Hello. I am a geophysicist with the United States Geological Survey, specializing in active-source, land-based seismology. I use a variety of techniques such as refraction tomography, reflection imaging, Vp/Vs measurements, and guided wave data to locate faults in the near subsurface.
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Filter Total Items: 17
Three-component nodal recordings of aftershocks from the 15 May 2020 Mw 6.5 Monte Cristo, Nevada earthquake
In May of 2020, the U.S. Geological Survey responded to the M6.5 Monte Cristo Range Earthquake, occurring near Tonopah, Nevada: https://www.usgs.gov/news/featured-story/m65-monte-cristo-range-earthquake. 60 DTCC SmartSolo 3-component nodal seismograph systems ("nodes") were deployed in the area and continuously recorded seismic data for about a month. Nodes were deployed in various arrays includin
High-resolution seismic imaging data acquired in 2021 across a trace of the San Andreas Fault at Mee Ranch, Monterey County, California
In April of 2021, the U.S. Geological Survey conducted a high-resolution seismic survey at Mee Ranch in Monterey County, California. Both passive- and active-source seismic data were acquired using DTCC SmartSolo 3-component nodal seismograph systems ("nodes"), which continuously recorded data at rates up to 2000 samples per second. For passive-source acquisition, a 6x5 grid of nodes was deployed
High-resolution seismic imaging data acquired in 2021 across the West Winters Fault, Great Valley Fault System at Bigelow Hills, Yolo County, California
In June of 2021, the U.S. Geological Survey conducted a high-resolution seismic survey at Winters, California. Seismic data were acquired using a DTCC SmartSolo 3-component nodal seismograph system ("node"), which continuously recorded at 2000 samples per second. Nodes were deployed 5 meters apart from west-southwest to east-northeast to create an approximately 800-m-long linear profile. P-wave da
High-resolution seismic data acquired near seismic station CE.57213 in Fremont, California
In September 2021, the U.S. Geological Survey acquired high-resolution P- and S-wave data near seismic station CE.57213 in Fremont, California, approximately 100 m east of the mapped trace of the Hayward Fault. We acquired the seismic data to evaluate the time-averaged shear-wave velocity in the upper 30 m (VS30) and to better understand ground-shaking near the station CE.57213. The seismic data w
High-resolution seismic data acquired at northern Ano Nuevo, California
The U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the Frijoles Fault strand of the San Gregorio Fault Zone (SGFZ) at northern Ano Nuevo, California in 2012. SGFZ is a right-lateral fault system that is mainly offshore, and prior studies provide highly variable slip estimates, which indicates uncertainty about the seismic hazard it poses. Therefore, the primary g
High-resolution seismic data acquired at six Southern California Seismic Network (SCSN) recording stations in 2017
In August 2017, the U.S. Geological Survey acquired high-resolution P- and S-wave seismic data near six Southern California Seismic Network (SCSN) recording stations in southern California: CI.OLI Olinda; CI.SRN Serrano; CI.MUR Murrieta; CI.LCG La Cienega; CI.RUS Rush; and CI.STC Santa Clara (Figure 1). These strong-motion recording stations are located inside Southern California Edison electrical
High-resolution seismic data acquired at six seismic network recording stations in San Bernardino County, California in 2019
In May 2019, the U.S. Geological Survey acquired high resolution P- and S-wave seismic data near six seismic network recording stations in San Bernardino County, California: Southern California Seismic Network CI.CLT Calelectic, CI.MLS Mira Loma, CI.CJM Cajon Mountain and CI.HLN Highland; California Strong Motion Instrumentation Program station CE.23542; and US National Strong-Motion Network stati
Data Release for a 2020 High-Resolution Seismic Survey across Northeastern Edwards Air Force Base, Kern County, California
