Synchronous Tremor Modulation During the Passage of 2012 Super-typhoon Jelawat in Nankai Trough: By Chance or Real Consequence?

Abstract

Episodic tremor and slow-slip events are sensitive to the exogenous stress perturbations process. Although tidal and remote triggering phenomena of tremors are well-established facts; however, the triggering mechanism induced by low-barometric pressure of typhoons or larger storms remains poorly addressed. In this paper, a time-synchronous tremor modulation is presented from the northern Kii Peninsula in western Japan, associated with a large Super Typhoon Jelawat, which occurred on September 30, 2012. It has been argued that such tremor excitation may not be correlated with other types of signal, such as the short-term or long-term slow-slip events, tidal effect, or remote triggering. The atmospheric low-pressure condition during the passage of super typhoon Jelawat causes vertical crustal uplift by a negative load and hence possibly enhances the thrust motion due to unclamping effects on the fault. Therefore, it is suggested that the synchronous tremor modulation process in the northern Kii Peninsula is a real consequence induced by super typhoon Jelawat.