Map
of California & Nevada earthquakes
FARB - Farallon Islands, CA, USA
Site of FARB vault |
1997/03/15 00:00:00 - Present
Latitude: 37.6978
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Aerial photograph of island |
Location |
Geology |
Vault Conditions
Instrumentation |
Network |
Operation Notes
Noise Characteristics |
Data Availability
- Location:
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Site is located on the
Farallon National
Wildlife Refuge, offshore of San Francisco, and is under the auspices of
the US Fish and Wildlife Service.
This is a particularly tricky site for maintenance, since access to
the Island is limited. This site experiences loss of power from
time to time, due to problems with the island generator. Despite
the 15 batteries, there are periods of time when the station is
down due to loss of power. This site also experiences occasional problems due
to corrosion of cables.
- Geology:
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Granite
- Vault/Borehole conditions:
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The sensors are installed in a near-surface
vault and covered with rocks and foam
in order to provide thermal stability.
- Instrumentation:
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Sensor Datalogger Start Date End Date SEED Channels Location Battery Voltage Q4120 2001/06/01 Present LE?,UE? FBA Voltage Q4120 2001/06/01 2004/08/19 LF?,UF? Guralp CMG-3 Broad Band Seismometer Q4120 2001/03/12 2004/08/19 BH?,HH?,LH?,VH? Guralp CMG-3 Broad Band Seismometer Q4120 2001/06/01 2004/08/19 UM? Guralp CMG-40T Triaxial Seismometer Q4120 1997/03/15 2001/03/12 HH?,LH?,VH?,UH?,BH? Internal Temperature Q4120 2004/08/19 Present UK? Kinemetrics FBA ES-T Accel. (2 g max 10 v/g) Q4120 2004/08/19 Present HL?,LL?,BL? Kinemetrics FBA-23 Accel. (2 g max 1.25 v/g) Q4120 1997/03/15 2004/08/19 LL?,BL?,HL? Motorola MPX201 Pressure Q4120 1997/03/15 Present LD? Solar Insolation Q4120 2001/06/01 2004/08/19 UE?,LE? Streckeisen STS-2 VBB Tri-Axial Seismometer Q4120 2004/08/19 Present LH?,HH?,UM?,BH?,VH?,UH? YSI 44031 Thermistor Q4120 1997/03/15 Present LK? The FARB site also is home to a continuously operating GPS receiver as part of the BARD network.
- Network:
-
BK (Berkeley Digital Seismic Network)
- Operation Notes: (may not be current)
- This section summarizes major changes in equipment or in instrumentation at FARB.
- 06/15/2004: Sampling rate of BH channels changed from 20 Hz to 40 Hz.
- 07/01/2003: HH channels modified to have casual filters.
- 03/13/2001: Broadband sensor replaced due to increase in baseline noise level.
- 04/07/2000: Replaced GPS clock
- 03/06/2000: Modified MSHEAR configuration
- 12/16/1999: Q4120 software upgraded to MSHEAR
- 09/21/1998: Replaced baraometric sensor to solved problems dating from 04/18/1998.
- 03/14/1998: Installed 4 GB disk on Q4120
- 03/15/1997: Seismic instrumentation installed: Quanterra Q4120 Datalogger, Guralp CMG-40T seismometer, Kinemetrics FBA-23 accelerometer. Vanguard 300 FRAD used for frame relay.
- 01/27/1994: BARD GPS monument and Ashtech receiver installed.
- Noise Characteristics:
-
The figures below are cumulative plots of power spectral density (psd)
determined from the broadband channels. In each figure, the vertical
component psd is plotted with blue diamonds, the north component
psd with red squares, and the east component psd with green circles.
The results are presented in the 5 different frequency bands, and
the USGS/Albuquerque low noise model is plotted as a dashed line in each.
The PSD units are in dB (decibel) relative to 1 (m/s**2)**2/Hz. The current
annual plot is updated weekly.
Cumulative PSD results 1999 2000 2001 2002 2003 2004 2005 
- Data Availability:
- BDSN waveforms and associated metadata are available at the
Northern California Earthquake Data Center (NCEDC).
- Map of BDSN stations
- Table of BDSN stations
- BK Information Directory, including
- List of station locations
- List of available channels
- Instrument Response
- Information on Quanterra Timing Errors
- Information on Quanterra 4120 FIR Filter changes - 6/30/2003
- Information on BH sampling rate change - 06/15/2004
- View digital seismograms
Several tools provide access to SEED format data at the NCEDC, both in terms of querying the archives and allowing data requests.- Querying the archives
- Requesting data
Help on using these tools is available.
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Berkeley Seismological Lab
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Copyright 1995-2005, The Regents of the University of California.
Last modified: Wed Jun 25 13:34:08 PDT 2008