A great tsunami earthquake component of the 1957 Aleutian Islands earthquake

Earth and Planetary Science Letters
By: , and 

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Abstract

The great 1957 Aleutian Islands earthquake ruptured ∼1200 km of the plate boundary along the Aleutian subduction zone and produced a destructive tsunami across Hawaiʻi. Early seismic and tsunami analyses indicated that large megathrust fault slip was concentrated in the western Aleutian Islands, but tsunami waves generated by slip in the west cannot explain the large observed runup in Hawaiʻi far to the southeast. Recently mapped 1957 geologic deposits on eastern Aleutian Islands suggest occurrence of very large nearby slip. Jointly modeling tsunami runup along the eastern Aleutian and Hawaiian Islands together with tide gauge recordings across the Pacific resolves 12-26 m shallow slip along 600 km of the eastern Aleutian Islands in addition to modest, deeper western slip inferred from seismic records. The eastern near-trench slip results in an MW 8.3-8.6 tsunami earthquake component of the MW 8.6-8.8 rupture, comparable in size to the adjacent 1946 Aleutian tsunami earthquake to the east. The reexamination of the 1957 rupture confirms the tsunami hazards posed by the eastern Aleutian subduction zone to Hawaiʻi and lays the groundwork for investigation of large prehistoric earthquakes through modeling tsunami runup inferred from stratigraphic observations to constrain their rupture processes.


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Publication type Article
Publication Subtype Journal Article
Title A great tsunami earthquake component of the 1957 Aleutian Islands earthquake
Series title Earth and Planetary Science Letters
DOI 10.1016/j.epsl.2024.118691
Volume 637
Year Published 2024
Language English
Publisher Elsevier
Contributing office(s) Alaska Science Center Geology Minerals, Pacific Coastal and Marine Science Center
Description 118691
Country United States
State Alaska
Other Geospatial Aleutian Islands
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