Late Holocene paleoseismology of Shuyak Island, Alaska

Shennan, Ian; Brader, Martin D.; Barlow, Natasha L.M.; Davies, Frank P.; Longley, Chris; Tunstall, Neil

Abstract

We report stratigraphic evidence of land-level changes along the eastern portion of the Alaska-Aleutian megathrust. Four marshes on Shuyak Island record variable amounts of coseismic deformation during four pre-20th century earthquakes. We combine these data with paleoseismic evidence from across the Kodiak, Kenai and Prince William Sound segments of the megathrust. These indicate that in the last 2000 years, AD 1964 was the only one to rupture all three segments simultaneously and generate a Mw 9.2 earthquake. The Kodiak segment ruptured independently on four further occasions with magnitudes > Mw 8.0; in AD 1788 and c.400 (440–320) BP, and independently but around the times of great earthquakes in the Prince William Sound segment c.850 and c.1500 BP.

Citation

Shennan, I., Brader, M. D., Barlow, N. L., Davies, F. P., Longley, C., & Tunstall, N. (2018). Late Holocene paleoseismology of Shuyak Island, Alaska. Quaternary Science Reviews, 201, 380-395. https://doi.org/10.1016/j.quascirev.2018.10.028

• Journal Article Type: Article
• Acceptance Date: Oct 19, 2018
• Online Publication Date: Oct 29, 2018
• Publication Date: Dec 1, 2018
• Deposit Date: Oct 12, 2018
• Publicly Available Date: Oct 30, 2018
• Journal: Quaternary Science Reviews
• Print ISSN: 0277-3791
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 201
• Pages: 380-395
• DOI: https://doi.org/10.1016/j.quascirev.2018.10.028