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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),
Passive seismic data collection was done northwest of the Air Force Research Laboratory (AFRL) at Edwards Air Force Base using the horizontal-to-vertical spectral ratio (HVSR) technique. HVSR surveys were done at 43 locations between May and September 2018 to refine the understanding of the bedrock-alluvial aquifer transition zone downgradient from the AFRL. Specifically, the data were collected to help determine the depth to bedrock. The HVSR method is a passive seismic technique that uses a three-component seismometer to measure the vertical and horizontal components of ambient seismic noise. Seismic noise in the range of ~0.1 to 1 Hertz (Hz) is caused by ocean waves, large regional storms, and tectonic sources....
Categories: Data;
Tags: Antelope-Fremont Valleys,
Boron,
California,
Edwards Air Force Base,
Kern County,
This raster dataset represents approximately 49,581 square kilometers of Simrad EM122 multibeam backscatter-intensity data collected in the Bering Sea during U.S. Geological Survey (USGS) cruise MGL1111 aboard the R/V Marcus G. Langseth. Calibrated backscatter-intensity time-series data were adjusted for range-angle, beam pattern, and power-gain distortions.
This raster dataset represents approximately 49,581 square kilometers of Simrad EM122 multibeam backscatter-intensity data collected in the Bering Sea during U.S. Geological Survey (USGS) cruise MGL1111 aboard the R/V Marcus G. Langseth. Calibrated backscatter-intensity time-series data were adjusted for range-angle, beam pattern, and power-gain distortions.
This raster dataset represents approximately 49,581 square kilometers of Simrad EM122 multibeam backscatter-intensity data collected in the Bering Sea during U.S. Geological Survey (USGS) cruise MGL1111 aboard the R/V Marcus G. Langseth. Calibrated backscatter-intensity time-series data were adjusted for range-angle, beam pattern, and power-gain distortions.
Categories: Data;
Types: Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: Bathymetry and Elevation,
CMHRP,
Coastal and Marine Hazards and Resources Program,
Dutch Harbor,
PCMSC,
This raster dataset represents approximately 69,060 square kilometers of Simrad EM122 multibeam-backscatter data collected in the Gulf of Alaska during U.S. Geological Survey (USGS) cruise MGL1109 aboard the R/V Marcus G. Langseth. The data have been reduced for position, elevation, orientation, water-column sound-speed, and refraction effects.
This raster dataset represents approximately 69,060 square kilometers of Simrad EM122 multibeam-backscatter data collected in the Gulf of Alaska during U.S. Geological Survey (USGS) cruise MGL1109 aboard the R/V Marcus G. Langseth. The data have been reduced for position, elevation, orientation, water-column sound-speed, and refraction effects.
This raster dataset represents approximately 49,581 square kilometers of Simrad EM122 multibeam backscatter-intensity data collected in the Bering Sea during U.S. Geological Survey (USGS) cruise MGL1111 aboard the R/V Marcus G. Langseth. Calibrated backscatter-intensity time-series data were adjusted for range-angle, beam pattern, and power-gain distortions.
The Air Force Research Laboratory (AFRL) is about 7 kilometers southwest of Boron, California, and covers 320 square kilometers of Edwards Air Force Base. The AFRL consists of 12 facilities for testing full-size rocket engines, engine components, and liquid and solid propellants. The historical release of contaminants from rocket test stands, evaporation ponds, burn pits, catch basins, and leaking waste-collection tanks has contaminated groundwater in the AFRL. Groundwater aquifers near the AFRL are mostly restricted to fractured granitic bedrock, but previous studies indicate that groundwater and associated contaminants have moved into alluvium to the north and northwest. The U.S. Geological Survey (USGS) and the...
These processed data and provisional codes were created to investigate seismic velocity changes associated with the collapse of Kīlauea caldera during its 2018 eruption. Primary data (i.e., seismic waveforms) are hosted at the Incorporated Research Institutions for Seismology (IRIS; https://www.iris.edu/) and are ingested by the codes included here to reproduce the data analyzed in Hotovec-Ellis et al., 'Earthquake-derived seismic velocity changes during the 2018 caldera collapse of Kīlauea volcano.' The included code ('cwire' short for Coda Wave Interferometry with Repeating Earthquakes) takes a catalog of earthquakes clustered by waveform similarity (e.g., REDPy, https://github.com/ahotovec/REDPy/) and processes...
