Mark R Goldman

2015 high resolution seismic acquisition at Dos Palmas Preserve, Mecca, California

In March 2015, the U.S. Geological Survey acquired seismic reflection and refraction data along an approximately 2.8-km-long profile across northwest-trending San Andreas Fault splays located at the Dos Palmas Preserve east of Salton Sea. To acquire the reflection and refraction data, we collocated shots and geophones, spaced every 3 m along the profile. We used 933 SercelTM L40A P-wave (40-Hz vertical-component) geophones with a sensitivity of 22.34 volts/meter/second to record 925 P-wave shots. We generated P-wave data using one of two active sources: 400-grain Betsy-SeisgunTM shots at approximately every 90 m and a 3.5-kg sledgehammer and steel plate combination at every 3 m between the seisgun shots. All data...

Categories: Data; Tags: Dos Palmas Spring, Geophysics, Mecca, Salton Sea, Seismology, All tags... Structural Geology, USGS Science Data Catalog (SDC), Water Resources, earthquake hazards, faulting (geologic), groundwater, groundwater flow, seismic reflection methods, seismic refraction methods, seismology, Fewer tags

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 San Francisco Bay shoreline, trended ENE through the northern edge of Castro Valley, California, and ended approximately 5 km WSW of San Ramon, California. The data were analyzed using refraction tomography modeling, reflection processing, and guided-wave analysis. The analyzed data are presented in separate reports by...

Categories: Data; Tags: Geophysics, Hayward, San Francisco Bay Area, Seismology, USGS Science Data Catalog (SDC), All tags... earthquakes, faulting (geologic), hazards, seismic methods, seismic reflection methods, seismic refraction methods, seismology, Fewer tags

2017 seismic imaging of the West Napa Fault Zone, St. Helena, California

In April 2017, the U.S. Geological Survey acquired high resolution P- and S-wave seismic data across the suspected trace of the West Napa Fault zone in St. Helena, California. We acquired seismic reflection, refraction, and guided-wave data along a 215-m-long profile across the expected trend of the West Napa Fault zone. To acquire the reflection and refraction data, we co-located shots and geophones, spaced every 2 m along the profile. We used 109 SercelTM L40A P-wave (40-Hz vertical-component) geophones with a sensitivity of 22.34 volts/meter/second to record 108 P-wave shots, and 109 SercelTM L28-LBH S-wave (4.5-Hz horizontal-component) geophones with a sensitivity of 31.3 volts/meter/second to record 108 S-wave...

Categories: Data; Tags: Geophysics, Saint Helena, Seismology, USGS Science Data Catalog (SDC), earthquakes, All tags... faulting (geologic), hazards, seismic reflection methods, seismic refraction methods, seismology, Fewer tags

High-resolution seismic data acquired at northern Año 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 Año 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 goal of the seismic survey was to better understand the structure and geometry of the onshore section of the Frijoles Fault strand of the SGFZ. We deployed 118 geophones (channels) at 5-m spacing along a linear profile centered on the mapped surface trace of the Frijoles Fault and co-located active P- and S-wave sources...

Categories: Data; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Ano Nuevo, California, Central California Coastal, Geophysics, Seismology, All tags... USGS Science Data Catalog (SDC), earthquake zone, earthquakes, fault, fault zones, geoscientificInformation, hazards, seismic methods, seismic refraction methods, tomography, Fewer tags

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, including guided-wave data, tomographic Vp data, and tomographic Vs data. From the datasets, we can calculate multiple seismic models, including Vp/Vs and Poisson's ratio models derived from tomographic Vp and Vs data, Rayleigh-wave-based Vs models, Love-wave-based Vs models, Vp/Vs and Poisson's ratio models (derived from combinations of tomographic-based Vp and surface-wave-based Vs models), P-wave reflection...

Categories: Data; Tags: Beverly Hills, Hollywood, Seismology, USGS Science Data Catalog (SDC), earthquakes, All tags... faulting (geologic), hazards, seismic methods, seismic refraction methods, seismology, Fewer tags