Abstract
The sliding movement between oceanic and crustal plates in subduction zones is accommodated through both earthquakes and quasi-static or transient aseismic slip. On northeastern Japan megathrust, aseismic transients, known as slow-slip events, are suggested to precede and trigger major earthquakes in their immediate surroundings. However, the geodetic evidence for these episodic slow-slip events, as well as their link to the seismicity on neighboring locked segments of the megathrust, is missing. Here, we combine the on-shore geodetic data set with seismic observations during the interseismic period of 1996–2003 and demonstrate that episodic slow-slip events are prevalent across the down-dip portion (∼30–70 km depth) of the megathrust and the associated stress changes modulate the seismicity rate on the neighboring seismogenic zone. Consequently, small- to moderate-size earthquakes are periodically triggered, whose interaction through a domino effect might occasionally lead to major earthquakes. This observation has a profound impact on the estimation of seismic hazard in the region, introducing a new triggering mechanism that acts across the megathrust to the extent that has not been acknowledged before.
Original language | English (US) |
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Article number | 116261 |
Journal | Earth and Planetary Science Letters |
Volume | 540 |
DOIs | |
State | Published - Jun 15 2020 |
Keywords
- GPS
- Japan subduction zone
- earthquake triggering
- kinematic modeling
- repeating earthquakes
- slow-slip events
ASJC Scopus subject areas
- Geophysics
- Geochemistry and Petrology
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science