Seismicity of Southern California: Earthquakes of ML 3.0 and Greater, 1975 through 1983

Abstract

The time period since the last published California Institute of
\nTechnology (CIT) earthquake catalog (Hileman 1974; Friedman 1976) has
\nseen many changes in data analysis and reporting procedures at the
\nSeismological Laboratory. CIT merged its operation with the U.S. Geological Survey (USGS) during this period. Digital recording (Johnson
\n1979) was introduced in 1977 and computer systems improved several times
\nsince. The seismic network itself expanded from 125 stations in 1975 to
\nmore than 200 in early 1983 (Figure 1). The result is an agglomeration
\nof data that way take a superhuman effort to sort through.
\nMuch use can be made, however, of a timely earthquake catalog which
\nis restricted to the larger earthquakes. We therefore present as
\ncomplete and reliable a list of events of ML 3.0 and greater as
\npossible, comprising 3,650 individual earthquakes.