PG&E presented its plans to the public on Thursday (July 21) for off-shore, three-dimensional seismic studies to further define the geophysical characteristics of the region off of the San Luis Obispo County coast.
The presentations came at meetings held by the State Lands Commission, which is preparing an environmental impact report on the planned survey that will encompass several hundred square miles.
While PG&E’s geological experts have determined that potential impacts of seismic activity – including the Shoreline fault – fall within seismic margins for Diablo Canyon, and continue to study the nearby faults per the company’s commitment to the NRC, PG&E is currently collecting additional data using 3D (low energy) imagery to better define activity.
Stuart Nishenko, PG&E’s senior seismologist, told those at the meeting that the 3D (high energy) work is intended to help enhance scientific understanding of the length, depth and location relationships of the Hosgri, Shoreline and San Simeon faults.
The work will be done primarily by a seismic research vessel towing an array of instruments that will emit sounds through the water to listen for echoes. The echoes will allow scientists to generate 3D pictures of the faults in the earth’s crust.
PG&E has asked, and the Nuclear Regulatory Commission has agreed, to hold off on license renewal decision until the proposed 3D seismic studies are complete.
PG&E also has requested that the CPUC suspend proceedings associated with PG&E’s license renewal application until the studies are completed, reviewed thoroughly and independently, and shared with the NRC.
Many local elected officials – including boards of supervisors for San Luis Obispo and Santa Barbara counties – support the additional 3D studies near Diablo Canyon
About two dozen community members attended the meetings. Some expressed concerns that the 3D seismic studies might impact commercial fishing. PG&E will continue to work with local residents to listen to their concerns.
PG&E hopes to conduct the surveys between August and December 2012 and issue its final seismic report in August 2013.