Imaging Crustal Structure in Alaska from Receiver Functions
Alaska is bounded by an active subduction zone in the south where the Pacific plate has been colliding with and subducting under the northwestern edge of the North American Plate. The Denali fault across central Alaska separates complex accreted terranes in the south from older terranes and the stab...
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ftunivhouston:oai:uh-ir.tdl.org:10657/3406 2023-05-15T13:09:40+02:00 Imaging Crustal Structure in Alaska from Receiver Functions Zhang, Ying 1994- Li, Aibing Suppe, John Li, Lun May 2018 application/pdf born digital http://hdl.handle.net/10657/3406 en eng http://hdl.handle.net/10657/3406 The author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s). Alaska Crust Thesis Text 2018 ftunivhouston 2022-10-29T22:08:08Z Alaska is bounded by an active subduction zone in the south where the Pacific plate has been colliding with and subducting under the northwestern edge of the North American Plate. The Denali fault across central Alaska separates complex accreted terranes in the south from older terranes and the stable North American continent in the north. In this thesis, we present a broad-scale image of mean crustal thickness and Vp/Vs ratio across the major tectonic domains of Alaska based on P wave receiver functions. We have processed seismograms from 174 earthquakes at 110 stations of the USArray Transportable Array and Alaska Regional Network. Individual receiver functions are stacked by station with moveout correction and by the H-k method. Both methods produce similar Moho depth variation of 28 km to 46 km across Alaska. The deepest Moho up to 46 km is located in southern Alaska beneath the Alaska Range and Wrangell - St. Elias Mountains. A thick crust of 38-43 km is also imaged near the Arctic margin in northern Alaska at the Brooks Range. In contrast, the Moho of central Alaska is generally shallow, at 33 km depth on average, except beneath the W. Mackenzie Mountains. Relatively thin crust is also located beneath lowland areas such as the North America craton, the Nanana Basin, and Cook Inlet. Vp/Vs ratios of the crust are estimated at each station from the H-k method. Normal to slightly low Vp/Vs ratios are located to the north of the Denali fault with a range of 1.65-1.75. High Vp/Vs ratios are found in southern Alaska with an average value of 1.85, which can be attributed to broad volcanism in the area. The highest Vp/Vs ratio of 2.1 is in the Wrangell volcanic field, which is caused by metamorphic and mafic intrusive rocks. Relatively high Vp/Vs ratio also exists at other volcanoes in southwest Alaska and the Alaska Range. Earth and Atmospheric Sciences, Department of Thesis alaska range Arctic Brooks Range Mackenzie mountains Alaska University of Houston Institutional Repository (UHIR) Arctic Pacific |
institution |
Open Polar |
collection |
University of Houston Institutional Repository (UHIR) |
op_collection_id |
ftunivhouston |
language |
English |
topic |
Alaska Crust |
spellingShingle |
Alaska Crust Zhang, Ying 1994- Imaging Crustal Structure in Alaska from Receiver Functions |
topic_facet |
Alaska Crust |
description |
Alaska is bounded by an active subduction zone in the south where the Pacific plate has been colliding with and subducting under the northwestern edge of the North American Plate. The Denali fault across central Alaska separates complex accreted terranes in the south from older terranes and the stable North American continent in the north. In this thesis, we present a broad-scale image of mean crustal thickness and Vp/Vs ratio across the major tectonic domains of Alaska based on P wave receiver functions. We have processed seismograms from 174 earthquakes at 110 stations of the USArray Transportable Array and Alaska Regional Network. Individual receiver functions are stacked by station with moveout correction and by the H-k method. Both methods produce similar Moho depth variation of 28 km to 46 km across Alaska. The deepest Moho up to 46 km is located in southern Alaska beneath the Alaska Range and Wrangell - St. Elias Mountains. A thick crust of 38-43 km is also imaged near the Arctic margin in northern Alaska at the Brooks Range. In contrast, the Moho of central Alaska is generally shallow, at 33 km depth on average, except beneath the W. Mackenzie Mountains. Relatively thin crust is also located beneath lowland areas such as the North America craton, the Nanana Basin, and Cook Inlet. Vp/Vs ratios of the crust are estimated at each station from the H-k method. Normal to slightly low Vp/Vs ratios are located to the north of the Denali fault with a range of 1.65-1.75. High Vp/Vs ratios are found in southern Alaska with an average value of 1.85, which can be attributed to broad volcanism in the area. The highest Vp/Vs ratio of 2.1 is in the Wrangell volcanic field, which is caused by metamorphic and mafic intrusive rocks. Relatively high Vp/Vs ratio also exists at other volcanoes in southwest Alaska and the Alaska Range. Earth and Atmospheric Sciences, Department of |
author2 |
Li, Aibing Suppe, John Li, Lun |
format |
Thesis |
author |
Zhang, Ying 1994- |
author_facet |
Zhang, Ying 1994- |
author_sort |
Zhang, Ying 1994- |
title |
Imaging Crustal Structure in Alaska from Receiver Functions |
title_short |
Imaging Crustal Structure in Alaska from Receiver Functions |
title_full |
Imaging Crustal Structure in Alaska from Receiver Functions |
title_fullStr |
Imaging Crustal Structure in Alaska from Receiver Functions |
title_full_unstemmed |
Imaging Crustal Structure in Alaska from Receiver Functions |
title_sort |
imaging crustal structure in alaska from receiver functions |
publishDate |
2018 |
url |
http://hdl.handle.net/10657/3406 |
geographic |
Arctic Pacific |
geographic_facet |
Arctic Pacific |
genre |
alaska range Arctic Brooks Range Mackenzie mountains Alaska |
genre_facet |
alaska range Arctic Brooks Range Mackenzie mountains Alaska |
op_relation |
http://hdl.handle.net/10657/3406 |
op_rights |
The author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s). |
_version_ |
1766192260002611200 |