PG&E plans ocean seismic fault survey

The State Lands Commission is seeking public input on plans by PG&E to survey 516 square miles of ocean off San Luis Obispo County for earthquake hazards.

The agency is preparing an environmental review of work PG&E plans to do in late 2012 to further define earthquake faults in the vicinity of Diablo Canyon nuclear power plant. These include the Hosgri, San Simeon and Shoreline faults.

The work will consist of using air guns to emit bursts of high-energy sound into the ocean and then recording that sound with underwater microphones. Scientists will be able to generate a three-dimensional picture of the faults in the area based on how the sound travels through the Earth’s crust.

The agency will hold public hearings on the environmental effects of the survey work at 3 and 6 p.m. Thursday at the San Luis Obispo Library Community Room, 995 Palm St.

The fault-mapping work is a precondition for extending the operating licenses of Diablo Canyon’s two nuclear reactors to 2044 and 2045. Many local elected officials insisted that the work be done in light of the recent discovery of the Shoreline fault near Diablo Canyon and in the aftermath of the March 11 nuclear disaster in Japan.

The work will be done primarily by a research vessel that will tow an array of instruments through the water, PG&E spokesman Kory Raftery said.

The research ship will operate in two areas — one between Point Buchon and Point San Luis and the other between Cambria and Point Estero. These locations contain the Cambria and Point Buchon marine protected areas.

The Lands Commission will analyze a variety of possible environmental effects of the work, most notably on whales, seals and other marine animals. PG&E hopes to conduct the surveys between August and December 2012 and issue its final seismic report in August 2013.

For more information, visit the Lands Commission Web page at www.slc.ca.gov. Click on the CEQA updates link under the information tab.