SUBMARINE GEOLOGIC INVESTIGATION FOR LIQUEFIED NATURAL GAS FACILITY, SOUTHERN CALIFORNIA BORDERLAND.

Liquefied natural gas (LNG) facilities are unique to energy conversion plants in the coastal zone in that they require a pile-supported trestle, 1 to 2 km long, perpendicular to the shoreline. Because of the structure projecting seaward, detailed analysis of the seafloor along the tresle alignment must be made in addition to more routine areal studies offshore from the site. In addition to the trestle, there are seawater intake and discharge pipes, 3 m in diameter, that extend to depths ranging from 5 to 20 m. There are also docking facilities and, at some exposed sites, a parallel breakwater 200 to 300 m long that creates quiet water for anchoring. Detailed knowledge of coastal processes is needed because of the shoreline structures appurtenant to the main gasification facility. This paper presents techniques applicable to offshore geological analysis for siting LNG facilities. Particular emphasis is given to the Point Conception, California site where considerable effort has been expended in offshore investigations by many workers, including the senior author. Refs.