During the L1-78-SC cruise of the USGS research vessel S. P. Lee (April 25 - May 11, 1978) seven sonobuoy profiles and 200 km of 24-channel seismic reflection data were recorded in the outer southern California Continental Borderland. These data were obtained, at the request of the Deep Sea Drilling Project (DSDP), to evaluate possible drill sites along the southern California continental margin.
The drill sites shown in Figure 1 were proposed by the Ocean Paleo-environmental Panel for DSDP Leg 63--secheduled for Sept. - Nov. 1978. These sites were selected in order to provide an expanded Neogene record of paleoceanographic-paleoclimatic events and associated evolutionary development of planktic communities along the eastern side of the north Pacific Ocean. Site selection was made prior to this survey on the basis of available single-channel seismic reflection profiles. Thus, the proposed sites shown on Fig. 1 may be relocated or eliminated when the data presented in this report are incorporated with earlier data. The combined data will be evaluated for safety and pollution hazards by Leg 63 site proponents and the DSDP safety panels.
The ship's tracks (Fig. 1) were located by an integrated Satellite-Loran C-Doppler Sonar navigation system. Average survey speed was about 5 kts. A 1326 cu in (21,723 CC) tuned air gun array provided the sound source for both reflection and refraction profiles. The air gun array was fired at 50 m (about 18 sec.) intervals by the integrated navigation system.
