Long-period surface waves of four western United States earthquakes recorded by the Pasadena strainmeter

Long-period surface waves recorded on the north-south Pasadena strainmeter are used to determine the seismic moments and fault parameters of the 19 May 1940 Imperial Valley, California, the 16 December 1954 Dixie Valley and Fairview Peak, Nevada, and the 18 August 1959 Hebgen Lake, Montana, earthquakes. Synthetic strain seismograms are matched with the observed strainmeter seismograms. Source parameters from the strainmeter modeling are more consistent with source parameters estimated from geodetic and geologic information than parameters estimated from short-period (