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Great tsunamigenic earthquakes during the past 1000 yr on the Alaska megathrust

Ian Shennan, Natasha Barlow, Gary Carver, Frank Davies, Ed Garrett and Emma Hocking
Great tsunamigenic earthquakes during the past 1000 yr on the Alaska megathrust
Geology (Boulder) (June 2014) 42 (8): 687-690


Large to great earthquakes and related tsunamis generated on the Alaska megathrust produce major hazards for both the area of rupture and heavily populated coastlines around much of the Pacific Ocean. Recent modeling studies suggest that single-segment ruptures, as well as multi-segment, 1964-type ruptures, can produce great earthquakes, >M8, and significant hazards both in the near field and to distant locations through the generation of tsunamis. We present new paleoseismological data from Kodiak Island and a new analysis of radiocarbon data based on Bayesian age modeling to combine our observations with previous geological, historical, and archaeological investigations. We suggest that, in addition to multi-segment ruptures in A.D. 1964 and 1020-1150 (95% age estimate), a single-segment rupture occurred in 1788, with coseismic land-surface deformation across Kodiak Island and a tsunami that is recorded in historical documents and in sediment sequences, and another, similar rupture of the same Kodiak segment at A.D. 1440-1620. These indicate shorter intervals between ruptures of the Kodiak segment than previously assumed, and more frequent ruptures than for the Prince William Sound segment.

ISSN: 0091-7613
EISSN: 1943-2682
Serial Title: Geology (Boulder)
Serial Volume: 42
Serial Issue: 8
Title: Great tsunamigenic earthquakes during the past 1000 yr on the Alaska megathrust
Affiliation: Durham University, Department of Geography, Durham, United Kingdom
Pages: 687-690
Published: 20140609
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 23
Accession Number: 2014-048994
Categories: Seismology
Document Type: Serial
Bibliographic Level: Analytic
Annotation: GSA Data Repository item 2014255
Illustration Description: illus. incl. sketch map
N56°43'60" - N58°00'00", W154°52'00" - W152°10'00"
Secondary Affiliation: Carver Geologic, USA, United StatesNorthumbria University, GBR, United Kingdom
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2022, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 201427
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