National Centers for Environmental Information (NCEI)
COMMON DEPTH POINT (CDP) SEISMIC REFLECTION DATA
Data Announcement 87-MGG-03
Approximately 2,233-km of 24-channel common depth point (CDP) seismic-reflection profiles for purchase from the National Geophysical Data Center (NGDC) (now the National Centers for Environmental Information (NCEI)) for the Pacific Outer Continental Shelf off northern California and Oregon. The profiles were collected on the U.S., Geological Survey (USGS) R/V S.P. LEE Cruise No. L477NC during May 1977.
A sound source of five airguns with a volume of 1,326 cu.in.
of air compressed to approximately 32,000 psi were used.
The recording system consisted of a 24-channel, 2,400-m-long
streamer with a group interval of 100 m, and a GUS (Global
Universal Science) model 4200 digital recording instrument.
Shots were fired every 50 m. Navigational control for the
survey was provided by a Marconi integrated navigation
system using transit satellites and Doppler sonar augmented
by Loran C (Rho Rho). A 2-msec sampling rate was used in
the field. The data were later desampled to 4 msec during
the demultiplexing process. Record lengths vary from 5 to 9
sec of data below the seafloor. Processing was completed in
the sequence: editing-demultiplexing, velocity analysis,
CDP stacking, deconvolution filtering, and plotting on an