Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska
Across southern Alaska the northwest directed subduction of the Pacific plate is accompanied by accretion of the Yakutat terrane to continental Alaska. This has led to high tectonic strain rates and dramatic topographic relief of more than 5000 meters within 15 km of the Gulf of Alaska coast. The gl...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20040030573 2023-05-15T16:20:22+02:00 Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska SauberRosenberg, Jeanne M. Molnia, Bruce F. Unclassified, Unlimited, Publicly available [2003] application/pdf http://hdl.handle.net/2060/20040030573 unknown Document ID: 20040030573 http://hdl.handle.net/2060/20040030573 No Copyright CASI Geosciences (General) 2003 ftnasantrs 2015-03-15T02:05:41Z Across southern Alaska the northwest directed subduction of the Pacific plate is accompanied by accretion of the Yakutat terrane to continental Alaska. This has led to high tectonic strain rates and dramatic topographic relief of more than 5000 meters within 15 km of the Gulf of Alaska coast. The glaciers of this area are extensive and include large glaciers undergoing wastage (glacier retreat and thinning) and surges. The large glacier ice mass changes perturb the tectonic rate of deformation at a variety of temporal and spatial scales. We estimated surface displacements and stresses associated with ice mass fluctuations and tectonic loading by examining GPS geodetic observations and numerical model predictions. Although the glacial fluctuations perturb the tectonic stress field, especially at shallow depths, the largest contribution to ongoing crustal deformation is horizontal tectonic strain due to plate convergence. Tectonic forces are thus the primary force responsible for major earthquakes. However, for geodetic sites located < 10-20 km from major ice mass fluctuations, the changes of the solid Earth due to ice loading and unloading are an important aspect of interpreting geodetic results. The ice changes associated with Bering Glacier s most recent surge cycle are large enough to cause discernible surface displacements. Additionally, ice mass fluctuations associated with the surge cycle can modify the short-term seismicity rates in a local region. For the thrust faulting environment of the study region a large decrease in ice load may cause an increase in seismic rate in a region close to failure whereas ice loading may inhibit thrust faulting. Other/Unknown Material glacier glaciers Yakutat Alaska NASA Technical Reports Server (NTRS) Gulf of Alaska Pacific |
institution |
Open Polar |
collection |
NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
Geosciences (General) |
spellingShingle |
Geosciences (General) SauberRosenberg, Jeanne M. Molnia, Bruce F. Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska |
topic_facet |
Geosciences (General) |
description |
Across southern Alaska the northwest directed subduction of the Pacific plate is accompanied by accretion of the Yakutat terrane to continental Alaska. This has led to high tectonic strain rates and dramatic topographic relief of more than 5000 meters within 15 km of the Gulf of Alaska coast. The glaciers of this area are extensive and include large glaciers undergoing wastage (glacier retreat and thinning) and surges. The large glacier ice mass changes perturb the tectonic rate of deformation at a variety of temporal and spatial scales. We estimated surface displacements and stresses associated with ice mass fluctuations and tectonic loading by examining GPS geodetic observations and numerical model predictions. Although the glacial fluctuations perturb the tectonic stress field, especially at shallow depths, the largest contribution to ongoing crustal deformation is horizontal tectonic strain due to plate convergence. Tectonic forces are thus the primary force responsible for major earthquakes. However, for geodetic sites located < 10-20 km from major ice mass fluctuations, the changes of the solid Earth due to ice loading and unloading are an important aspect of interpreting geodetic results. The ice changes associated with Bering Glacier s most recent surge cycle are large enough to cause discernible surface displacements. Additionally, ice mass fluctuations associated with the surge cycle can modify the short-term seismicity rates in a local region. For the thrust faulting environment of the study region a large decrease in ice load may cause an increase in seismic rate in a region close to failure whereas ice loading may inhibit thrust faulting. |
author |
SauberRosenberg, Jeanne M. Molnia, Bruce F. |
author_facet |
SauberRosenberg, Jeanne M. Molnia, Bruce F. |
author_sort |
SauberRosenberg, Jeanne M. |
title |
Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska |
title_short |
Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska |
title_full |
Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska |
title_fullStr |
Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska |
title_full_unstemmed |
Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska |
title_sort |
glacier ice mass fluctuations and fault instability in tectonically active southern alaska |
publishDate |
2003 |
url |
http://hdl.handle.net/2060/20040030573 |
op_coverage |
Unclassified, Unlimited, Publicly available |
geographic |
Gulf of Alaska Pacific |
geographic_facet |
Gulf of Alaska Pacific |
genre |
glacier glaciers Yakutat Alaska |
genre_facet |
glacier glaciers Yakutat Alaska |
op_source |
CASI |
op_relation |
Document ID: 20040030573 http://hdl.handle.net/2060/20040030573 |
op_rights |
No Copyright |
_version_ |
1766008286570610688 |