to these ruptures and form the basis for models...
Valentini, Alessandro; Duross, Christopher; Field, Edward H.; Gold, Ryan D.; Briggs, Richard W.; Visini, Francesco; Pace, Bruno Offset channels may not accurately record strike-slip fault displacement: Evidence from landscape evolution models
Slip distribution, slip rate, and slip per event for strike‐slip faults are commonly determined by correlating offset stream channels—under the assumption that they record seismic slip—but offset channels are formed by the interplay of tectonic and geomorphic processes. To constrain offset channel development under known tectonic and geomorphic...
Reitman, Nadine G.; Mueller, Karl J.; Tucker, Gregory E.; Gold, Ryan D.; Briggs, Richard W.; Barnhart, Katherine R. Holocene earthquake history and slip rate of the southern Teton fault, Wyoming, USA
The 72-km-long Teton normal fault bounds the eastern base of the Teton Range in northwestern Wyoming, USA. Although geomorphic surfaces along the fault record latest Pleistocene to Holocene fault movement, the postglacial earthquake history of the fault has remained enigmatic. We excavated a paleoseismic trench at the Buffalo Bowl site along the...
Duross, Christopher; Gold, Ryan D.; Briggs, Richard W.; Delano, Jaime E.; Ostenaa, Dean A.; Zellman, Mark; Cholewinski, Nicole; Wittke, Seth; Mahan, Shannon A. Variable normal-fault rupture behavior, northern Lost River fault zone, Idaho, USA
The 1983 Mw 6.9 Borah Peak earthquake generated ∼36 km of surface rupture along the Thousand Springs and Warm Springs sections of the Lost River fault zone (LRFZ, Idaho, USA). Although the rupture is a well-studied example of multisegment surface faulting, ambiguity remains regarding the degree to which a bedrock ridge and branch fault at the...
Duross, Christopher; Bunds, Michael P.; Gold, Ryan D.; Briggs, Richard W.; Reitman, Nadine G.; Personius, Stephen; Toké, Nathan A. Surface rupture and distributed deformation revealed by optical satellite imagery: The intraplate 2016 Mw 6.0 Petermann Ranges earthquake, Australia
High-resolution optical satellite imagery is used to quantify vertical surface deformation associated with the intraplate 20 May 2016 Mw 6.0 Petermann Ranges earthquake, Northern Territory, Australia. The 21 ╓ 1 km long NW-trending rupture resulted from reverse motion on a northeast-dipping fault. Vertical surface offsets of up to 0.7 ╓ 0.1 m...
Gold, Ryan D.; Clark, Dan; Barnhart, William D.; King, Tamarah; Quigley, Mark; Briggs, Richard W. Evidence for frequent, large tsunamis spanning locked and creeping parts of the Aleutian megathrust
At the eastern end of the 1957 Andreanof Islands magnitude-8.6 earthquake rupture, Driftwood Bay (Umnak Island) and Stardust Bay (Sedanka Island) lie along presently locked and creeping parts of the Aleutian megathrust, respectively, based on satellite geodesy onshore. Both bays, located 200-km apart, face the Aleutian trench and harbor coastal...
Witter, Robert C.; Briggs, Richard W.; Engelhart, Simon E.; Gelfenbaum, Guy R.; Koehler, Richard D; Nelson, Alan R.; La Selle, Seanpaul; Corbett, Reide; Wallace, Kristi L. Vertical coseismic offsets from differential high-resolution stereogrammetric DSMs: The 2013 Baluchistan, Pakistan earthquake
The recent proliferation of high-resolution (< 3-m spatial resolution) digital topography datasets opens a spectrum of geodetic applications in differential topography, including the quantification of coseismic vertical displacement fields. Most investigations of coseismic vertical displacements to date rely, in part, on pre- or post-event...
Barnhart, William D.; Gold, Ryan D.; Shea, Hannah N.; Peterson, Katherine E.; Briggs, Richard W.; Harbor, David J.