Effects of nearby large earthquakes on the occurrence time of the Tokai earthquake—An estimation based on a 3-D simulation of plate subduction—

Abstract

An eastern half of the focal region of the 1854 Ansei-Tokai earthquake was not ruptured at the 1944 Tonankai earthquake and the area around Suruga Bay remained as a seismic gap (Ishibashi, 1981). As to the cause that the fault motion in 1944 did not extend to the eastern part, Mogi (1981) and Pollitz and Sacks (1995) considered effects of the 1891 Nobi earthquake of M8.0. In this paper, we evaluate quantitatively effects of nearby large earthquakes, the 1891 Nobi, the 1923 Kanto and the 1944 Tonankai earthquakes, on the occurrence time of the Tokai earthquake that has been anticipated to occur soon to fill the seismic gap, using a three-dimensional simulation model with a rate-and state-dependent friction law (Ruina, 1983). It is suggested that the occurrence of the Tokai earthquake was delayed by the 1891 Nobi earthquake, while it was advanced by the 1923 Kanto and the 1944 Tonankai earthquakes. We show that the sense and degree of the effect of nearby large earthquakes on the occurrence time of the anticipated Tokai earthquake depend on whether and how much the stress perturbation produced by the nearby earthquakes strengthens or weakens the stress accumulated in the coupling region, especially in the highly shearstressed ring zone (Kuroki et al., 2002). However it is difficult to say definitely how much the Tokai earthquake was delayed or advanced, because the magnitude of the effect is very sensitive to the location of the fault planes.

Stress triggering of large earthquakes complicated by transient aseismic slip episodes

“…In the meantime, Kuroki et al [2002, 2004] simulated the cycle of subduction zone earthquakes using a three‐dimensional fault model. When parameters were set in such a way that aseismic slip prevailed outside an isolated zone of seismic sliding, a ring‐shaped zone of high shear stress emerged around the rim of the seismically sliding region, and kept contracting with the passage of time.…”

“…In the wake of these pioneering studies, Kuroki et al [2004] conducted three‐dimensional modeling to evaluate the influence of great nearby earthquakes on the occurrence time of the Tokai earthquake off Japan. Liu and Rice [2007] investigated aseismic deformation events that are excited along a subducting plate boundary by a stress step.…”

Static Coulomb stress load on a three‐dimensional rate‐and‐state fault: Possible explanation of the anomalous delay of the 2004 Parkfield earthquake

“…They reported that tensional earthquakes advance the occurrence of the next earthquake and compressional earthquakes delay it, except for later parts of the cycle, where clock advance occurs. The research was followed by Kato [] and Kuroki et al [], who examined the effects of nearby earthquakes on earthquake cycles of large interplate earthquakes at subduction zones. Kuroki et al [] used a realistic 3‐D fault geometry and evaluated the effects of three large earthquakes on the Tokai earthquake, which is expected to occur in central Japan.…”

“…The research was followed by Kato [] and Kuroki et al [], who examined the effects of nearby earthquakes on earthquake cycles of large interplate earthquakes at subduction zones. Kuroki et al [] used a realistic 3‐D fault geometry and evaluated the effects of three large earthquakes on the Tokai earthquake, which is expected to occur in central Japan. Perfettini et al [] systematically analyzed CA on a 2‐D rate‐and‐state fault by means of loading the whole fault at various onset times within the earthquake cycle.…”

Forecast experiment on the Kamaishi repeating earthquakes based on numerical simulations using friction law

“…On the basis of their results, they calculated the afterslip during days 16-30 and compared it with the observed afterslip. Kato (2004a) and Kuroki et al (2004) examined the effects of nearby earthquakes on the occurrence time of large interplate earthquakes based on numerical simulations.…”