Arc Explorer
Themes visible in the above map: SHIPS
TRACKLINES, LATITUDE/LONGITUDE, COASTLINE and LAND. The SHIPS
trackline numbers are contained in the LINE field of the SHIPS
TRACKLINES theme.
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SHIPS (Seismic Hazard
Investigations in Puget Sound) Multichannel Seismic Reflection
Tracklines
David C. Mosher,
Yanpeng Mi, Roy D. Hyndman, Mike Fisher and SHIPS Scientific Party
SHIPS was a multidisciplinary seismic
experiment conduct in the marine waters of Puget Sound, Juan de
Fuca Strait and Strait of Georgia. It was conducted by a consortium
of universities and institutions, including the United
States Geological Survey,
the Geological Survey of Canada, the
Department of Natural Resources of Washington State, the
University of Victoria, the University
of British Columbia, Dalhousie
University, the
University of Washington, Oregon
State University and the University
of Texas, El Paso (Fisher et al., 1999).
Data collected include multi-channel seismic reflection, wide-angle
reflection, and refraction, through shore-based and marine receiving
stations.
The component of SHIPS data used in
this report is the multichannel seismic reflection profiles along
the tracklines shown in the accompanying map. These data were
collected with a 6700 cu.in., 12-gun source array, and a 96-channel,
2375 m-long hydrophone array. Channel spacing is 25 m. Data were
digitally acquired at a 4 ms sample rate for a window length of
16 s. Shot spacing was 50 m. The gun array and the hydrophone
streamer were towed at 10 m below sea surface. For the data presented
in this report, the near 48 channels were processed to four seconds
depth to enhance the shallower part of the section. Processing
included: geometrical spreading correction, common depth point
(CDP) and super CDP sorting, predictive deconvolution, spectrum
balancing, bandpass filtering (0-80 Hz), velocity analysis on
the super CDP gather, low-cut tau-p velocity filtering, CDP normal
moveout correction, DMO correction, AGC, CDP stack, F-X deconvolution
and phaseshift migration. Velocity analyses were conducted on
every 84th CDP, or about every kilometre. Processing resulted
in 24-fold data with 12.5 m spacing between CDP's.
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References
Fisher, M.A., and Expedition Participants,
1999. Seismic Survey Probes Urban Earthquake Hazards in Pacific
Northwest. EOS,
Transactions, American Geophysical Union v. 80, p. 13-17.
Reference citation:
Mosher, D.C., Mi, Y., Hyndman, R.D., Fisher, M., and SHIPS Scientific
Party, 2000. SHIPS
(Seismic Hazard Investigations in Puget Sound) Multichannel Seismic
Reflection Tracklines, in:
Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B.,
and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de
Fuca Strait; a digital geological and geophysical atlas. Geological
Survey of Canada Open File Report 3931
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