Shortening of recurrence interval of Boso slow slip events in Japan

• Published in: Geophysical research letters Vol. 41; no. 8; pp. 2762 - 2768
• Main Author: Ozawa, Shinzaburo
• Format: Journal Article
• Language: English
• Published: Washington Blackwell Publishing Ltd 28.04.2014; John Wiley & Sons, Inc
• Subjects: Boso slow slip; Coastal environments; Computer simulation; Coulomb friction; Earthquakes; Failure; Geophysics; Intervals; Mathematical models; Numerical simulations; recurrence interval; Seismic phenomena; Simulation; Slip; Stresses; Temporal logic; Japan
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2014GL060072

A slow slip event occurred off the coast of the Boso peninsula, Japan, from approximately 28 December 2013 to 10 January 2014. The estimated aseismic slip expanded slightly southward and westward over time with a moment magnitude of 6.5, which was the smallest value since 1996. The recurrence interval has decreased from approximately 6.4 to 2.2 years from 1996 to 2014. One explanation of this shortening is the change in Coulomb failure stress due to the 2011 Mw9.0 Tohoku earthquake and its afterslip. Another interpretation is related to a scenario observed in several numerical simulation studies, in which the recurrence interval of slow slip becomes shorter as the time nears a large earthquake. This case will constrain the physical processes of a slip cycle. The Boso slow slip events together with the Tohoku earthquake and its afterslip changed the stress state for the anticipated interplate earthquake near the Sagami trough. Key Points Spatial and temporal slow slip process in Boso slow slip, JapanShortening of the recurrence intervalDCFS is increasing after the Tohoku earthquake