In June of 2020, the U.S. Geological Survey conducted a high-resolution seismic survey at Edwards Air Force Base in Kern County, California. Seismic data were acquired using a DTCC SmartSolo 3-component nodal seismometer system ("node"), which continuously recorded at 2000 samples per second. Nodes were deployed 5 meters apart along a southwest-northeast trend to create an approximately 3-km-long
Data Release for the 2016 East Bay Seismic Imaging Investigation of the Hayward Fault Zone
In October 2016, we acquired an approximately 15-km-long seismic profile along a linear transect across the East Bay region of the San Francisco Bay area. Our goal was to image previously unknown strands of the Hayward Fault zone and to better delineate the structure and geometry of the main trace of the Hayward Fault. Our profile started near the southern border of San Leandro, California at the
Data Release for the 2018 U.S. Geological Survey - California Geological Survey Fault-Imaging Surveys Across the Hollywood and Santa Monica Faults, Los Angeles County, California
We acquired multiple types of controlled-source seismic data across the Hollywood Fault in Hollywood, Calif., and the Santa Monica Fault in Beverly Hills, Calif., in May and June of 2018. We acquired two separate profiles across the Hollywood Fault, and from those data we can evaluate multiple seismic datasets and calculate seismic models including guided-wave data, tomographic VP data, tomographi
Data report for line 8 of the 2011 USGS seismic imaging survey at San Andreas Lake, San Mateo County, California
In June of 2011, the U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the mapped (Schussler, 1906) trace of the San Andreas Fault zone at San Andreas Lake in unincorporated San Mateo County, California. Our seismic survey consisted of seismic reflection, refraction, and guided-wave data along a 60-m-long profile. To acquire the reflection and refraction data we co-
Data Report for Nodal Seismograph Recording at the Byerly Seismographic Vault, University of California, Berkeley, California
In September and October 2019, the USGS and UC Berkeley (UCB) deployed two nodal seismographs at the Byerly Seismographic Vault (station BRK), east of the UCB campus. One of the nodes was located immediately outside the vault, and the other was located within the vault, adjacent to a broadband seismometer. The objective of this deployment was to compare recordings of local earthquakes and ambient
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Seismic images and subsurface structures of northeastern Edwards Air Force Base, Kern County, California
We used multi-component seismic data (including two-dimensional images of compressional-wave velocity [vP], shear-wave velocity [vS], the ratio of compressional-wave velocity to shear-wave velocity [vP/vS ratio], Poisson’s ratio [μ], and seismic reflections) along a transect across northeastern Edwards Air Force Base to investigate the upper few hundred meters of the subsurface. The shallow subsur
Authors
Rufus D. Catchings, Mark R. Goldman, Joanne H. Chan, Robert R. Sickler, Coyn J. Criley
Evidence of active Quaternary deformation on the Great Valley fault system near Winters, northern California
The Great Valley fault system defines the tectonic boundary between the Coast Ranges and the Central Valley in California, is active throughout the Quaternary, and has been the source of several significant (M > 6) historic earthquakes, including the 1983 M 6.5 Coalinga earthquake and the 1892 Vacaville–Winters earthquake sequence. However, the locations and geometries of individual faults in the
Authors
Charles Cashman Trexler, Alexander E. Morelan, Rufus D. Catchings, Mark Goldman, Jack Willard
2018 U.S. Geological Survey–California Geological Survey fault-imaging surveys across the Hollywood and Santa Monica Faults, Los Angeles County, California
We acquired multiple types of seismic data across the Hollywood Fault in Hollywood, Calif., and the Santa Monica Fault in Beverly Hills, Calif., in May and June 2018. On the basis of our data, we infer near-surface locations of various traces of these faults.From two separate profiles across the Hollywood Fault, we evaluated multiple seismic datasets and models, including guided-wave data, tomogra
