U.S. Geological Survey
Open-File Report 98-139
Version 1.0

Multibeam Data and Socio-Economic Issues in West-Central San Francisco Bay

Rock Pinnacles on the San Francisco Bay Floor, I

The Exxon Valdez, which was bound for San Francisco Bay at the time, ran aground on a bedrock pinnacle in Prince William Sound (AK) in 1989 spilling 11 million gallons of crude oil. The cleanup and mitigation costs for that event will probably exceed $5 billion. For comparison, a 1996 oil spill in San Francisco Bay involved 8000 gallons (less than 0.1% of the Valdez spill) and cost $10 million to clean up. The U.S. Congress currently is considering legislation that would require the lowering of the bedrock pinnacles in west-central Bay to promote safe navigation (Miller, 1997).

Some perspective views and a cross-section of the rock pinnacles appear in the table that follows. The perspective views show the outlines of areas shallower than 55 feet, and depressions deeper than 95 feet.

See a table with larger images (128 kb). A larger version of each thumbnail image can be displayed.

larger version (118 kb)	Hypothetical Remedy for a Threat to Navigation larger version (32 kb)
larger version (111 kb)	larger version (110 kb)

• View of all three pinnacles (118 kb)
• Morphology of Harding Rock (111 kb)
• Harding Rock modification (110 kb)
• Harding Rock cross-section (32 kb)