This grant will fund research through the Small Grants for Exploratory Research program to investigate the physical conditions in an earthquake hypocentral zone through the decay rate of aftershocks. Although the decay rate of aftershocks has been studied in the past, it has not been satisfactorily explained with a physical basis. Temperature is one of the candidates for a major controlling factor but establishing a relationship with aftershock decay rate is complicated by lack of data and the potential for other controlling factors. This work will attempt to isolate the temperature controlling factor by means of Japanese heat flow data in regions of active seismicity. If successful, the results will provide useful constraints on earthquake nucleation models. This research is a component of the National Earthquake Hazard Reduction Program.
