Borehole Strainmeter data from California from 1981 to the present
Dates
Publication Date
2015
Start Date
1981
Citation
Malcolm Johnston, G. Doug Myren, Stanley Silverman, and Robert Mueller, 2015, Borehole Strainmeter data from California from 1981 to the present: U.S. Geological Survey: Menlo Park, CA, http://earthquake.usgs.gov/monitoring/deformation/data/download/.
Summary
The data from the borehole strainmeter network set consists of raw data from the telemetry, state of health measurements, environmental measurement of temperature and pressure, and processed borehole strainmeter data. For each strainmeter site in this network, there will be a mix of raw data, SOH, environmental data, and processed strain. Each channel of data consists of a time of observation, usually 10-minute intervals, and a number that is either telemetry counts (which is proportional to the voltage output by the instrument), or in units of strain, which are either in part per million or parts per billion. Processed strain will be free of glitches and other artifacts and are corrected for changes in atmospheric pressure (which [...]
Summary
The data from the borehole strainmeter network set consists of raw data from the telemetry, state of health measurements, environmental measurement of temperature and pressure, and processed borehole strainmeter data. For each strainmeter site in this network, there will be a mix of raw data, SOH, environmental data, and processed strain. Each channel of data consists of a time of observation, usually 10-minute intervals, and a number that is either telemetry counts (which is proportional to the voltage output by the instrument), or in units of strain, which are either in part per million or parts per billion. Processed strain will be free of glitches and other artifacts and are corrected for changes in atmospheric pressure (which is also recorded onsite). The processed strain data are a mix of single component, volumetric measurements and multi-component measurements of horizontal strain converted to dilatation and shear.
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Borehole_Strainmeter_data_from_California_from_1981_to_the_present.xml Original FGDC Metadata
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Purpose
High sensitivity strainmeters have been installed in 100 to 200 meter deep boreholes at approximately 40 sites in California within the San Francisco Bay Area, San Juan Bautista, Parkfield, Southern California, and Long Valley (Mammoth Lakes). These instruments are capable of measuring strain changes at the part per billion level once every 10 minutes. The goal is to measure at the highest possible resolution the accumulation and the release of strain on major earthquake faults in California (San Andreas and Hayward faults), and magmatic intrusion at volcanic centers (Long Valley). Borehole strainmeter measurement compliment other geodetic measurement, primarily GPS and conventional land-survey techniques (primarily electronic distance meter) because of they are 10 to 100 times more sensitive to displacements over intervals of minutes to days.
