Citation

Ye L, Kanamori H, Rivera L, Lay T, Zhou Y, Sianipar D, Satake K. Sci. Adv. 2020; 6(3): eaaz1377.

Affiliation

Earthquake Research Institute, University of Tokyo, Tokyo, Japan.

Copyright

(Copyright © 2020, American Association for the Advancement of Science)

DOI

10.1126/sciadv.aaz1377

PMID

31998846

PMCID

PMC6962046

Abstract

On 22 December 2018, a devastating tsunami struck Sunda Strait, Indonesia without warning, leaving 437 dead and thousands injured along the western Java and southern Sumatra coastlines. Synthetic aperture radar and broadband seismic observations demonstrate that a small, <~0.2 km³ landslide on the southwestern flank of the actively erupting volcano Anak Krakatau generated the tsunami. The landslide did not produce strong short-period seismic waves; thus, precursory ground shaking did not provide a tsunami warning. The source of long-period ground motions during the landslide can be represented as a 12° upward-dipping single-force directed northeastward, with peak magnitude of ~6.1 × 10¹¹ N and quasi-sinusoidal time duration of ~70 s. Rapid quantification of a landslide source process by long-period seismic wave inversions for moment-tensor and single-force parameterizations using regional seismic data available within ~8 min can provide a basis for future fast tsunami warnings, as is also the case for tsunami earthquakes.

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).

Language: en