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Data report for the 1993 seismic refraction experiment in the San Francisco Bay Area, California

1994; United States Department of the Interior; Linguagem: Inglês

10.3133/ofr94241

2332-4899

W.M. Kohler, R. D. Catchings,

Geophysical Methods and Applications

Data from the SGRs were recorded on cartridge tapes.At the end of each deployment, a Dell PC computer was used to read the cartridge tapes, and convert the data to SEGY format.The SEGY data were then written to nine-track tape reels.The original field data were recorded at a sampling interval of 2 milliseconds, but the data were decimated to an 8 milliseconds sampling interval before the SEGY tapes were written.Data from each Reftek were recorded on a hard disk contained within the seismograph.After each deployment, the data from each instrument were uploaded to a SUN workstation.Computer programs on the SUN workstation were used to reformat the data to SEGY format.The data were then written to nine-track SEGY tape reels.Data from the ocean bottom seismometers, stored on exabyte tapes, were received from Woods Hole Oceanographic Institute.Data from each of the three types of instruments were read on the VAX/VMS 4000/100 computer "SAMOA" at the U.S.G.S. in Menlo Park.Using software written in-house, the data were "windowed", so that each trace has a 32 second record length.Latitude and longitude coordinates were compiled and written to the trace headers, as well as shotpoint-to-station distances and azimuths.Finally, using the VAX computer, we wrote a SEGY tape containing data from all three types of instruments.During the experiment, several mistakes were made which had adverse effects on the data quality and quantity.Due to an instrument programming error, no SGR data were recorded for deployment 1, stations 4068 -4098.Also, we did not obtain any data recordings from the Reftek instruments for deployment 2, shot 10, shotpoint 5.However, this shot was extremely weak, and we do not think that any useful data was lost.Inspection of the record sections (appendix D) reveals that several of the shots were extremely weak, including all the shots on the southeast end of the East Bay line (table 2, shotpoints 4, 5, 12, 13, 14, and 15).In addition, shotpoints 17 and 18 on the Cross Line were weak.We speculate that one or more of the following effects may have been responsible for the weak recordings:We wish to give thanks to the many individuals and organizations who made this experiment possible.Some of the key players are listed below.