资源环境科技发展态势分析平台

The interaction between earthquakes and volcanic eruptions is investigated by analyzing a modern seismic data catalog of centroid moment tensor solutions and eruption records summarized by the Smithsonian Institution. To determine the average features of the interactions, the numbers of earthquakes that occurred before and after the initiation of each eruption with a volcanic explosivity index of larger than or equal to 2 are analyzed. The results show that moderate earthquakes, which have moment magnitudes of 5 to 6 (M-w 5-6), are activated within a horizontal distance of 50 km from volcanoes for about 0.3 years after the initiation of an eruption. About 13% of volcanic eruptions are accompanied by moderate earthquakes. The occurrence possibility of earthquakes every 0.1 years for 0.3 years after an eruption is about 5 times larger than normal. No significant dependence on the tectonic settings and major rock types is recognized.

Plain Language Summary Interaction between volcanic eruptions and earthquakes is one of the most interesting topics in the solid-earth science. Triggering of volcanic eruptions by large earthquakes have been studied for recent decades, but few studies examine the effects of volcanic eruptions on moderate and large earthquakes. The present study analyzed global seismic and volcanological data catalog that can be useful to systematically examine their interaction because the detection levels of observations are unified. The analyses show that moderate earthquakes with magnitudes of 5-6 occur around the volcanoes for about 0.3 years after the occurrence of eruptions. This new result provides us basic knowledge and important evidence to clarify the interaction mechanisms between the earthquakes and volcanoes. Also, because the moderate earthquakes occurring at shallow depths may cause significant hazards, their occurrence probability, which is first estimated by the present study, can be useful to prepare the earthquake hazards around volcanoes. Rapid publication is necessary to prepare for future volcanic and seismic disaster.