Uplift and Subsidence Reveal a Nonpersistent Megathrust Rupture Boundary (Sitkinak Island, Alaska)
We report stratigraphic evidence of land-level change and tsunami inundation along the Alaska-Aleutian megathrust during prehistoric and historical earthquakes west of Kodiak Island. On Sitkinak Island, cores and tidal outcrops fringing a lagoon reveal five sharp lithologic contacts that record cose...
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ftunivrhodeislan:oai:digitalcommons.uri.edu:geo_facpubs-1005 2024-09-15T18:16:54+00:00 Uplift and Subsidence Reveal a Nonpersistent Megathrust Rupture Boundary (Sitkinak Island, Alaska) Briggs, Richard W. Engelhart, Simon E. Nelson, Alan R. Dura, Tina Kemp, Andrew C. Haeussler, Peter J. Corbett, D. Reide Angster, Stephen J. Bradley, Lee-Ann 2014-04-14T07:00:00Z application/pdf https://digitalcommons.uri.edu/geo_facpubs/6 https://doi.org/10.1002/2014GL059380 https://digitalcommons.uri.edu/context/geo_facpubs/article/1005/viewcontent/Briggs_et_al_2014_Geophysical_Research_Letters.pdf unknown DigitalCommons@URI https://digitalcommons.uri.edu/geo_facpubs/6 doi:10.1002/2014GL059380 https://digitalcommons.uri.edu/context/geo_facpubs/article/1005/viewcontent/Briggs_et_al_2014_Geophysical_Research_Letters.pdf Geosciences Faculty Publications text 2014 ftunivrhodeislan https://doi.org/10.1002/2014GL059380 2024-08-21T00:09:33Z We report stratigraphic evidence of land-level change and tsunami inundation along the Alaska-Aleutian megathrust during prehistoric and historical earthquakes west of Kodiak Island. On Sitkinak Island, cores and tidal outcrops fringing a lagoon reveal five sharp lithologic contacts that record coseismic land-level change. Radiocarbon dates, 137Cs profiles, computerized tomography scans, and microfossil assemblages are consistent with rapid uplift circa 290–0, 520–300, and 1050–790 cal yr B.P. and subsidence in A.D. 1964 and circa 640–510 cal yr B.P. Radiocarbon, 137Cs, and 210Pb ages bracketing a sand bed traced 1.5 km inland and evidence for sudden uplift are consistent with Russian accounts of an earthquake and tsunami in A.D. 1788. The mixed uplift and subsidence record suggests that Sitkinak Island sits above a nonpersistent boundary near the southwestern limit of the A.D. 1964 Mw 9.2 megathrust rupture. Text Kodiak Alaska University of Rhode Island: DigitalCommons@URI Geophysical Research Letters 41 7 2289 2296 |
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Open Polar |
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University of Rhode Island: DigitalCommons@URI |
op_collection_id |
ftunivrhodeislan |
language |
unknown |
description |
We report stratigraphic evidence of land-level change and tsunami inundation along the Alaska-Aleutian megathrust during prehistoric and historical earthquakes west of Kodiak Island. On Sitkinak Island, cores and tidal outcrops fringing a lagoon reveal five sharp lithologic contacts that record coseismic land-level change. Radiocarbon dates, 137Cs profiles, computerized tomography scans, and microfossil assemblages are consistent with rapid uplift circa 290–0, 520–300, and 1050–790 cal yr B.P. and subsidence in A.D. 1964 and circa 640–510 cal yr B.P. Radiocarbon, 137Cs, and 210Pb ages bracketing a sand bed traced 1.5 km inland and evidence for sudden uplift are consistent with Russian accounts of an earthquake and tsunami in A.D. 1788. The mixed uplift and subsidence record suggests that Sitkinak Island sits above a nonpersistent boundary near the southwestern limit of the A.D. 1964 Mw 9.2 megathrust rupture. |
format |
Text |
author |
Briggs, Richard W. Engelhart, Simon E. Nelson, Alan R. Dura, Tina Kemp, Andrew C. Haeussler, Peter J. Corbett, D. Reide Angster, Stephen J. Bradley, Lee-Ann |
spellingShingle |
Briggs, Richard W. Engelhart, Simon E. Nelson, Alan R. Dura, Tina Kemp, Andrew C. Haeussler, Peter J. Corbett, D. Reide Angster, Stephen J. Bradley, Lee-Ann Uplift and Subsidence Reveal a Nonpersistent Megathrust Rupture Boundary (Sitkinak Island, Alaska) |
author_facet |
Briggs, Richard W. Engelhart, Simon E. Nelson, Alan R. Dura, Tina Kemp, Andrew C. Haeussler, Peter J. Corbett, D. Reide Angster, Stephen J. Bradley, Lee-Ann |
author_sort |
Briggs, Richard W. |
title |
Uplift and Subsidence Reveal a Nonpersistent Megathrust Rupture Boundary (Sitkinak Island, Alaska) |
title_short |
Uplift and Subsidence Reveal a Nonpersistent Megathrust Rupture Boundary (Sitkinak Island, Alaska) |
title_full |
Uplift and Subsidence Reveal a Nonpersistent Megathrust Rupture Boundary (Sitkinak Island, Alaska) |
title_fullStr |
Uplift and Subsidence Reveal a Nonpersistent Megathrust Rupture Boundary (Sitkinak Island, Alaska) |
title_full_unstemmed |
Uplift and Subsidence Reveal a Nonpersistent Megathrust Rupture Boundary (Sitkinak Island, Alaska) |
title_sort |
uplift and subsidence reveal a nonpersistent megathrust rupture boundary (sitkinak island, alaska) |
publisher |
DigitalCommons@URI |
publishDate |
2014 |
url |
https://digitalcommons.uri.edu/geo_facpubs/6 https://doi.org/10.1002/2014GL059380 https://digitalcommons.uri.edu/context/geo_facpubs/article/1005/viewcontent/Briggs_et_al_2014_Geophysical_Research_Letters.pdf |
genre |
Kodiak Alaska |
genre_facet |
Kodiak Alaska |
op_source |
Geosciences Faculty Publications |
op_relation |
https://digitalcommons.uri.edu/geo_facpubs/6 doi:10.1002/2014GL059380 https://digitalcommons.uri.edu/context/geo_facpubs/article/1005/viewcontent/Briggs_et_al_2014_Geophysical_Research_Letters.pdf |
op_doi |
https://doi.org/10.1002/2014GL059380 |
container_title |
Geophysical Research Letters |
container_volume |
41 |
container_issue |
7 |
container_start_page |
2289 |
op_container_end_page |
2296 |
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1810454898977800192 |