Open Access

Repeating short- and long-term slow slip events with deep tremor activity around the Bungo channel region, southwest Japan

Earth, Planets and Space201457:BF03351875

https://doi.org/10.1186/BF03351875

Received: 31 August 2004

Accepted: 27 March 2005

Published: 20 June 2014

Abstract

We report the repeating occurrence of short- and long-term slow slip events (SSE) which are accompanied by deep tremor activity around the Bungo channel region, southwest Japan. Both of these activities are detected by NIED Hi-net, which is composed of densely distributed observatories equipped with a set of tiltmeter and a high-sensitivity seismograph. Since the short-term SSE is small in magnitude, GPS can detect only the long-term SSE. Some of these episodes have nearly the same surface deformation pattern. This shows the existence of ‘slow slip patches’ on a plate interface, where the episodic slow slip is the characteristic slip behavior. We observe a change in periodicity and size of the short-term episode after the onset of the long-term SSE. Moreover, the long-term slow slip accelerates when the short-term activity takes place. This suggests that there is an interaction between these two types of SSEs.

Key words

Subduction zone Philippine Sea plate plate interface Hi-net borehole tiltmeter GPS slow slip patch