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Mini-Plate Boundary Observatory Project

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Station Information | Data access | Reports | Collaborations

The Integrated Instrumentation Program for Broadband Observations of Plate Boundary Deformation, commonly referred to as ``Mini-PBO'', is a joint project of the BSL, the U.S. Geological Survey (USGS) at Menlo Park, the Department of Terrestrial Magnetism at Carnegie Institution of Washington (CIW), and the IGPP at UC San Diego (UCSD). It augments existing infrastructure in central California to form an integrated pilot system of instrumentation for the study of plate boundary deformation, with special emphasis on its relation to earthquakes. This project is partially funded through the EAR NSF/IF program with matching funds from the participating institutions and the Southern California Integrated Geodetic Network (SCIGN).

The project has three components. One is focused on the San Francisco Bay area, and augments existing instrumentation along the Hayward and San Andreas faults with up to 8 sites with borehole tensor strainmeters and seismometers, downhole pore pressure and tilt sensors, and geodetic GPS receivers. The second component of this project is to link the BARD network in central and northern California to the SCIGN network in southern California through the installation of 9 continuous GPS sites in the Parkfield area of central California. The third component is InSAR and supports the skeleton operations of a 5-m X-band SAR downlink facility in San Diego to collect and archive radar. In addition, some funds are used to develop an online SAR database for WInSAR users.

As part of the first component, four borehole sites were drilled during the summer/fall of 2001, at Ohlone Park (OHLN) in Hercules, on San Bruno mountain (SBRN) near Brisbane, at the Marin Headlands (MHDL) in Golden Gate National Recreation Area, and on Ox Mountain (OXMT) near Half Moon Bay. Two of these sites have been instrumented with newly fabricated borehole tensor strainmeters and seismometers, and downhole pore pressure and tilt sensors will be added in the near future.

Please note - as of 5:00 PM 6/30/2003, the BSL has modififed the FIR filters on the Mini-PBO Q4120 dataloggers. The NCEDC News report contains more complete information.

Network Codes
BK (also includes the BDSN, NHFN, and MOBB) and UL

Typical Station Equipment
3-component tensor strainmeter (designed and built by CIW)
3-component geophone (Mark Products)
Atmospheric pressure
Pore Pressure
Geodetic GPS
Heat flow
24-bit Quanterra Q4120 digital data logger and a 18-bit ZENO-3200 data logger
GPS clock
Continuous telemetry to UC Berkeley and to the USGS
Backup power supply

Typical Recorded Channels
As part of this collaboration, the borehole sites will have two sets of digital data loggers. The table below lists which channels will be recorded and the SEED network and location codes which will be used.

Sensor Network
Rate (samples/sec) Sampling Mode Datalogger
Tensor strainmeter UL RS1, RS2, RS3 T0 1/600 Continuous ZENO-3200
Tensor strainmeter BK US1, US2, US3 0.01 Continuous Q4120
Tensor strainmeter BK VS1, VS2, VS3 0.1 Continuous Q4120
Tensor strainmeter BK LS1, LS2, LS3 1.0 Continuous Q4120
Tensor strainmeter BK BS1, BS2, BS3 20.0 Continuous Q4120
Tensor strainmeter BK HS1, HS2, HS3 100.0 Continuous Q4120
Geophone BK BP1, BP2, BP3 20.0 Continuous Q4120
Geophone BK EP1, EP2, EP3 100.0 Triggered Q4120
Atmospheric Pressure UL RD1 T0 1/600 Continuous ZENO-3200
Atmospheric Pressure BK LDO 1.0 Continuous Q4120
Pore Pressure BK LDD 1.0 Continuous Q4120
Heat Flow (?) UL ?? T0 (?) 1/600 Continuous ZENO-3200
Tiltmeter (?) UL RAX, RAY (?) T0 (?) 1/600 Continuous ZENO-3200

Network State of Health
State of health is monitored through automated REDI alarm system notifications, waveform evaluations of significant and repeating small earthquakes and using SeisNetWatch software.

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.

GPS data from Mini-PBO sites are available through the BARD network:


As described about, the Mini-PBO is a collaborative experiment among