Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska
Central Interior Alaska is one of the most seismically active regions in North America, exhibiting a high concentration of intraplate earthquakes approximately 700 km away from the southern Alaska subduction zone. Seismological evidence suggests that intraplate seismicity in the region is not unifor...
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ftmdpi:oai:mdpi.com:/2076-3263/11/3/127/ 2023-08-20T03:59:15+02:00 Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska Nilesh C. Dixit Catherine Hanks agris 2021-03-10 application/pdf https://doi.org/10.3390/geosciences11030127 EN eng Multidisciplinary Digital Publishing Institute Geophysics https://dx.doi.org/10.3390/geosciences11030127 https://creativecommons.org/licenses/by/4.0/ Geosciences; Volume 11; Issue 3; Pages: 127 potential field modeling interior Alaska transtensional basin foreland basin seismic interpretation Text 2021 ftmdpi https://doi.org/10.3390/geosciences11030127 2023-08-01T01:14:48Z Central Interior Alaska is one of the most seismically active regions in North America, exhibiting a high concentration of intraplate earthquakes approximately 700 km away from the southern Alaska subduction zone. Seismological evidence suggests that intraplate seismicity in the region is not uniformly distributed, but concentrated in several discrete seismic zones, including the Nenana basin and the adjacent Tanana basin. Although the location and magnitude of the seismic activity in both basins are well defined by a network of seismic stations in the region, the tectonic controls on these intraplate earthquakes and the heterogeneous nature of Alaska’s continental interior remain poorly understood. We investigated the crustal structure of the Nenana and Tanana basins using available seismic reflection, aeromagnetic and gravity anomaly data, supplemented by geophysical well logs and outcrop data. We developed nine new two-dimensional forward models to delineate internal geometries and the crustal structure of Alaska’s interior. The results of our study demonstrates a strong crustal heterogeneity beneath both basins. The Tanana basin is a relatively shallow (up to 2 km) asymmetrical foreland basin with its southern, deeper side controlled by the northern foothills of the Central Alaska Range. Northeast-trending left lateral strike-slip faults within the Tanana basin are interpreted as a zone of clockwise crustal block rotation. The Nenana basin has a fundamentally different geometry. It is a deep (up to 8 km), narrow transtensional pull-apart basin that is deforming along the left-lateral Minto Fault. This study identifies two distinct modes of current tectonic deformation in Central Interior Alaska and provides a basis for modeling the interplay between intraplate stress fields and major structural features that potentially influence the generation of intraplate earthquakes in the region. Text alaska range Alaska MDPI Open Access Publishing Northern Foothills ENVELOPE(163.917,163.917,-74.733,-74.733) Geosciences 11 3 127 |
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MDPI Open Access Publishing |
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ftmdpi |
language |
English |
topic |
potential field modeling interior Alaska transtensional basin foreland basin seismic interpretation |
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potential field modeling interior Alaska transtensional basin foreland basin seismic interpretation Nilesh C. Dixit Catherine Hanks Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
topic_facet |
potential field modeling interior Alaska transtensional basin foreland basin seismic interpretation |
description |
Central Interior Alaska is one of the most seismically active regions in North America, exhibiting a high concentration of intraplate earthquakes approximately 700 km away from the southern Alaska subduction zone. Seismological evidence suggests that intraplate seismicity in the region is not uniformly distributed, but concentrated in several discrete seismic zones, including the Nenana basin and the adjacent Tanana basin. Although the location and magnitude of the seismic activity in both basins are well defined by a network of seismic stations in the region, the tectonic controls on these intraplate earthquakes and the heterogeneous nature of Alaska’s continental interior remain poorly understood. We investigated the crustal structure of the Nenana and Tanana basins using available seismic reflection, aeromagnetic and gravity anomaly data, supplemented by geophysical well logs and outcrop data. We developed nine new two-dimensional forward models to delineate internal geometries and the crustal structure of Alaska’s interior. The results of our study demonstrates a strong crustal heterogeneity beneath both basins. The Tanana basin is a relatively shallow (up to 2 km) asymmetrical foreland basin with its southern, deeper side controlled by the northern foothills of the Central Alaska Range. Northeast-trending left lateral strike-slip faults within the Tanana basin are interpreted as a zone of clockwise crustal block rotation. The Nenana basin has a fundamentally different geometry. It is a deep (up to 8 km), narrow transtensional pull-apart basin that is deforming along the left-lateral Minto Fault. This study identifies two distinct modes of current tectonic deformation in Central Interior Alaska and provides a basis for modeling the interplay between intraplate stress fields and major structural features that potentially influence the generation of intraplate earthquakes in the region. |
format |
Text |
author |
Nilesh C. Dixit Catherine Hanks |
author_facet |
Nilesh C. Dixit Catherine Hanks |
author_sort |
Nilesh C. Dixit |
title |
Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
title_short |
Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
title_full |
Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
title_fullStr |
Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
title_full_unstemmed |
Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
title_sort |
basement structure and styles of active tectonic deformation in central interior alaska |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2021 |
url |
https://doi.org/10.3390/geosciences11030127 |
op_coverage |
agris |
long_lat |
ENVELOPE(163.917,163.917,-74.733,-74.733) |
geographic |
Northern Foothills |
geographic_facet |
Northern Foothills |
genre |
alaska range Alaska |
genre_facet |
alaska range Alaska |
op_source |
Geosciences; Volume 11; Issue 3; Pages: 127 |
op_relation |
Geophysics https://dx.doi.org/10.3390/geosciences11030127 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/geosciences11030127 |
container_title |
Geosciences |
container_volume |
11 |
container_issue |
3 |
container_start_page |
127 |
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