Seismic Arrays

San Jose Dense Seismic Array

The Evergreen Basin Seismic Imaging Study - June 16-30, 2002 is an associated study being performed in a collaborative effort between the U.S. Geological Survey and the Santa Clara Valley Water District Map showing the layout of the seismic array.

The San Jose dense seismic array (click on image to view larger map) is composed of 41 K2 strong-motion seismographs deployed in northeastern San Jose, California to evaluate in detail the effects of a deep sedimentary basin and shallow sedimentary deposits on earthquake ground motions. This urban array is located near the eastern edge of the Santa Clara Valley and spans the Evergreen sedimentary basin identified by gravity data. The stations are approximately equally spaced 1 km (0.62 miles) apart, with 3 stations spaced 110m apart. The array covers an area of roughly 5 x 5 = 25 square km (3 x 3 = 9 square miles). The array is designed to investigate the spatial variation of earthquake ground motions and how this variation is related to the three-dimensional geologic structure of the area. Most of the stations are located in the homes of residents of the area. The majority of the funding for this array is through the Pacific Gas and Electric Company of California.

Please contact David Carver (carver at usgs.gov) for a list and/or data for the seismic events recorded by the San Jose Dense Seismic Array.

Seattle Dense Seismic Array

Please contact David Carver (carver at usgs.gov) for a list and/or data for the seismic events recorded by the Seattle Dense Seismic Array.