2017b high resolution seismic imaging of the West Napa Fault Zone, St. Helena, California
In September 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, approximately 70 m north of the previous seismic survey conducted in April 2017 (Chan et al., 2018). We acquired seismic reflection, refraction, and guided-wave data along a 75-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 1 and 2 m along the profile. We used 77 SercelTM L40A P-wave (40-Hz vertical-component) geophones with a sensitivity of 22.34 volts/meter/second to record 60 P-wave shots, and 77 SercelTM L28-LBH S-wave (4.5-Hz horizontal-component) geophones with a sensitivity of 31.3 volts/meter/second to record 60 S-wave shots. We generated P-wave data using a 3.5-kg sledgehammer and steel plate combination. S-wave sources were generated by horizontally striking an aluminum block with a 3.5-kg sledgehammer. We acquired fault zone guided wave data by generating P-wave (226-kg accelerated weight-drop, AWD) and S-wave (angle AWD) energies approximately 160 m north of the recording arrays. All data were recorded using one 60-channel Geometrics Stratavisor NX-60TM seismograph with a 24-bit analog-to-digital converter (Subcommittee of the SEG Engineering and Groundwater Geophysics Committee, 1990); the seismograph was connected to the P- and S-wave geophones via refraction cables. Each shot was recorded for two seconds, with data recording starting 100 ms before the actual time of the shot. Data were recorded at a sampling rate of 0.5 ms, or 2000 samples per second. This report provides the metadata needed to utilize the seismic data.
Reference:
Subcommittee of the SEG Engineering and Groundwater Geophysics Committee, Pullan,
S. E., Chairman, 1990, Recommended standard for seismic (/radar) data files in the
personal computer environment: Geophysics, vol. 55, no. 9, p. 1260-1271.
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Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | public |
| bureauCode |
[ "010:12" ] |
| contactPoint |
{ "fn": "Joanne H Chan", "@type": "vcard:Contact", "hasEmail": "mailto:jchan@usgs.gov" } |
| description | In September 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, approximately 70 m north of the previous seismic survey conducted in April 2017 (Chan et al., 2018). We acquired seismic reflection, refraction, and guided-wave data along a 75-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 1 and 2 m along the profile. We used 77 SercelTM L40A P-wave (40-Hz vertical-component) geophones with a sensitivity of 22.34 volts/meter/second to record 60 P-wave shots, and 77 SercelTM L28-LBH S-wave (4.5-Hz horizontal-component) geophones with a sensitivity of 31.3 volts/meter/second to record 60 S-wave shots. We generated P-wave data using a 3.5-kg sledgehammer and steel plate combination. S-wave sources were generated by horizontally striking an aluminum block with a 3.5-kg sledgehammer. We acquired fault zone guided wave data by generating P-wave (226-kg accelerated weight-drop, AWD) and S-wave (angle AWD) energies approximately 160 m north of the recording arrays. All data were recorded using one 60-channel Geometrics Stratavisor NX-60TM seismograph with a 24-bit analog-to-digital converter (Subcommittee of the SEG Engineering and Groundwater Geophysics Committee, 1990); the seismograph was connected to the P- and S-wave geophones via refraction cables. Each shot was recorded for two seconds, with data recording starting 100 ms before the actual time of the shot. Data were recorded at a sampling rate of 0.5 ms, or 2000 samples per second. This report provides the metadata needed to utilize the seismic data. Reference: Subcommittee of the SEG Engineering and Groundwater Geophysics Committee, Pullan, S. E., Chairman, 1990, Recommended standard for seismic (/radar) data files in the personal computer environment: Geophysics, vol. 55, no. 9, p. 1260-1271. |
| distribution |
[ { "@type": "dcat:Distribution", "title": "Digital Data", "format": "XML", "accessURL": "https://doi.org/10.5066/P9OC53A4", "mediaType": "application/http", "description": "Landing page for access to the data" }, { "@type": "dcat:Distribution", "title": "Original Metadata", "format": "XML", "mediaType": "text/xml", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.5b6de6c7e4b0f5d57876adac.xml" } ] |
| identifier | http://datainventory.doi.gov/id/dataset/USGS_5b6de6c7e4b0f5d57876adac |
| keyword |
[ "Northern California", "Saint Helena", "USGS:5b6de6c7e4b0f5d57876adac", "earthquake hazards", "earthquakes", "faulting (geologic)", "seismic reflection methods", "seismic refraction methods", "seismology" ] |
| modified | 2020-08-27T00:00:00Z |
| publisher |
{ "name": "U.S. Geological Survey", "@type": "org:Organization" } |
| spatial | -122.497807, 38.537754, -122.496887, 38.537998 |
| theme |
[ "geospatial" ] |
| title | 2017b high resolution seismic imaging of the West Napa Fault Zone, St. Helena, California |
