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USGS CMG L-1-91-NC Metadata Skip navigational links Search InfoBank     Activities: by ID   by Platform   by Year   by Region   by Participant   by Organization   by Project/Theme   with Incomplete IDs   Disclaimer   Activity First Letter: A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z   0   1   2   3   4   5   6   7   8   9   Virtual Globes: Atlas  (GE)    Samples  (GE)    Illuminate Oceans  (GE)    Earthquakes  (GE)    Get GE    InfoBank examples    State Waters L-1-91-NC links... Metadata & Data: Bathymetry   Metadata   Navigation   Seismic   nav (GE GM)   seis (GE GM)   times (GE GM)   Formal Metadata: Frequently-Anticipated Questions   Outline   Parseable Text   XML       Metadata ID L-1-91-NC Abstract Chief Scientists: Pat Hart, Jill McCarthy. Geophysical data (3dot5khz, 12khz, uniboom, airgun, airgunmonitor) of field activity L-1-91-NC in San Francisco Bay from 09/03/1991 to 09/20/1991 Project/Theme Bay Area Seismic Imaging Experiment (BASIX) Chief Scientist Pat Hart Jill McCarthy Activity Type Geophysical Platform Samuel Phillips Lee Area of Operation San Francisco Bay Location map Bounding Coordinates 38.11173 -123.52004    -121.70993 37.20842 Dates 09/03/1991 (JD 246) to 09/20/1991 (JD 263) Analog Materials list Index map Crew Al McClenghan Ship Captain Chris Poppe Chief Mate, USGS Western Region Bill Lafleur Chief Engineer, USGS Western Region Jill McCarthy Chief Scientist, USGS Western Region Kevin O'Toole Mechanical Technician, USGS Western Region Walt Olson Mechanical Technician, USGS Western Region Larry Kooker Electronics Technician, USGS Western Region Bill Robinson Electronics Technician, USGS Western Region Jim Vaughan Electrical Engineer, USGS Western Region Dave Hogg Electronics Technician, USGS Western Region Kaye Kinoshita Navigator, USGS Western Region George Knudson Mechanical Technician, Fairfield Steve Higgins Electronics Technician, Fairfield Mike Pawlik Electronics Technician, Fairfield Tom McEvilly Geophysicist, University of California, Lawrence Berkeley Laboratories Pat Hart Geophysicist, USGS Western Region Jon Childs Geophysicist, USGS Western Region Kevin Furlong Geophysicist, Pennsylvania State University Terry Proffer Geophysicist, Haliburton Geophysicist. Pat McClellan Geophysicist, City Of San Leandro Mike Marlow Watchstander, USGS Western Region Kathy Furlong Unspecified Investigator, Pennsylvania State University Kate King Unspecified Investigator, CNN Rick Blackbird Unspecified Investigator, CNN Chris Vincent Unspecified Investigator, CNN Gordon Smith Ship Captain, David Johnston Mark McLaughlin Unspecified Investigator, David Johnston Tom Parsons Unspecified Investigator, Stanford University - David Johnston Michael Hamer Navigator, David Johnston, USGS Western Region Roberto Anima Ship Captain, Fast Eddy, USGS Western Region Shawn Dadisman Unspecified Investigator, Fast Eddy, USGS Western Region Armando Buciaga Unspecified Investigator, Fast Eddy, USGS Western Region Tom Chase Ship Captain, Chase Boat, USGS Western Region Pete Dartnell Unspecified Investigator, Chase Boat, USGS Western Region Roy Kiesling Vol. Unspecified Investigator, Chase Boat, USGS Western Region Greg Gabel Ship Captain, Caltrans Holly Ryan Unspecified Investigator, Caltrans David Verdonck Geophysicist, Pennsylvania State University, LLL Dennis Mann Ship Captain, Revenge, USGS Western Region Ray Sliter Unspecified Investigator, Revenge, USGS Western Region Joe Svitek Unspecified Investigator, Revenge, USGS Western Region Rich Clymer Unspecified Investigator, Mako, USGS Western Region Pat Williams Unspecified Investigator, Mako, USGS Western Region Peter Barnes Ship Captain, R/V Estero, USGS Western Region Erik Gize Unspecified Investigator, R/V Estero, USGS Western Region Jean Riordan Unspecified Investigator, USGS Western Region Norman Maher Unspecified Investigator, USGS Western Region Vicky Goetcheus Unspecified Investigator, USGS Western Region Dave Scholl Geophysicist, USGS Western Region Eleni Karageorgi Unspecified Investigator, Lawrence Berkeley Laboratories Joel Rosenbaum Photographer, Vacaville Reporter Robert Reed Unspecified Investigator, Vacaville Reporter George Thompson Geophysicist, Stanford University Ben Page Geophysicist, USGS Western Region David McMahon Unspecified Investigator, BC&DC Doug Prose Photographer, USGS Western Region Nina Luttinger Photographer, USGS Western Region Tracy Vallier Geologist, USGS Western Region Andy Michael Geophysicist, USGS Western Region Stephanie Ross Navigator, USGS Western Region Diana Collins Unspecified Investigator, USGS Western Region June Matsueyda Unspecified Investigator, USGS Western Region Equipment Used 3dot5khz 12khz uniboom airgun airgunmonitor Purpose Furlong and others (1989) proposed the possibility that the network of faults that bound the San Francisco Bay Area are linked structurally and are all part of an evolving fault system. To test the Furlong and others (1989) model and to obtain fundamental