The pattern of energy release during the Imperial Valley, California, earthquake of 1940 is studied by analyzing the El Centro strong motion seismograph record and records from the Tinemaha seismograph station, 546 km from the epicenter. The earthquake was a multiple event sequence with at least 4 events recorded at El Centro in the first 25 seconds, followed by 9 events recorded in the next 5 ...

[1] A pulse-like disturbance traveling across the Los Angeles basin was observed on 12 October 2001 with seismographs of the TriNet network. This wave had a period of about 1000 s and a propagation speed of about 10 m/s, much slower than seismic waves. The seismograph data were compared with barograph data, and a good correlation was found so the wave was determined to be atmospheric in origin....

Receiver function analysis is one of the most powerful methods for modeling the subsurface structure beneath a seismograph station. Based on the assumption that similar receiver functions should be observed at stations located close to each other, we can construct a spatial distribution of a seismic velocity interface, such as the Moho discontinuity, to trace the distribution of P-to-S (Ps) con...