PREMONITORY ELEVATION CHANGE BEFORE AN EARTHQUAKE BASED ON DILATANCY-DIFFUSION MODEL

Abstract

The dilatancy-diffusion model, recently proposed to explain premonitory changes in geo-physical and geochemical fields before several shallow earthquakes, implies uplift of the epicentral region. Based on a dilating sphere in an elastic half-space, simple formulas and a graph are presented which could be used to predict the magnitude and depth of the focus of a future earthquake if the magnitude of the dilatancy were known. Alternatively an estímate of the magnitude of the dilatancy can be made with the help of the graph by compiling information on maximum vertical displacement, depth of the center and the radius of the dilating sphere for earthquakes that are preceded by dilatancy.