information on the crustal structure and fault geometries that underlie the San Francisco Bay Area, the USGS, in conjunction with the University of California, Stanford University, Pennsylvania State University, and Lawrence Berkeley Laboratory, conducted a major seismic reflection investigation in the fall of 1991 utilizing the marine waterway system that dissects the Bay Area. This study, known as the Bay Area Seismic Imaging Experiment (BASIX) consisted of three complementary seismic reflection and refraction profiling methods: high resolution seismic reflection profiling, wide-angle reflection/refraction profiling, and multichannel seismic profiling. The high-resolution, shallow penetration data were acquired to constrain near-surface faulting, while the wide-angle reflection/ refraction data were acquired to constrain the deep-crustal velocity structure of the crust. (Open-File Report 93-301). Information to be Derived Three complementary seismic reflection and refraction profiling methods: high resolution seismic reflection profiling, wide-angle reflection/refraction profiling, and multichannel seismic profiling. The high-resolution, shallow penetration data were acquired to constrain near-surface faulting, while the wide-angle reflection/refraction data were acquired to constrain the deep-crustal velocity structure of the crust. (Open-File Report 93-301). Summary A total of 140 km of multichannel reflection data were acquired across the San Francisco Bay Area during 14 nights of profiling. Although each night of profiling was assigned a different line number, several of the lines overlap and they were thus processed together as merged profiles. All totaled, there were four distinct segments to the experiment. The first segment began in the Sacramento River near Rio vista and proceeded west through Honker, Suisun, and San Pablo Bays (lines 101 through 110). The next two segments ran north- south from Richmond to Angel Island (line 113), and from the Bay Bridge to just north of the San mateo Bridge (line 111). The fourth and final segment began in the vicinity of Alcatraz Island and extended west underneath the Golden Gate Bridge, 6 km into the open waters of the Pacific (lines 201-202). 60 to 118 Telseis receivers were moored to the edge of the dredged shipping channel at 100 to 200 m intervals for a fixed spread of 6 to 12 km in length. Each day the receiver array was repositioned, and each night the S.P. Lee steamed along the hydrophone array, with its airgun array firing. The day-to-day small-boat operations began first with the retrieval of the Telseis instruments deployed the previous day. This process utilized a fleet of 4-5 small boats that ranged in size from 6 to 15 m. Once retreived, the instruments were brought back to the S.P. Lee for recharging. The R.V. David Johnston trailed behind these small vessels and recovered the associated buoys and anchors. The Johnston also recorded navigational fixes, which were required in order to check for possible drift of the instrument sites during the night; although anchors were used to maintain instrument position, currents were strong enough in a few areas to move the anchors between deployment and retrieval. Once the instrument retrieval was complete, the Johnston would begin laying out the next line segment. A GPS and Del Norte triangulation system were used to measure the 100- or 200-m distance separating instrument sites. The receiver line was positioned so as to minimize bends in the profile and to keep the buoys out of the active shipping channel. At each site, anchors were deployed and navigation fixes were taken; the anchored sites were marked by orange buoys. The smaller boats followed behind and clipped the recharged Telseis units with cabled hydrophones to these buoys. The hydrophones were weighted so as to minimize movement on the seafloor. The final phase of operation was airgun profiling. Each night the S.P. Lee acquired approximately 24 km of reflection data by looping through the receiver array twice. Along 10 of the 13 multichannel lines the S.P. Lee fired the airgun array while steaming first from east to west and then, reversing course, duplicated the line by steaming from west to east, further doubling the number of airgun shots available for stacking of the seismic signal. In addition to the 13 reflection lines acquired in San Francisco Bay and the Golden Gate region, the airgun array on the S.P. Lee was used primarily as a seismic source for wide-angle profiles recorded along three other lines: the N-S trending line OBS1 in San Francisco Bay; a short transit leg, line TR1 SW of the Golden Gate; and the E-W trending line OBS2 on the continental margin. Lines OBS1 and OBS2 were obtained along two separate deployment of 6 USGS ocean bottom seismometers (OBS) deployed by investigators from the USGS Branch of Atlantic Marine Geology and Woods Hole Oceanographic Institution. The shot interval along line 112/OBS1 was 50 m. The shot interval for lines TR1 and OBS2 was approximately 