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Overview of the Berkeley Digital Seismic Network


Geophysical Networks

Map of BSL networks


The Berkeley Digital Seismic Network (BDSN) is one of several networks of seismic instrumentation in northern and central California operated by the Berkeley Seismological Laboratory. Operations are partially supported by the USGS. The BDSN is an array of high dynamic range, broadband seismometers with collocated strong-motion accelerometers. Data from these stations are transmitted to UC Berkeley using continuous telemetry and are analyzed for earthquakes. 30 sites are currently operational and additional stations are planned. Two other BDSN sites consist of strong-motion accelerometers.

Notes: as of 6/15/2004, the BSL began migrating the BH channels of the BDSN from a sampling rate of 20 samples per second to 40 samples per second. The migration was complete as of 06/16/2004. The NCEDC News report contains more complete information.

As of 5:00 PM 6/30/2003, the BSL has modififed the FIR filters on the BDSN Q4120 dataloggers. The NCEDC News report contains more complete information.

Network Code
BK (also includes the NHFN, MPBO, and MOBB)

Typical Station Equipment
3-component broadband seismometer (Streckeisen STS-1, Streckeisen STS-2, Guralp CMG-40T, or Guralp CMG-3T)
3-component accelerometer (Kinemetrics FBA-23 or EpiSensor)
Pressure sensor
Temperature sensor
24-bit Quanterra digital data logger
GPS clock
Continuous telemetry to UC Berkeley
Dialup telephone access
72 hour backup power supply

Some sites also have additional sensors to measure borehole strain, electric and magnetic field variations, and crustal deformation.

Typical Recorded Channels
Sensor SEED Channels Rate (samples/sec) Sampling Mode FIR Filter
Broadband seismometer UHZ, UHN, UHE 0.01 Continuous Acausal
Broadband seismometer VHZ, VHN, VHE 0.1 Continuous Acausal
Broadband seismometer LHZ, LHN, LHE 1.0 Continuous Acausal
Broadband seismometer BHZ, BHN, BHE 40.0 (20.0 prior to 06/15/2004) Continuous Acausal
Broadband seismometer HHZ, HHN, HHE 80.0 or 100.0 Triggered Acausal for 80 sps; Casual for 100 sps since 7/1/2003
Accelerometer HLZ, HLN, HLE 80.0 or 100.0 Continuous Acausal for 80 sps; Casual for 100 sps since 7/1/2003
Temperature LKS 1.0 Continuous Acausal
Pressure LDS 1.0 Continuous Acausal

Network State of Health
Information about the state-of-health of the BDSN is generated daily. The most recent SOH entry indicates the mean data value, the standard error of the mean, and the number of samples in the record. Channels for which the mean is more than 1% of full-scale are indicated with a "*". Analysis of the background noise at BDSN sites are conducted weekly. The most recent plot compares the station by channel in the 32-128 second period range. Annual plots are available:
2002-2003 | 2001-2002 | 2000-2001 | 1999-2000
1998-1999 | 1997-1998 | 1995-1996
In addition, plots of the background noise level at each station are now available.

Station and Channel Information

Data access
Waveform data from the BK network are available in SEED format at the Northern California Earthquake Data Center. Several tools provide access to SEED format data at the NCEDC, both in terms of querying the archives and allowing data requests.

Help on using these tools is available.

The IRIS DMC also archives data for the BDSN station CMB.

Reports and Publications

Several stations of the BDSN are operated cooperatively by the Berkeley Seismological Laboratory in collaboration with: