RUPTURE PROCESS OF THE JUNE 28, 1992 BIG BEAR EARTHQUAKE

The June 28, 1992 Big Bear earthquake in southern California was assumed to have ruptured along a northeast-trending plane, as suggested by long-term aftershock distribution. No surface rupture was found, however, and mainshock locations determined from both strong motion and TERRAscope data are mutually consistent and do not lie on the assumed fault plane. An integrated study involving waveform modeling, directivity and seismicity analyses suggests a complex rupture pattern, with significant short- and long-period energy propagating northwest along the presumed conjugate fault-plane.