The relationship among earthquake location, magnetization, and subsurface temperature beneath the Taiwan areas

Earthquake locations are mainly determined by the strength of the rocks and the subsurface temperature. However, other geophysical factors may play a role in the localization of earthquakes. Noting that the anomaly in magnetic intensity is positive in the aseismic regions of Taiwan, we investigate the spatial correlation between the magnetization and earthquake locations. We estimate the magnetization from the surface down to the depth of 45 km from the magnetic intensity map at the surface of Taiwan. Focusing on the regions where the rocks are brittle and the temperature less than 450 °C, we find that earthquakes tend to occur in the strata with relatively-low magnetization. Conversely and in agreement with the observation that rocks undergo ductile deformation when the temperature is greater than 450 °C, we find that the subsurface temperature is the key determinant for the localization of earthquakes within regions where the temperature is higher than 450°C. Magnetization should be considered as an additional parameter that governs the earthquake locations.