6:15 PM - 7:30 PM
[SCG62-P15] Modeling various slow slip events along the Hikurangi subduction zone
Keywords:modeling, slow slip events, Hikurangi subduction zone, a rate- and state-dependetn friction law, shallow short-term SSEs, Manuatsu long-term SSEs
We modeled short-term and long-term SSEs along the Hikurangi subduction zone using a rate- and state-dependent friction law and considered realistic configurations of the plate interface. We set the coupling region where a-b is negative based on the study of interseismic coupling by Wallace et al. (2009). By setting the effective stress and the critical displacement of shallow short-term SSEs to approximately 1.5 MPa and 2.4 mm, respectively, we could reproduce SSEs with a duration of 1--3 weeks and recurrence interval of 3 years. Additionally, by setting the effective stress and the critical displacement of the Manuatsu long-term SSEs to approximately 3.0 MPa and 7.2 mm, respectively, we were able to reproduce SSEs with a duration of 0.5 years and recurrence interval of 5 years. The effective stress of the Manawatu SSE zone is two times larger than that of the short-term SSE zones. However, the ratio of the effective stress to the critical displacement of the Manawatu SSE zone is smaller than that of the short-term SSE zones. We could also reproduce a sequence of simultaneous short-term SSEs and a long-term Manawatu SSE as observed by Wallace et al. (2009). The occurrence of the various slow slip events suggests heterogeneous distributions of constitutive law parameters along the Hikurangi subduction zone.