Field Observations and Modeling of the 1957 Earthquake and Tsunami on the Islands of the Four Mountains, Aleutian Islands, Alaska
Due to a lack of research in the Aleutian Islands, a comprehensive history of the Aleutian subduction zone is not developed; however, this study indicates that the Aleutian subduction zone is capable of generating magnitude ~9 earthquakes or larger in addition to trans-Pacific tsunamis. Comparison o...
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ftcwashingtonuni:oai:digitalcommons.cwu.edu:etd-1194 2023-05-15T18:48:50+02:00 Field Observations and Modeling of the 1957 Earthquake and Tsunami on the Islands of the Four Mountains, Aleutian Islands, Alaska Griswold, Frances R. 2015-01-01T08:00:00Z application/pdf https://digitalcommons.cwu.edu/etd/201 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1194&context=etd English eng ScholarWorks@CWU https://digitalcommons.cwu.edu/etd/201 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1194&context=etd All Master's Theses Tsunami 1957 Aleutians Alaska Earth Sciences Geology Sedimentology text 2015 ftcwashingtonuni 2022-10-20T20:23:54Z Due to a lack of research in the Aleutian Islands, a comprehensive history of the Aleutian subduction zone is not developed; however, this study indicates that the Aleutian subduction zone is capable of generating magnitude ~9 earthquakes or larger in addition to trans-Pacific tsunamis. Comparison of simulated runup and observed runup will help to determine the characteristics of rupture in the eastern Aleutians. A recent survey of the tsunami wrackline produced by the 1957 Great Aleutian earthquake (Mw 8.6) indicates runup up to 17.5 m in the Islands of the Four Mountains (presented here). Combined with other nearfield observations of 22 m on Umnak and 18.5 m on Unalaska (USGS), our measurements establish the 1957 tsunami as a significant tsunami in the 20th century. Through modeling this earthquake and tsunami and comparing simulations to nearfield observations, we conclude that the earthquake’s magnitude and amount of eastern slip are both higher than previously estimated. I propose several slip distributions that approximately recreate the observed runup; all of these distributions include high slip in the eastern portion of the aftershock zone, though the location of slip and intensity differ between models. No source model with a Mw = 8.6 was capable of generating the observed 1957 runup; the event was likely at least Mw > 8.9. Because nearfield observations are limited to those listed above, and seismic records are inadequate, a more precise solution to the rupture pattern cannot be determined. Text Alaska Aleutian Islands Central Washington University: ScholarWorks Pacific |
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Central Washington University: ScholarWorks |
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ftcwashingtonuni |
language |
English |
topic |
Tsunami 1957 Aleutians Alaska Earth Sciences Geology Sedimentology |
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Tsunami 1957 Aleutians Alaska Earth Sciences Geology Sedimentology Griswold, Frances R. Field Observations and Modeling of the 1957 Earthquake and Tsunami on the Islands of the Four Mountains, Aleutian Islands, Alaska |
topic_facet |
Tsunami 1957 Aleutians Alaska Earth Sciences Geology Sedimentology |
description |
Due to a lack of research in the Aleutian Islands, a comprehensive history of the Aleutian subduction zone is not developed; however, this study indicates that the Aleutian subduction zone is capable of generating magnitude ~9 earthquakes or larger in addition to trans-Pacific tsunamis. Comparison of simulated runup and observed runup will help to determine the characteristics of rupture in the eastern Aleutians. A recent survey of the tsunami wrackline produced by the 1957 Great Aleutian earthquake (Mw 8.6) indicates runup up to 17.5 m in the Islands of the Four Mountains (presented here). Combined with other nearfield observations of 22 m on Umnak and 18.5 m on Unalaska (USGS), our measurements establish the 1957 tsunami as a significant tsunami in the 20th century. Through modeling this earthquake and tsunami and comparing simulations to nearfield observations, we conclude that the earthquake’s magnitude and amount of eastern slip are both higher than previously estimated. I propose several slip distributions that approximately recreate the observed runup; all of these distributions include high slip in the eastern portion of the aftershock zone, though the location of slip and intensity differ between models. No source model with a Mw = 8.6 was capable of generating the observed 1957 runup; the event was likely at least Mw > 8.9. Because nearfield observations are limited to those listed above, and seismic records are inadequate, a more precise solution to the rupture pattern cannot be determined. |
format |
Text |
author |
Griswold, Frances R. |
author_facet |
Griswold, Frances R. |
author_sort |
Griswold, Frances R. |
title |
Field Observations and Modeling of the 1957 Earthquake and Tsunami on the Islands of the Four Mountains, Aleutian Islands, Alaska |
title_short |
Field Observations and Modeling of the 1957 Earthquake and Tsunami on the Islands of the Four Mountains, Aleutian Islands, Alaska |
title_full |
Field Observations and Modeling of the 1957 Earthquake and Tsunami on the Islands of the Four Mountains, Aleutian Islands, Alaska |
title_fullStr |
Field Observations and Modeling of the 1957 Earthquake and Tsunami on the Islands of the Four Mountains, Aleutian Islands, Alaska |
title_full_unstemmed |
Field Observations and Modeling of the 1957 Earthquake and Tsunami on the Islands of the Four Mountains, Aleutian Islands, Alaska |
title_sort |
field observations and modeling of the 1957 earthquake and tsunami on the islands of the four mountains, aleutian islands, alaska |
publisher |
ScholarWorks@CWU |
publishDate |
2015 |
url |
https://digitalcommons.cwu.edu/etd/201 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1194&context=etd |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Alaska Aleutian Islands |
genre_facet |
Alaska Aleutian Islands |
op_source |
All Master's Theses |
op_relation |
https://digitalcommons.cwu.edu/etd/201 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1194&context=etd |
_version_ |
1766242120889270272 |