[S-CG58] Science of slow earthquakes: Toward unified understandings of whole earthquake process

[SCG58-29] Experiments simulating the subduction of seamounts beneath a viscoelastic crust

*並木 敦子¹ (1.広島大学　総合科学部)

キーワード：地震、海山

Topographies on a subducting plate changes the frictional force between the hanging wall and the foot wall. Indeed, the subducting seamounts seem to regulate the source locations of slow earthquakes. However, the quantitative evaluation of the effects of seamounts has not yet understood. Here, we performed a series of experiments of subducting seamounts beneath a viscoelastic rock analog. Associate with the increase of displacement of the slider as an analog of the subducting slab, the stress accumulates on the downdip edge, while in the updip, space appears between the hanging wall and seamount to be friction-free. We also found that, when there are topographies on the surface of the foot wall, topographies develops on the surface of the deformable hanging wall. The interlock of the topographies on the facing surfaces alters the temporal and spatial friction. Our results suggest that a unimodal topography on the subducting plate is the most efficient way to cause a repeating earthquake.