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,
In June 2018, U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency (EPA) collected geophysical measurements to help evaluate the suitability of a proposed landfill site for disposing mine-waste materials in Fredericktown, MO. Shear-wave (Vs) refraction surveys were collected to measure the shear-wave velocity of the subsurface, which can be used for estimating the depth to rock with the horizontal-to-vertical spectral ratio (HVSR) passive seismic reconnaissance method. A secondary objective was to determine the depth of interfaces for comparison to the resistivity surveys and frequency domain electromagnetic profiles.
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,
From October 2016 to July 2018, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers and Maine Department of Transportation, collected surface, marine and borehole geophysical surveys to characterize the subsurface materials on land and under the water at a former mine facility in Brooksville, Maine. Three water-based geophysical methods were used to evaluate the geometry and composition of subsurface materials. Continuous seismic profiling (CSP) methods provide the depth to water bottom, and, when sufficient signal penetration can be achieved, delineate the depth to bedrock and subbottom materials. Continuous resistivity profiling (CRP) and frequency domain electromagnetics (FDEM) methods...
This raster dataset represents approximately 49,581 square kilometers of Simrad EM122 multibeam backscatter-intensity data collected in the Bering Sea during U.S. Geological Survey (USGS) cruise MGL1111 aboard the R/V Marcus G. Langseth. Calibrated backscatter-intensity time-series data were adjusted for range-angle, beam pattern, and power-gain distortions.
The horizontal-to-vertical spectral ratio (HVSR) method is a passive seismic technique that uses a three-component seismometer to measure the vertical and horizontal components of ambient seismic noise. Seismic noise in the range of ~0.1 to 1 Hertz (Hz) is caused by ocean waves, large regional storms, and tectonic sources. A resonance frequency (f0) is induced in the unconsolidated when there is a substantial contrast (greater than 2:1) in shear-wave acoustic impedance between the overburden and the bedrock. The f0 is determined from the analysis of the spectral ratio of the horizontal and vertical components of the seismic data. The thickness of the overburden can be related to the f0. In general, lower f0 relates...
The dataset is consisted of travel-time records (SWM_DATA.zip) in SEG2 format recorded using multi-station MASW and AM arrays near 10 seismographic stations located in California. A table in the spreadsheet (SWM_deployment_record.xlsx) summarizes the data collection, with multiple sheets providing further details about array configurations at each station. Stations included in the dataset are CE.25091, CE.25392, CI.MAG, CI.NEE2, CI.SNR, GF.99, NC.JECB, NC.JPSB, NP.1797, and JP.1865.
Categories: Data;
Tags: California,
Geophysics,
Seismology,
USGS Science Data Catalog (SDC),
seismic methods
This raster dataset represents approximately 69,060 square kilometers of Simrad EM122 multibeam-backscatter data collected in the Gulf of Alaska during U.S. Geological Survey (USGS) cruise MGL1109 aboard the R/V Marcus G. Langseth. The data have been reduced for position, elevation, orientation, water-column sound-speed, and refraction effects.
This raster dataset represents approximately 49,581 square kilometers of Simrad EM122 multibeam backscatter-intensity data collected in the Bering Sea during U.S. Geological Survey (USGS) cruise MGL1111 aboard the R/V Marcus G. Langseth. Calibrated backscatter-intensity time-series data were adjusted for range-angle, beam pattern, and power-gain distortions.
In May 2017 and July 2018, continuous seismic profiling (CSP) surveys were collected in Goose Pond at the Callahan Mine site. The chirp frequency CSP tool was used in the deep water. A tuned transducer (dual-echo sounder) was used in the shallow water, and the data are served separately but within this data release (See CSP-DSO). CSP methods use an acoustic sound source that travels through the water column, reflects off the bottom and sub-bottom layers and is received at the transducer. Using a water column velocity, the two-way travel time can be converted to distance. CSP methods provide the depth to water bottom, and when sufficient signal penetration can be achieved, CSP can be used to delineate the depth and...
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