FARB - Farallon Islands, CA, USA
We operate broadband and borehole stations under the network code BK. The Berkeley Digital Seismic Network (BDSN) is a regional network of very broadband and strong motion seismic stations designed to monitor regional seismic activity as well as provide high quality data. The Berkeley borehole stations have borehole geophones or other seismic sensors and may have other geophysical instrumentation.
BARD is our GPS network for monitoring crustal deformation across the Pacific-North America plate boundary and in the San Francisco Bay Area for earthquake hazard reduction studies and rapid earthquake emergency response assessment
|Station Name||FARB (FARB)|
|In Operation||1997/03/15 00:00:00 - Present|
LocationSite 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.
NetworkBerkeley Digital Seismic Network (BK)
Bay Area Regional Deformation Network Network (BARD)
Borehole ConditionsThe sensors are installed in a near-surface vault and covered with rocks and foam in order to provide thermal stability.
GPS Monument DescriptionThreaded 5/8" rod cemented 0.8m deep into bedrock
Table of Seismic Instrumentation
|Broadband||Streckeisen STS-2 VBB Tri-Axial Seismometer||Q330HR-GFE||BH?,HH?,LH?,VH?||00|
|Accelerometer||Kinemetrics FBA ES-T Accel. (2 g max 10 v/g)||Q330HR-GFE||HN?||00|
|GPS||SEPT POLARX5||Ashtech Choke-Ring||SCIGN Short||-|
Waveforms and associated metadata, and GPS data, are available at the Northern California Earthquake Data Center (NCEDC).
- BK Information Directory, including
Data completeness is defined both as "Completeness of observations" and "Cycle slips per observation". "Completeness of Obs." is the number of epochs in the final RINEX file normalized to the expected number. This percentage will go down if time is missing from the RINEX file. "Cycle slips per Obs." is the total number of detected cycle slip normalized to the total number of observations in the RINEX file. This number will increase as the receiver loses lock on satellites more frequently.
The effects of multipath on the data are estimated by parameters for L1 and L2 (MP1 and MP2 respectively); see Estey and Meertens (GPS Solutions, 1999) for derivation. The daily value is the RMS of MP1 and MP2 throughout the day and for all satellites. Higher values indicate a greater prevalence and/or strength of multipathing, i.e. objects on the ground are providing multiple reflection pathways from the satellite to antenna.
The Signal-to-Noise ratios are the mean values above the QC elevation mask for L1 and L2 respectively.