Authors
Rufus D. Catchings, Janis Hernandez, Mark R. Goldman, Joanne H. Chan, Robert R. Sickler, Brian Olson, Coyn J. Criley
Mechanics of near-field deformation during co- and post-seismic shallow fault slip
Poor knowledge of how faults slip and distribute deformation in the shallow crust hinders efforts to mitigate hazards where faults increasingly intersect with the expanding global population at Earth’s surface. Here we analyze two study sites along the 2014 M 6.0 South Napa, California, earthquake rupture, each dominated by either co- or post-seismic shallow fault slip. We combine mobile laser sca
Authors
Johanna Nevitt, Benjamin A. Brooks, Rufus D. Catchings, Mark Goldman, Todd Ericksen, Craig L. Glennie
Three-dimensional basin and fault structure from a detailed seismic velocity model of Coachella Valley, Southern California
The Coachella Valley in the northern Salton Trough is known to produce destructive earthquakes, making it a high seismic hazard area. Knowledge of the seismic velocity structure and geometry of the sedimentary basins and fault zones is required to improve earthquake hazard estimates in this region. We simultaneously inverted first P wave travel times from the Southern California Seismic Network (3
Authors
Rasheed Ajala, Patricia Persaud, Joann M. Stock, Gary S. Fuis, John A. Hole, Mark Goldman, Daniel Scheirer
Two-dimensional seismic velocities and structural variations at three British Columbia Hydro and Power Authority (BC Hydro) dam sites, Vancouver Island, British Columbia, Canada
SummaryIn June, 2017, we acquired seismic data along five linear profiles at three British Columbia Hydro and Power Authority (BC Hydro, a Canadian provincial Crown Corporation) dam sites (John Hart, Ladore, and Strathcona Dams) on Vancouver Island, British Columbia, Canada. We also attempted to acquire linear seismic profiles at two additional BC Hydro dam sites (Ruskin Dam and Stave Falls Dam) e
Authors
Rufus D. Catchings, Kofi O. Addo, Mark R. Goldman, Joanne H. Chan, Robert R. Sickler, Coyn J. Criley
Seismic evaluation of shallow-depth structure, faulting, and groundwater variations across the Dos Palmas Preserve, Riverside County, California
IntroductionDos Palmas Preserve is a Colorado Desert oasis and wetland in Riverside County, California, located near the base of the Orocopia Mountains and northeast of the Salton Sea. The original source of water for the oasis was artesian springs that developed at the base of the Orocopia Mountains, but more abundant water supplies were later provided to Dos Palmas Preserve when the Coachella Ca
Authors
Rufus D. Catchings, Mark R. Goldman, Joanne H. Chan, Robert R. Sickler, Michael J. Rymer, Coyn J. Criley
VS30 at three strong-motion recording stations in Napa and Napa County, California — Main Street in downtown Napa, Napa fire station number 3, and Kreuzer Lane — Calculations determined from s-wave refraction tomography and multichannel analysis of surfac
The August 24, 2014, moment magnitude (Mw) 6.0 South Napa earthquake caused an estimated $400 million in structural damage to the City of Napa, California. In 2015, we acquired high-resolution P- and S-wave seismic data near three strong-motion recording stations in Napa County where high peak ground accelerations (PGAs) were recorded during the South Napa earthquake. In this report, we present re
Authors
Joanne H. Chan, Rufus D. Catchings, Mark R. Goldman, Coyn J. Criley
VS30 at three strong-motion recording stations in Napa and Solano Counties, California — Lovall Valley Road, Broadway Street and Sereno Drive in Vallejo, and Vallejo Fire Station — Calculations determined from S-wave refraction tomography and multichannel
The August 24, 2014, moment magnitude (Mw) 6.0 South Napa earthquake caused an estimated $400 million in structural damage to the City of Napa, California. In 2015, we acquired high-resolution P- and S-wave seismic data near three strong-motion recording stations in Napa and Solano Counties where high peak ground accelerations (PGAs) were recorded during the South Napa earthquake. In this report,
