A two-day field activity on Lower Crystal Springs Reservoir (the portion of the reservoir north of Highway 92) to test the use of the Seistec, a high-resolution surface-towed seismic profiler, and ground-penetrating radar in fresh water environments. Permit to conduct this survey received from the San Francisco Water Department.
Description
Chief Scientist: Jon Childs. Geophysical data (Seistecprofiler, groundpenetratingradar) of field activity F-1-99-NC in Lower Crystal Springs Reservoir from 05/12/1999 to 05/13/1999
Location
Lower Crystal Springs Reservoir
Summary
Seistec data (5/12/99) recorded with MudSeis in SEG-Y format. Data were written to hard disk and transferred (ftp) to nemo for ProMax processing. No hard copy or removeable media data were recorded.
Comments
Data acquisition: Seistec data (5/12/99) recorded with MudSeis in SEG-Y format. Data were written to hard disk and transferred (ftp) to nemo for ProMax processing. No hard copy or removeable media data were recorded. 5/12/99 - Departed MarFac at 0815 (PST) for Crystal Springs; met Mike Byrne, Watershead Manager, at the boat ramp off Skyline Blvd, approx. 1/2 mile north of Highway 92. Boat inspected and approved for use in the reservoir. Mobilized the Seistec instrument, navigational and recording equipment. Launched Fast Eddie and Seistec; underway by about 11 am. Starting at noon (1900 GMT) recorded seven crossings of the reservoir, observing moderate penetration of sediment (15-20 meters) in places, and considerable bathymetric relief. Reservoir has a very steep western margin, and several incisions and platforms that may represent scarps or other features associated with the San Andreas Fault. Seistec acquisition parameters: 105 J power, 0.25 sec fire rate; 16 kHz sampling, 80 meter record length, Seistec internal receiver only, 300 Hz - 10= kHz bandpass 5/13/99 - Departed MarFac at 0800 (PST), and arrived Crystal Springs approx. 0830. Configured a small Zodiac raft to support the ground-penetrating radar (GPR) antennas. The GPR was tested in shallow water near the shore at the boat ramp, but wind conditions were too severe to launch the whaler and zodiac. Further refinement of the GPR deployment is required. Returned to MarFac by noon.
Staff information imported from InfoBank
Jon Childs (USGS Western Region) - Chief Scientist
Pat Hart (USGS Western Region) - Unspecified
Larry Kooker (USGS Western Region) - Electrical Technician
Gerry O'Brien (USGS Western Region) - Driver
Walter Barnhardt (USGS Western Region) - Unspecified
Diane Minasian (USGS Western Region) - Unspecified
