The relationship between heat flow and seismicity in global tectonically active zones

Abstract

Abstract This study aims to analyze the complex relationship between heat flow and seismicity in tectonically active zones worldwide. The problem was quantitatively analyzed by using a geographic detector method, which is well suited for analyzing nonlinear relationships in geography. Moreover, β-value that describes the frequency-magnitude distribution is used to represent the seismicity. The results showed that heat flow (HF) = 84 mW/m2 is a critical point for the relevant mechanisms of heat flow with seismicity in these zones. When HF < 84 mW/m2, the heat flow correlates negatively with the β-value, with a correlation degree of 0.394. Within this interval, buoyant is a primary control on the stress state and earthquake size distribution. Large earthquakes occur more frequently in subduction zones with younger slabs that are more buoyant. Due to zones with a high ratio of large earthquake corresponds to low β-values, high heat flow values correspond to low β-values. When HF > 84 mW/m2, the heat flow correlates positively with the β-value, with a correlation degree of 0.463. Within this interval, the increased heat flow decreases the viscosity of the rock plate and then reduces the stress. Lower stress would correspond to a smaller earthquake and then a higher β-value. Therefore, high heat flow values correspond to high β-values. This research would be conducive to understand the geologic activity and be helpful to determine the accuracy and timeliness of seismic hazard assessment.