Authors
Joanne H. Chan, Rufus D. Catchings, Mark R. Goldman, Coyn J. Criley
Subsurface geometry of the San Andreas fault in southern California: Results from the Salton Seismic Imaging Project (SSIP) and strong ground motion expectations
The San Andreas fault (SAF) is one of the most studied strike‐slip faults in the world; yet its subsurface geometry is still uncertain in most locations. The Salton Seismic Imaging Project (SSIP) was undertaken to image the structure surrounding the SAF and also its subsurface geometry. We present SSIP studies at two locations in the Coachella Valley of the northern Salton trough. On our line 4, a
Authors
Gary S. Fuis, Klaus Bauer, Mark R. Goldman, Trond Ryberg, Victoria E. Langenheim, Daniel S. Scheirer, Michael J. Rymer, Joann M. Stock, John A. Hole, Rufus D. Catchings, Robert Graves, Brad T. Aagaard
Shallow-depth location and geometry of the Piedmont Reverse splay of the Hayward Fault, Oakland, California
The Piedmont Thrust Fault, herein referred to as the Piedmont Reverse Fault (PRF), is a splay of the Hayward Fault that trends through a highly populated area of the City of Oakland, California (fig. 1A). Although the PRF is unlikely to generate a large-magnitude earthquake, slip on the PRF or high-amplitude seismic energy traveling along the PRF may cause considerable damage during a large earthq
Authors
Rufus D. Catchings, Mark R. Goldman, David Trench, Michael Buga, Joanne H. Chan, Coyn J. Criley, Luther M. Strayer
Continuity of the West Napa–Franklin fault zone inferred from guided waves generated by earthquakes following the 24 August 2014 Mw 6.0 South Napa Earthquake
We measure peak ground velocities from fault‐zone guided waves (FZGWs), generated by on‐fault earthquakes associated with the 24 August 2014 Mw 6.0 South Napa earthquake. The data were recorded on three arrays deployed across north and south of the 2014 surface rupture. The observed FZGWs indicate that the West Napa fault zone (WNFZ) and the Franklin fault (FF) are continuous in the subsurface for
Authors
Rufus D. Catchings, Mark R. Goldman, Y.-G. Li, Joanne H. Chan
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Three-component nodal recordings of aftershocks from the 15 May 2020 Mw 6.5 Monte Cristo, Nevada earthquake
In May of 2020, the U.S. Geological Survey responded to the M6.5 Monte Cristo Range Earthquake, occurring near Tonopah, Nevada: https://www.usgs.gov/news/featured-story/m65-monte-cristo-range-earthquake. 60 DTCC SmartSolo 3-component nodal seismograph systems ("nodes") were deployed in the area and continuously recorded seismic data for about a month. Nodes were deployed in various arrays includinHigh-resolution seismic imaging data acquired in 2021 across a trace of the San Andreas Fault at Mee Ranch, Monterey County, California
In April of 2021, the U.S. Geological Survey conducted a high-resolution seismic survey at Mee Ranch in Monterey County, California. Both passive- and active-source seismic data were acquired using DTCC SmartSolo 3-component nodal seismograph systems ("nodes"), which continuously recorded data at rates up to 2000 samples per second. For passive-source acquisition, a 6x5 grid of nodes was deployedHigh-resolution seismic imaging data acquired in 2021 across the West Winters Fault, Great Valley Fault System at Bigelow Hills, Yolo County, California
In June of 2021, the U.S. Geological Survey conducted a high-resolution seismic survey at Winters, California. Seismic data were acquired using a DTCC SmartSolo 3-component nodal seismograph system ("node"), which continuously recorded at 2000 samples per second. Nodes were deployed 5 meters apart from west-southwest to east-northeast to create an approximately 800-m-long linear profile. P-wave daHigh-resolution seismic data acquired near seismic station CE.57213 in Fremont, California
