Triggering of Aftershocks of the Japan 2011 Earthquake by Earth Tides

TL;DR

This study investigates the influence of Earth tides on the aftershock sequence of the 2011 Japan earthquake, revealing significant periodicities at tidal frequencies through spectral and time-domain analysis.

Contribution

It introduces a combined spectral and time-domain approach to detect tidal influences on earthquake aftershocks, highlighting the role of Earth tides in seismic activity.

Findings

Detection of diurnal and semi-diurnal periodicities in aftershock sequence

Evidence of Earth tide influence on large aftershocks

Enhanced understanding of tidal triggering mechanisms

Abstract

The aftershock sequence of the devastating Japan earthquake of March 2011 is analyzed for the presence of periodicities at the Earth tide periods. We use spectral analysis as well as a time-domain method KORRECT developed earlier to detect presence of diurnal and semi-diurnal periodicities in the sequence of aftershocks (M \geq 4). This suggests that large aftershocks in the fault zone of the Japan 2011 earthquake were strongly influenced by Earth tides.