Dramatic examples of catastrophic damage from an earthquake occurred in 1989, when the M 7.1 Lorna Prieta rocked
the San Francisco Bay area, and in 1994, when the M 6.6 Northridge earthquake jolted southern California. The
surprising amount and distribution of damage to private property and infrastructure emphasizes the importance of
seismic-hazard research in urbanized areas, where the potential for damage and loss of life is greatest.
During April 1995, a group of scientists from the U.S. Geological Survey and the University of
Tennessee, using an echo-sounding method described below, is collecting data in San Antonio
Park, California, to examine the Monte Vista fault which runs through this park. The Monte Vista
fault in this vicinity shows evidence of movement within the last 10,000 years or so. The data will
give them a "picture" of the subsurface rock deformation near this fault. The data will also be used
to help locate a trench that will be dug across the fault by scientists from William Lettis &
Associates.
