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

• Published in: Earth, planets and space planets and space, 2005-01, Vol.57 (10), p.961-972
• Main Authors: HIROSE, Hitoshi, OBARA, Kazushige
• Format: Article
• Language: English
• Subjects: Cosmochemistry. Extraterrestrial geology; Earth sciences; Earth, ocean, space; Exact sciences and technology
• ISSN: 1343-8832; 1880-5981; 1880-5981
• DOI: 10.1186/BF03351875

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.