Recurrence and Extent of Great Earthquakes in Southern Alaska During the Late Holocene from an Analysis of the Radiocarbon Record of Land-Level Change and Village Abandonment
The incidence of plate-boundary earthquakes across 3 prospective tectonic segments at the Alaska subduction zone (ASZ) in the late Holocene is reconstructed from geological evidence of abrupt land-level change and archaeological evidence of discontinuities in occupation of native villages. Bracketin...
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ftunivarizonaojs:oai:journals.uair.arizona.edu:article/3020 2023-05-15T17:04:41+02:00 Recurrence and Extent of Great Earthquakes in Southern Alaska During the Late Holocene from an Analysis of the Radiocarbon Record of Land-Level Change and Village Abandonment Hutchinson, Ian Crowell, Aron L 2007-01-01 application/pdf https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/3020 eng eng Radiocarbon https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/3020/2778 https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/3020 Radiocarbon; Vol 49, No 3 (2007); 1323-1385 0033-8222 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peer-reviewed Article 2007 ftunivarizonaojs 2020-11-14T17:53:01Z The incidence of plate-boundary earthquakes across 3 prospective tectonic segments at the Alaska subduction zone (ASZ) in the late Holocene is reconstructed from geological evidence of abrupt land-level change and archaeological evidence of discontinuities in occupation of native villages. Bracketing radiocarbon ages on uplifted and down-dropped coastal deposits indicate that great earthquakes likely ruptured the plate interface in the eastern segment (Prince William Sound [PWS]) about 800, 1400, 22002300, 26002700, 31003200, and 36003700 cal BP. Evidence for an event about 1900 yr ago, and the possibility that the 26002700 cal BP event was a closely spaced series of 3 earthquakes, is restricted to parts of Cook Inlet. Geological evidence from the central (Kenai [KEN]) segment is fragmentary, but indicates that this segment likely ruptured about 1400 yr ago and in the triple event about 26002700 yr ago. The geological record from the Kodiak-Katmai (KOKA) segment at the western end of the ASZ has limited time-depth, with localized evidence for ruptures about 500, 1000, and 1300 yr ago. 14C ages and stratigraphic descriptions from 82 prehistoric villages and camps on the coast of the Gulf of Alaska reveal fluctuations in site activity that correlate with paleoseismic episodes. Hiatuses in site occupation occurred about 800, 1400, and 2200 yr ago in the PWS and KEN segments. The fragmentary older record from the KEN segment also reveals a hiatus about 2700 yr ago. The 22002300 and 26002700 cal BP events are also recorded in the KOKA segment, and the great earthquake at about 3200 cal BP may also be recorded there. This suggests that, although the PWS and KEN segments behave as a coherent unit of the Alaska megathrust, the KOKA segment is characterized by semi-independent behavior. At least 2, and perhaps as many as 4, of the last 7 prehistoric great earthquakes at this plate boundary did not propagate this far west. Article in Journal/Newspaper Kodiak Alaska Journals at the University of Arizona Gulf of Alaska |
institution |
Open Polar |
collection |
Journals at the University of Arizona |
op_collection_id |
ftunivarizonaojs |
language |
English |
description |
The incidence of plate-boundary earthquakes across 3 prospective tectonic segments at the Alaska subduction zone (ASZ) in the late Holocene is reconstructed from geological evidence of abrupt land-level change and archaeological evidence of discontinuities in occupation of native villages. Bracketing radiocarbon ages on uplifted and down-dropped coastal deposits indicate that great earthquakes likely ruptured the plate interface in the eastern segment (Prince William Sound [PWS]) about 800, 1400, 22002300, 26002700, 31003200, and 36003700 cal BP. Evidence for an event about 1900 yr ago, and the possibility that the 26002700 cal BP event was a closely spaced series of 3 earthquakes, is restricted to parts of Cook Inlet. Geological evidence from the central (Kenai [KEN]) segment is fragmentary, but indicates that this segment likely ruptured about 1400 yr ago and in the triple event about 26002700 yr ago. The geological record from the Kodiak-Katmai (KOKA) segment at the western end of the ASZ has limited time-depth, with localized evidence for ruptures about 500, 1000, and 1300 yr ago. 14C ages and stratigraphic descriptions from 82 prehistoric villages and camps on the coast of the Gulf of Alaska reveal fluctuations in site activity that correlate with paleoseismic episodes. Hiatuses in site occupation occurred about 800, 1400, and 2200 yr ago in the PWS and KEN segments. The fragmentary older record from the KEN segment also reveals a hiatus about 2700 yr ago. The 22002300 and 26002700 cal BP events are also recorded in the KOKA segment, and the great earthquake at about 3200 cal BP may also be recorded there. This suggests that, although the PWS and KEN segments behave as a coherent unit of the Alaska megathrust, the KOKA segment is characterized by semi-independent behavior. At least 2, and perhaps as many as 4, of the last 7 prehistoric great earthquakes at this plate boundary did not propagate this far west. |
format |
Article in Journal/Newspaper |
author |
Hutchinson, Ian Crowell, Aron L |
spellingShingle |
Hutchinson, Ian Crowell, Aron L Recurrence and Extent of Great Earthquakes in Southern Alaska During the Late Holocene from an Analysis of the Radiocarbon Record of Land-Level Change and Village Abandonment |
author_facet |
Hutchinson, Ian Crowell, Aron L |
author_sort |
Hutchinson, Ian |
title |
Recurrence and Extent of Great Earthquakes in Southern Alaska During the Late Holocene from an Analysis of the Radiocarbon Record of Land-Level Change and Village Abandonment |
title_short |
Recurrence and Extent of Great Earthquakes in Southern Alaska During the Late Holocene from an Analysis of the Radiocarbon Record of Land-Level Change and Village Abandonment |
title_full |
Recurrence and Extent of Great Earthquakes in Southern Alaska During the Late Holocene from an Analysis of the Radiocarbon Record of Land-Level Change and Village Abandonment |
title_fullStr |
Recurrence and Extent of Great Earthquakes in Southern Alaska During the Late Holocene from an Analysis of the Radiocarbon Record of Land-Level Change and Village Abandonment |
title_full_unstemmed |
Recurrence and Extent of Great Earthquakes in Southern Alaska During the Late Holocene from an Analysis of the Radiocarbon Record of Land-Level Change and Village Abandonment |
title_sort |
recurrence and extent of great earthquakes in southern alaska during the late holocene from an analysis of the radiocarbon record of land-level change and village abandonment |
publisher |
Radiocarbon |
publishDate |
2007 |
url |
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/3020 |
geographic |
Gulf of Alaska |
geographic_facet |
Gulf of Alaska |
genre |
Kodiak Alaska |
genre_facet |
Kodiak Alaska |
op_source |
Radiocarbon; Vol 49, No 3 (2007); 1323-1385 0033-8222 |
op_relation |
https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/3020/2778 https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/3020 |
_version_ |
1766058996545880064 |