A large earthquake corresponds to the fast propagation of fracture. The nucleation of theearthquake source is the dynamic body (or dynamic process) which starts the fast propagation offracture. The dynamic body or dynamic process may be the fissure with a slow to fast propagatingspeed at the tip part of the source, including that it can have chemical corrosive process of staticor dynamic stress ; it can be the sudden-fast destabilizing region somewhere when the sourcefault of a large earthquake pre-slips ; it can also be a dynamic body on some part of source faultsurface whose physical feature becomes weak and produces stress concentration at its tip beforethe impending earthquake. In addition, it can be a dynamic fluid body of high pressure and hightemperature at depth forced to introde into the lot to accumulate tremendous elastic strain energy. The observations and studies of these dynamic bodies or dynamic processes mentioned abovecan contribute to the forecasting of large earthquakes.
Recent Developments in World Seismology
nucleation of earthquake source
occurrence of largeearthquake