Critical point theory of earthquakes: Observation of correlated and cooperative behavior on earthquake fault systems

Abstract

The critical point theory for earthquakes was originally proposed to explain the scaling relations observed in earthquakes, including the Gutenberg-Richter frequency-magnitude relation and the Omori's law for aftershocks. In this model, main shocks, their foreshocks and aftershocks are all associated with the formation of a correlated, cooperative spatial region with high stress. Until now, only indirect evidence of the existence of these correlated regions has been reported. Here in this paper we present observations and analyses that allow us to directly map the high stress, spatially correlated regions preceding four major earthquakes, i.e. the 1992 Landers (California), 1995 Kobe (Japan), 1999 Chi-Chi (Taiwan) and 1999 Hector Mine (California) earthquakes. We therefore conclude that the locations and extent of large main shocks and their immediate aftershocks can be determined from seismicity data taken prior to the main shocks, and provide additional evidence in support of the critical point theory for earthquakes. Copyright 2006 by the American Geophysical Union.