In September 2021, the U.S. Geological Survey acquired high-resolution P- and S-wave data near seismic station CE.57213 in Fremont, California, approximately 100 m east of the mapped trace of the Hayward Fault. We acquired the seismic data to evaluate the time-averaged shear-wave velocity in the upper 30 m (VS30) and to better understand ground-shaking near the station CE.57213. The seismic data wHigh-resolution seismic data acquired at northern Ano Nuevo, California
The U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the Frijoles Fault strand of the San Gregorio Fault Zone (SGFZ) at northern Ano Nuevo, California in 2012. SGFZ is a right-lateral fault system that is mainly offshore, and prior studies provide highly variable slip estimates, which indicates uncertainty about the seismic hazard it poses. Therefore, the primary gHigh-resolution seismic data acquired at six Southern California Seismic Network (SCSN) recording stations in 2017
In August 2017, the U.S. Geological Survey acquired high-resolution P- and S-wave seismic data near six Southern California Seismic Network (SCSN) recording stations in southern California: CI.OLI Olinda; CI.SRN Serrano; CI.MUR Murrieta; CI.LCG La Cienega; CI.RUS Rush; and CI.STC Santa Clara (Figure 1). These strong-motion recording stations are located inside Southern California Edison electricalHigh-resolution seismic data acquired at six seismic network recording stations in San Bernardino County, California in 2019
In May 2019, the U.S. Geological Survey acquired high resolution P- and S-wave seismic data near six seismic network recording stations in San Bernardino County, California: Southern California Seismic Network CI.CLT Calelectic, CI.MLS Mira Loma, CI.CJM Cajon Mountain and CI.HLN Highland; California Strong Motion Instrumentation Program station CE.23542; and US National Strong-Motion Network statiData Release for a 2020 High-Resolution Seismic Survey across Northeastern Edwards Air Force Base, Kern County, California
In June of 2020, the U.S. Geological Survey conducted a high-resolution seismic survey at Edwards Air Force Base in Kern County, California. Seismic data were acquired using a DTCC SmartSolo 3-component nodal seismometer system ("node"), which continuously recorded at 2000 samples per second. Nodes were deployed 5 meters apart along a southwest-northeast trend to create an approximately 3-km-longData Release for the 2016 East Bay Seismic Imaging Investigation of the Hayward Fault Zone
In October 2016, we acquired an approximately 15-km-long seismic profile along a linear transect across the East Bay region of the San Francisco Bay area. Our goal was to image previously unknown strands of the Hayward Fault zone and to better delineate the structure and geometry of the main trace of the Hayward Fault. Our profile started near the southern border of San Leandro, California at theData Release for the 2018 U.S. Geological Survey - California Geological Survey Fault-Imaging Surveys Across the Hollywood and Santa Monica Faults, Los Angeles County, California
We acquired multiple types of controlled-source seismic data across the Hollywood Fault in Hollywood, Calif., and the Santa Monica Fault in Beverly Hills, Calif., in May and June of 2018. We acquired two separate profiles across the Hollywood Fault, and from those data we can evaluate multiple seismic datasets and calculate seismic models including guided-wave data, tomographic VP data, tomographiData report for line 8 of the 2011 USGS seismic imaging survey at San Andreas Lake, San Mateo County, California
In June of 2011, the U.S. Geological Survey acquired high-resolution P- and S-wave seismic data across the mapped (Schussler, 1906) trace of the San Andreas Fault zone at San Andreas Lake in unincorporated San Mateo County, California. Our seismic survey consisted of seismic reflection, refraction, and guided-wave data along a 60-m-long profile. To acquire the reflection and refraction data we co-Data Report for Nodal Seismograph Recording at the Byerly Seismographic Vault, University of California, Berkeley, California
