Coastal and Marine Geology
Map of proposed pipelines, geographic, and geologic features mentioned in this report. LAX is the Los Angeles International Airport; AES is the name of a company (from figure 1).
This report examines the geologic hazards that could affect the OceanWay Secure Energy Project, a proposal by Woodside Natural Gas to build liquefied natural gas (LNG) facilities offshore of the Palos Verdes Peninsula in southern California. These facilities would include a Deepwater Port (DWP), including submersible buoys, manifolds, and risers, which would be situated in 3,000 feet of water about 23 miles offshore. The DWP would be connected to onland facilities by 35 miles of pipeline, which would come onshore near the Los Angeles International Airport.
This report also examines the geologic hazards that could affect a proposed alternate location for the DWP that would be located approximately 20 miles offshore of Orange County, with the pipeline making landfall near the AES energy plant at Huntington Beach (note: AES is the company’s name, not an acronym).
The U.S. Geological Survey (USGS) does not make any recommendation for or against the OceanWay Secure Energy Project. Instead, it is the USGS’s goal to provide accurate and up-to-date geologic information for use by public policy officials involved in the approval process and for use by engineers in the design process if such a project does go forward.
As part of the Deepwater Port license application, Fugro West, Inc., has prepared a document discussing geologic hazards in the area, titled “Exhibit B Topic Report 6 – Geological Resources” (Fugro West, Inc., 2007); hereafter, this will be called the “Geological Resources document.” Our report summarizes the regional geologic hazards, reviews the Geological Resources document, and makes recommendations for future work to more fully assess the geologic hazards.
The LNG facility is proposed to lie in a region of known geologic hazards that include:
The regional geologic hazards and the Geological Resources document were reviewed by 27 scientists from the USGS and the California Geological Survey (CGS). Overall, the reviewers found that the Geological Resources document represents most of the geologic hazards in the project area. However, there are also some hazards not completely represented. We note that there are new consensus seismic hazard reports that have been released since the Geological Resources document was written. In some cases, as detailed throughout the rest of the report, additional scientific studies are recommended to improve geological hazard assessments.
New scientific assessments based on our recommendations will not necessarily reveal increased hazard. For example, the Geological Resources document calculates greater seismic hazard in the project area than do the updated National Seismic Hazard Maps (Petersen and others, 2008). Conversely, we make recommendations for more detailed assessment of hazards posed by tsunamis and sediment transport events because we believe that the impact of such events may be underrepresented in the Geological Resources document. This enhanced scientific information would provide a better basis for evaluating this application and for the engineering design of the project should it go forward.
Download this report as a 66-page PDF file (of2008-1344.pdf; 1.2 MB)
For questions about the content of this report, contact Stephanie Ross.
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