75 m. Line OBS2 was located coincident to seismic reflection line 13 of Lewis (1990) in order to provide deep structural control on the continental margin west of the San Andreas fault. Publications Anima, R.J., Williams, Patrick L., and McCarthy, J., 1992, High-resolution marine seismic reflection profiles across East Bay faults, in Galehouse, Jon S., ed., Programs and abstracts of the Second conference on Earthquake hazards in the eastern San Francisco Bay area: California Division of Mines and Geology Special Publication, v. 113, p. 4. Hart, P.E., Clymer, R.W., and Karageorgi, E.D., 1992, Geometry of the San Francisco Bay area faults; preliminary results from BASIX, in Galehouse, Jon S., ed., Programs and abstracts of the Second conference on Earthquake hazards in the eastern San Francisco Bay area: California Division of Mines and Geology Special Publication, v. 113, p. 30. McEvilly, T.V., and McCarthy, Jill, 1992, BASIX; the Bay Area Seismic Imaging Experiment report, in Galehouse, Jon S., ed., Programs and abstracts of the Second conference on Earthquake hazards in the eastern San Francisco Bay area: California Division of Mines and Geology Special Publication, v. 113, p. 47. McCarthy, Jill, and Hart, Patrick E., 1993, Data report for the 1991 Bay area seismic imaging experiment (BASIX): U.S. Geological Survey Open-File Report 93-0301, 26 p. Hart, P., McCarthy, J., Karageorgi, E., and McEvilly, T., 1993, Seismic reflection profiling in the San Francisco Bay area; the 1991 Bay Area Seismic Imaging Experiment (BASIX): Geological Society of America Abstracts with Programs, v. 25, no. 6, p. 417-418. McCarthy, J., Hart, P., Karageorgi, E., and McEvilly, T., 1993, Seismic profiling across an evolving transform margin; results from the 1991 Bay Area Seismic Imaging eXperiment (BASIX): Geological Society of America Abstracts with Programs, v. 25, no. 6, p. 310. Brocher, Thomas M., McCarthy, Jill, Hart, Patrick E., Holbrook, W. Steven, Furlong, Kevin P., McEvilly, Thomas V., Hole, John A., and Klemperer, Simon L., 1994, Seismic evidence for a lower-crustal detachment beneath San Francisco Bay, California: Science, v. 265, no. 5177, p. 1436-1439. Childs, J.R., Hart, P.E., McCarthy, J., and Marlow, M.S., 1994, High-resolution seismic-reflection studies of submerged fault zones throughout the San Francisco Bay area: American Geophysical Union Eos, Transactions, v. 75, no. 44, Supplement, p. 684. McCarthy, J., Hart, P.E., Anima, R., Oppenheimer, D., and Parsons, T., 1994, Seismic evidence for faulting in the western Sacramento Delta region, Pittsburg, California: American Geophysical Union Eos, Transactions, v. 75, no. 44, Supplement, p. 684-685. McCarthy, J., Hart, P.E., and Oppenheimer, D., 1995, High angle faulting in western Sacramento Delta region, Pittsburg, California: American Association of Petroleum Geologists Bulletin, v. 79, no. 4, p. 592. Parsons, Tom, McCarthy, Jill, and Hart, P.E., 1994, The nature of lower crustal reflectors beneath San Francisco Bay, California: American Geophysical Union Eos, Transactions, v. 75, no. 44, Supplement, p. 643. Williams, P.L., McEvilly, T.V., Anima, R., McCarthy, J., Nakata, T., Okamura, M., and Shimazaki, K., 1993, Fault activity, geometry, and recurrence behavior at the junction of the Rodgers Creek and Pinole faults, California: American Geophysical Union Eos, Transactions, v. 74, no. 43, Supplement, p. 411. Holbrook, W. Steven, Brocher, T.M., McCarthy, Jill, Hole, J.A., and ten Brink, U.S., 1994, Crustal structure beneath the San Francisco Bay Block and Central California continental margin: American Geophysical Union Eos, Transactions, v. 75, no. 44, Supplement, p. 664. Pope, D.C., Brocher, T.M., McCarthy, J., Karageorgi, E.D., and Holbrook, W.S., 1993, Comparison of recording technology for onshore-offshore seismic profiling of continental margins; examples from BASIX: American Geophysical Union Eos, Transactions, v. 74, no. 43, Supplement, p. 445. Brocher, Thomas M., McCarthy, Jill, and Holbrook, W. Steven, 1996, Imaging the transform plate boundary in the San Francisco Bay area, California: Geological Society of America Abstracts with Programs, v. 28, no. 7, p. 216. Brocher, Thomas M., and Moses, Michael J., 1993, Onshore-offshore wide-angle seismic recordings of the San Francisco Bay Area Seismic Imaging Experiment (BASIX): the five-day recorder data: U.S. Geological Survey Open-File Report 93-276, 89 p. Got Help? For L-1-91-NC, we would appreciate any information on -- contract, days at sea, dive count, funding, information specialist, kms of navigation, national plan, NGDC Info, notes, organization, owner, ports, project number, scanned materials, seismic description, station count, station description, submersible, tabulated info. Skip footer navigational links InfoBank   Menlo Park & Santa Cruz Centers   St. Petersburg Center   Woods Hole Center   Coastal and Marine Geology Program   Geologic Information   Ask-A-Geologist   USGS Disclaimer

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