In September and October 2019, the USGS and UC Berkeley (UCB) deployed two nodal seismographs at the Byerly Seismographic Vault (station BRK), east of the UCB campus. One of the nodes was located immediately outside the vault, and the other was located within the vault, adjacent to a broadband seismometer. The objective of this deployment was to compare recordings of local earthquakes and ambient - Publications
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Seismic images and subsurface structures of northeastern Edwards Air Force Base, Kern County, California
We used multi-component seismic data (including two-dimensional images of compressional-wave velocity [vP], shear-wave velocity [vS], the ratio of compressional-wave velocity to shear-wave velocity [vP/vS ratio], Poisson’s ratio [μ], and seismic reflections) along a transect across northeastern Edwards Air Force Base to investigate the upper few hundred meters of the subsurface. The shallow subsurAuthorsRufus D. Catchings, Mark R. Goldman, Joanne H. Chan, Robert R. Sickler, Coyn J. CrileyEvidence of active Quaternary deformation on the Great Valley fault system near Winters, northern California
The Great Valley fault system defines the tectonic boundary between the Coast Ranges and the Central Valley in California, is active throughout the Quaternary, and has been the source of several significant (M > 6) historic earthquakes, including the 1983 M 6.5 Coalinga earthquake and the 1892 Vacaville–Winters earthquake sequence. However, the locations and geometries of individual faults in theAuthorsCharles Cashman Trexler, Alexander E. Morelan, Rufus D. Catchings, Mark Goldman, Jack Willard2018 U.S. Geological Survey–California Geological Survey fault-imaging surveys across the Hollywood and Santa Monica Faults, Los Angeles County, California
We acquired multiple types of seismic data across the Hollywood Fault in Hollywood, Calif., and the Santa Monica Fault in Beverly Hills, Calif., in May and June 2018. On the basis of our data, we infer near-surface locations of various traces of these faults.From two separate profiles across the Hollywood Fault, we evaluated multiple seismic datasets and models, including guided-wave data, tomograAuthorsRufus D. Catchings, Janis Hernandez, Mark R. Goldman, Joanne H. Chan, Robert R. Sickler, Brian Olson, Coyn J. CrileyMechanics of near-field deformation during co- and post-seismic shallow fault slip
Poor knowledge of how faults slip and distribute deformation in the shallow crust hinders efforts to mitigate hazards where faults increasingly intersect with the expanding global population at Earth’s surface. Here we analyze two study sites along the 2014 M 6.0 South Napa, California, earthquake rupture, each dominated by either co- or post-seismic shallow fault slip. We combine mobile laser scaAuthorsJohanna Nevitt, Benjamin A. Brooks, Rufus D. Catchings, Mark Goldman, Todd Ericksen, Craig L. GlennieThree-dimensional basin and fault structure from a detailed seismic velocity model of Coachella Valley, Southern California
The Coachella Valley in the northern Salton Trough is known to produce destructive earthquakes, making it a high seismic hazard area. Knowledge of the seismic velocity structure and geometry of the sedimentary basins and fault zones is required to improve earthquake hazard estimates in this region. We simultaneously inverted first P wave travel times from the Southern California Seismic Network (3AuthorsRasheed Ajala, Patricia Persaud, Joann M. Stock, Gary S. Fuis, John A. Hole, Mark Goldman, Daniel ScheirerTwo-dimensional seismic velocities and structural variations at three British Columbia Hydro and Power Authority (BC Hydro) dam sites, Vancouver Island, British Columbia, Canada
SummaryIn June, 2017, we acquired seismic data along five linear profiles at three British Columbia Hydro and Power Authority (BC Hydro, a Canadian provincial Crown Corporation) dam sites (John Hart, Ladore, and Strathcona Dams) on Vancouver Island, British Columbia, Canada. We also attempted to acquire linear seismic profiles at two additional BC Hydro dam sites (Ruskin Dam and Stave Falls Dam) eAuthorsRufus D. Catchings, Kofi O. Addo, Mark R. Goldman, Joanne H. Chan, Robert R. Sickler, Coyn J. CrileySeismic evaluation of shallow-depth structure, faulting, and groundwater variations across the Dos Palmas Preserve, Riverside County, California
