Deployed several dense arrays of Kinemetrics K2 acceleroraphs in the San Jose, California area to determine the effects of sedimentary basins on earthquake ground motions. The San Jose array was installed beginning in Feb of 1999 and was operated intact until about May 2004. The array was 36 or more instruments in equilateral triangles 1 km on a side. After the San Jose array was dismantled we created other, similiar, arrays in nearby Saratoga, Los Gatos, Milpitas and Fremont, California.