Earthquake relocations delineate discrete fault network and deformation corridor throughout Southeast Alaska and Southwest Yukon
Deformation in southeastern Alaska and southwest Yukon is governed by subduction and translation of Pacific-Yakutat plates relative to the North American plate in the St. Elias region. Despite notable historical seismicity and major regional faults, studies of the region between the Fairweather and...
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2023
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Online Access: | http://dx.doi.org/10.22541/essoar.169724925.51939945/v1 |
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crwinnower:10.22541/essoar.169724925.51939945/v1 2024-06-02T08:15:50+00:00 Earthquake relocations delineate discrete fault network and deformation corridor throughout Southeast Alaska and Southwest Yukon Biegel, Katherine M. Gosselin, Jeremy M Dettmer, Jan Colpron, Maurice Enkelmann, Eva Caine, Jonathan Saul 2023 http://dx.doi.org/10.22541/essoar.169724925.51939945/v1 unknown Authorea, Inc. posted-content 2023 crwinnower https://doi.org/10.22541/essoar.169724925.51939945/v1 2024-05-07T14:19:26Z Deformation in southeastern Alaska and southwest Yukon is governed by subduction and translation of Pacific-Yakutat plates relative to the North American plate in the St. Elias region. Despite notable historical seismicity and major regional faults, studies of the region between the Fairweather and Denali faults are complicated by glacial coverage and the remote setting. In the last decade, significant improvements have been made to the density of regional broadband seismometer networks. We relocate more than 5,000 earthquakes between 2010 and 2021 in the region of southeastern Alaska and southwestern Yukon utilizing these improved seismic networks. With reductions in catalog uncertainty, particularly in depth, we quantify the thickness of the seismogenic layer in the crust throughout the region, and locate seismicity on a shallow network of upper-crustal faults. Relocated earthquakes, combined with an updated focal-mechanism catalog, permit estimating and classifying motion of active faults. This includes mapping the Totschunda-Fairweather Connector fault, which plays an important role in explaining regional deformation, and identifying new faults like the Kathleen Lake fault. We draw similarities between our seismic observations and simplified conceptual models of regional tectonics, which describe a dominant transpressional regime and localized slip partitioning. Our results support that, as deformation in the region continues to evolve, current deformation is taking place on a well-defined network of shallow faults in the corridor between the Totschunda-Fairweather Connector and Denali faults. Other/Unknown Material Yakutat Alaska Yukon The Winnower Fairweather ENVELOPE(-61.083,-61.083,-65.017,-65.017) Kathleen ENVELOPE(-116.836,-116.836,55.617,55.617) Kathleen Lake ENVELOPE(-137.304,-137.304,60.575,60.575) Pacific The Corridor ENVELOPE(78.139,78.139,-68.582,-68.582) Yukon |
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The Winnower |
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description |
Deformation in southeastern Alaska and southwest Yukon is governed by subduction and translation of Pacific-Yakutat plates relative to the North American plate in the St. Elias region. Despite notable historical seismicity and major regional faults, studies of the region between the Fairweather and Denali faults are complicated by glacial coverage and the remote setting. In the last decade, significant improvements have been made to the density of regional broadband seismometer networks. We relocate more than 5,000 earthquakes between 2010 and 2021 in the region of southeastern Alaska and southwestern Yukon utilizing these improved seismic networks. With reductions in catalog uncertainty, particularly in depth, we quantify the thickness of the seismogenic layer in the crust throughout the region, and locate seismicity on a shallow network of upper-crustal faults. Relocated earthquakes, combined with an updated focal-mechanism catalog, permit estimating and classifying motion of active faults. This includes mapping the Totschunda-Fairweather Connector fault, which plays an important role in explaining regional deformation, and identifying new faults like the Kathleen Lake fault. We draw similarities between our seismic observations and simplified conceptual models of regional tectonics, which describe a dominant transpressional regime and localized slip partitioning. Our results support that, as deformation in the region continues to evolve, current deformation is taking place on a well-defined network of shallow faults in the corridor between the Totschunda-Fairweather Connector and Denali faults. |
format |
Other/Unknown Material |
author |
Biegel, Katherine M. Gosselin, Jeremy M Dettmer, Jan Colpron, Maurice Enkelmann, Eva Caine, Jonathan Saul |
spellingShingle |
Biegel, Katherine M. Gosselin, Jeremy M Dettmer, Jan Colpron, Maurice Enkelmann, Eva Caine, Jonathan Saul Earthquake relocations delineate discrete fault network and deformation corridor throughout Southeast Alaska and Southwest Yukon |
author_facet |
Biegel, Katherine M. Gosselin, Jeremy M Dettmer, Jan Colpron, Maurice Enkelmann, Eva Caine, Jonathan Saul |
author_sort |
Biegel, Katherine M. |
title |
Earthquake relocations delineate discrete fault network and deformation corridor throughout Southeast Alaska and Southwest Yukon |
title_short |
Earthquake relocations delineate discrete fault network and deformation corridor throughout Southeast Alaska and Southwest Yukon |
title_full |
Earthquake relocations delineate discrete fault network and deformation corridor throughout Southeast Alaska and Southwest Yukon |
title_fullStr |
Earthquake relocations delineate discrete fault network and deformation corridor throughout Southeast Alaska and Southwest Yukon |
title_full_unstemmed |
Earthquake relocations delineate discrete fault network and deformation corridor throughout Southeast Alaska and Southwest Yukon |
title_sort |
earthquake relocations delineate discrete fault network and deformation corridor throughout southeast alaska and southwest yukon |
publisher |
Authorea, Inc. |
publishDate |
2023 |
url |
http://dx.doi.org/10.22541/essoar.169724925.51939945/v1 |
long_lat |
ENVELOPE(-61.083,-61.083,-65.017,-65.017) ENVELOPE(-116.836,-116.836,55.617,55.617) ENVELOPE(-137.304,-137.304,60.575,60.575) ENVELOPE(78.139,78.139,-68.582,-68.582) |
geographic |
Fairweather Kathleen Kathleen Lake Pacific The Corridor Yukon |
geographic_facet |
Fairweather Kathleen Kathleen Lake Pacific The Corridor Yukon |
genre |
Yakutat Alaska Yukon |
genre_facet |
Yakutat Alaska Yukon |
op_doi |
https://doi.org/10.22541/essoar.169724925.51939945/v1 |
_version_ |
1800740126495604736 |