Tsunamigenic structures in a creeping section of the Alaska subduction zone

Anne Bécel, Donna J. Shillington, Matthias Delescluse, Mladen R. Nedimović, Geoffrey A. Abers, Demian Saffer, Spahr C. Webb, Katie M. Keranen, Pierre Henri Roche, Jiyao Li, Harold Kuehn

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Segments of subduction zones that are capable of generating tsunamigenic earthquakes appear to have characteristic structural configurations. These structures include heterogeneous plate interfaces, a small wedge of deformed sediment at the toe of the overriding plate (the frontal prism), and splay faults in the crust of the overriding plate that root within the plate boundary megathrust. Here we use seismic reflection imaging to show that these features also exist within a creeping segment of the Alaska subduction zone, the Shumagin Gap. We identify an active crustal-scale normal fault system that dips landward and resembles that involved in the 2011 Tohoku-oki earthquake in Japan. We also find that the Shumagin Gap has a small frontal prism, a deep-water splay fault, and that the plate interface here is rough and thinly sedimented. We propose that lateral propagation of rupture from a neighbouring segment into the Shumagin Gap may explain a tsunamigenic earthquake that occurred there in 1788 and that tsunamigenic potential should be considered in hazard assessments for the region. Our results demonstrate that structural configurations similar to those in Tohoku may exist in other subduction zones, including within creeping segments or segments with no record of historical megathrust earthquakes, but are underrecognized. Identifying similar configurations globally may improve our ability to anticipate regions capable of generating large tsunamis.

Original languageEnglish (US)
Pages (from-to)609-613
Number of pages5
JournalNature Geoscience
Volume10
Issue number8
DOIs
StatePublished - Aug 1 2017

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subduction zone
earthquake
Tohoku earthquake 2011
hazard assessment
plate boundary
tsunami
normal fault
seismic reflection
rupture
deep water
crust
sediment

All Science Journal Classification (ASJC) codes

  • Earth and Planetary Sciences(all)

Cite this

Bécel, A., Shillington, D. J., Delescluse, M., Nedimović, M. R., Abers, G. A., Saffer, D., ... Kuehn, H. (2017). Tsunamigenic structures in a creeping section of the Alaska subduction zone. Nature Geoscience, 10(8), 609-613. https://doi.org/10.1038/NGEO2990
Bécel, Anne ; Shillington, Donna J. ; Delescluse, Matthias ; Nedimović, Mladen R. ; Abers, Geoffrey A. ; Saffer, Demian ; Webb, Spahr C. ; Keranen, Katie M. ; Roche, Pierre Henri ; Li, Jiyao ; Kuehn, Harold. / Tsunamigenic structures in a creeping section of the Alaska subduction zone. In: Nature Geoscience. 2017 ; Vol. 10, No. 8. pp. 609-613.
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Bécel, A, Shillington, DJ, Delescluse, M, Nedimović, MR, Abers, GA, Saffer, D, Webb, SC, Keranen, KM, Roche, PH, Li, J & Kuehn, H 2017, 'Tsunamigenic structures in a creeping section of the Alaska subduction zone', Nature Geoscience, vol. 10, no. 8, pp. 609-613. https://doi.org/10.1038/NGEO2990

Tsunamigenic structures in a creeping section of the Alaska subduction zone. / Bécel, Anne; Shillington, Donna J.; Delescluse, Matthias; Nedimović, Mladen R.; Abers, Geoffrey A.; Saffer, Demian; Webb, Spahr C.; Keranen, Katie M.; Roche, Pierre Henri; Li, Jiyao; Kuehn, Harold.

In: Nature Geoscience, Vol. 10, No. 8, 01.08.2017, p. 609-613.

Research output: Contribution to journalArticle

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AU - Shillington, Donna J.

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AU - Nedimović, Mladen R.

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AU - Li, Jiyao

AU - Kuehn, Harold

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Bécel A, Shillington DJ, Delescluse M, Nedimović MR, Abers GA, Saffer D et al. Tsunamigenic structures in a creeping section of the Alaska subduction zone. Nature Geoscience. 2017 Aug 1;10(8):609-613. https://doi.org/10.1038/NGEO2990