Extreme plate boundary localization promotes shallow earthquake slip at the Japan Trench

Science
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Abstract

The 2011 Mw9.1 Tohoku-oki earthquake is exceptional among great earthquakes for having peak slip of ~50-70 m on the shallowest portion of the plate boundary megathrust. International Ocean Discovery Program Expedition 405 drilled multiple holes through the megathrust in the large slip region and at a Pacific Plate input site. The megathrust preferentially develops at the top or base of the pelagic clay in the input section where pronounced contrasts in physical properties are present. This results in a narrow, weak fault located at a major mechanical contact between frontal prism mud and subducted clay. Localization imposed by the input section enhances the tendency for shallow seismic slip, showing the Japan Trench may be more susceptible to ruptures with large shallow slip than margins without weak clays.

Suggested Citation

Kirkpatrick, J.D., Savage, H.M., Regalla, C., Shreedharan, S., Ross, C., Okuda, H., Nicholson, U., Ujiie, K., Hackney, R., Conin, M., Pei, P., Satolli, S., Zhang, J., Fulton, P., Ikari, M., Kodaira, S., Maeda, L., Okutsu, N., Toczko, S., and Eguchi, N., 2025, Extreme plate boundary localization promotes shallow earthquake slip at the Japan Trench: Science, v. 391, no. 6784, p. 489-493, https://doi.org/10.1126/science.ady0234.

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Publication type Article
Publication Subtype Journal Article
Title Extreme plate boundary localization promotes shallow earthquake slip at the Japan Trench
Series title Science
DOI 10.1126/science.ady0234
Volume 391
Issue 6784
Year Published 2025
Language English
Publisher American Association for the Advancement of Science
Contributing office(s) Earthquake Science Center
Description 5 p.
First page 489
Last page 493
Country Japan
Other Geospatial Japan Trench
Additional publication details