IntroductionDos Palmas Preserve is a Colorado Desert oasis and wetland in Riverside County, California, located near the base of the Orocopia Mountains and northeast of the Salton Sea. The original source of water for the oasis was artesian springs that developed at the base of the Orocopia Mountains, but more abundant water supplies were later provided to Dos Palmas Preserve when the Coachella CaAuthorsRufus D. Catchings, Mark R. Goldman, Joanne H. Chan, Robert R. Sickler, Michael J. Rymer, Coyn J. CrileyVS30 at three strong-motion recording stations in Napa and Napa County, California — Main Street in downtown Napa, Napa fire station number 3, and Kreuzer Lane — Calculations determined from s-wave refraction tomography and multichannel analysis of surfac
The August 24, 2014, moment magnitude (Mw) 6.0 South Napa earthquake caused an estimated $400 million in structural damage to the City of Napa, California. In 2015, we acquired high-resolution P- and S-wave seismic data near three strong-motion recording stations in Napa County where high peak ground accelerations (PGAs) were recorded during the South Napa earthquake. In this report, we present reAuthorsJoanne H. Chan, Rufus D. Catchings, Mark R. Goldman, Coyn J. CrileyVS30 at three strong-motion recording stations in Napa and Solano Counties, California — Lovall Valley Road, Broadway Street and Sereno Drive in Vallejo, and Vallejo Fire Station — Calculations determined from S-wave refraction tomography and multichannel
The August 24, 2014, moment magnitude (Mw) 6.0 South Napa earthquake caused an estimated $400 million in structural damage to the City of Napa, California. In 2015, we acquired high-resolution P- and S-wave seismic data near three strong-motion recording stations in Napa and Solano Counties where high peak ground accelerations (PGAs) were recorded during the South Napa earthquake. In this report,AuthorsJoanne H. Chan, Rufus D. Catchings, Mark R. Goldman, Coyn J. CrileySubsurface geometry of the San Andreas fault in southern California: Results from the Salton Seismic Imaging Project (SSIP) and strong ground motion expectations
The San Andreas fault (SAF) is one of the most studied strike‐slip faults in the world; yet its subsurface geometry is still uncertain in most locations. The Salton Seismic Imaging Project (SSIP) was undertaken to image the structure surrounding the SAF and also its subsurface geometry. We present SSIP studies at two locations in the Coachella Valley of the northern Salton trough. On our line 4, aAuthorsGary S. Fuis, Klaus Bauer, Mark R. Goldman, Trond Ryberg, Victoria E. Langenheim, Daniel S. Scheirer, Michael J. Rymer, Joann M. Stock, John A. Hole, Rufus D. Catchings, Robert Graves, Brad T. AagaardShallow-depth location and geometry of the Piedmont Reverse splay of the Hayward Fault, Oakland, California
The Piedmont Thrust Fault, herein referred to as the Piedmont Reverse Fault (PRF), is a splay of the Hayward Fault that trends through a highly populated area of the City of Oakland, California (fig. 1A). Although the PRF is unlikely to generate a large-magnitude earthquake, slip on the PRF or high-amplitude seismic energy traveling along the PRF may cause considerable damage during a large earthqAuthorsRufus D. Catchings, Mark R. Goldman, David Trench, Michael Buga, Joanne H. Chan, Coyn J. Criley, Luther M. StrayerContinuity of the West Napa–Franklin fault zone inferred from guided waves generated by earthquakes following the 24 August 2014 Mw 6.0 South Napa Earthquake
We measure peak ground velocities from fault‐zone guided waves (FZGWs), generated by on‐fault earthquakes associated with the 24 August 2014 Mw 6.0 South Napa earthquake. The data were recorded on three arrays deployed across north and south of the 2014 surface rupture. The observed FZGWs indicate that the West Napa fault zone (WNFZ) and the Franklin fault (FF) are continuous in the subsurface forAuthorsRufus D. Catchings, Mark R. Goldman, Y.-G. Li, Joanne H. Chan