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  • November 4, 2019
[Frontier Letter] Structural heterogeneity in and around the fold-and-thrust belt of the Hidaka Collision zone, Hokkaido, Japan and its relationship to the aftershock activity of the 2018 Hokkaido Eastern Iburi Earthquake

The 2018 Hokkaido Eastern Iburi Earthquake (M=6.7) occurred at a very deep depth (~37 km) beneath the foreland fold-and-thrust belt of the Hidaka Collision Zone, Hokkaido, Japan. From the previously acquired controlled source seismic data, Iwasaki et al. (2019) revealed the detailed structure beneath this fold-and-thrust belt and its relationship with the aftershock activity of this earthquake. Relocated aftershocks are at depths of 7-45 km with steep geometry, extending to the uppermost mantle of the eastward descending NE Japan arc. High aftershock activity in the mantle indicates that the cold crust delaminated from the Kuril Arc side by the arc-arc collision prevents the thermal circulation and cools the mantle to generate favorable conditions for brittle fracture. View articles:

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