Electromagnetic Field Measurements

In collaboration with Professor Frank Morrison of the Department of Civil and Environment Engineering, the Berkeley Seismological Laboratory has established electromagnetic field observatories at 2 BDSN sites.

Sites were initially established at SAO and PKD1. When the BDSN site at PKD1 was relocated to PKD, additional electromagnetic sensors were installed there. The PKD1 equipment was recorded in parallel with PKD for several months and then removed in early 1999.

In addition, the BSL collaborates with Professor Steve Park of UC Riverside to collect and archive data from a low-frequency, long-baseline electric field project at site PKD2. This experiment (which is separate from the observatory at site PKD1), uses an 8 channel Quanterra datalogger to record the data.

Network Code

BK

Current Station Equipment

3-component magnetic field sensors (0.0001 - 20 Hz)
Multiple component electric field sensors (DC - 20 Hz)
24-bit Quanterra digital data logger
GPS clock
Continuous telemetry to UC Berkeley
Dialup telephone access
72 hour backup power supply

Recorded Channels

Sensor	SEED Channels	Rate (samples/sec)	Sampling Mode	FIR Filter
Magnetic	VT?	0.1	Continuous	Acausal
Magnetic	LT?	1.0	Continuous	Acausal
Magnetic	BT?	40.0	Continuous	Acausal
Electric	VQ?	0.1	Continuous	Acausal
Electric	LQ?	1.0	Continuous	Acausal
Electric	BQ?	40.0	Continuous	Acausal

Network State of Health

The BSL has been working with Dr. Gary Egbert at Oregon State University to install his software for automated data processing and quality control.

Characteristics of integrated spectra and parameters of the first Earth-ionosphere cavity resonance are calculated routinely.

Station and Channel Information

• Map of BDSN stations
• Table of BDSN stations
• BK Information Directory, including
  • List of station locations
  • List of available channels
    • Year/month/day format
    • Year,doy format
  • Instrument Response
    • SEED format
    • Simplified Responses
• Information on Quanterra Timing Errors

Data access

Waveform data from the BK network are available in SEED format. 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
  • SeismiQuery at the NCEDC
  • NetDC Request Form
• Requesting data
  • NetDC Request Form

Help on using these tools is available.

The results of daily magnetic activity and Schumann resonance are available via anonymous ftp at the NCEDC. The README file provides some additional information.

Reports and Publications

• Reports on the Electromagnetic observatories from the Annual Report of the BSL:
  • 2001-2002
  • 2000-2001
  • 1999-2000
  • 1998-1999
  • 1997-1998

Collaborations

The electromagnetic observatories were initiated as a cooperative project with UC Riverside and Stanford University with funding from the USGS NEHRP.