The Loma Prieta, California, earthquake of October, 17, 1989: Marina District

Abstract

A northwest-trending valley in the bedrock surface is buried by firm Pleistocene bay clay, dense to very dense Pleistocene sand, soft Holocene bay deposits, loose to dense Holocene beach and dune sands, and artificial fill that have an aggregate maximum thickness of about 90 m. Depth to the ground-water table is generally less than 2.7 m (9 ft) except in one area of thick dune sand; the groundwater table is quite shallow in some places where no surface effects of liquefaction related to the earthquake were reported.