Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska
Sediment storage in and release from the Granite Creek catchment over Holocene timescales is modulated by the fluctuations of Tana Glacier, which periodically blocks the outlet of Granite Creek. Little Ice Age expansion from 1500-1900 AD is suggested by lichenometric ages of alpine glacial moraines...
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ftoregonstate:ir.library.oregonstate.edu:3484zk85d 2024-04-21T08:02:23+00:00 Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska Blair, Mehgan O'Hearn Meigs, Dr. Andrew Geosciences Oregon State University. Graduate School https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/3484zk85d English [eng] eng unknown Oregon State University https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/3484zk85d All rights reserved Glacial landforms -- Alaska -- Wrangell-Saint Elias National Park and Preserve Glaciers -- Alaska -- Wrangell-Saint Elias National Park and Preserve Sediment transport -- Alaska -- Wrangell-Saint Elias National Park and Preserve Drift -- Alaska -- Wrangell-Saint Elias National Park and Preserve Sedimentation and deposition -- Alaska -- Wrangell-Saint Elias National Park and Preserve Dissertation ftoregonstate 2024-03-28T01:31:21Z Sediment storage in and release from the Granite Creek catchment over Holocene timescales is modulated by the fluctuations of Tana Glacier, which periodically blocks the outlet of Granite Creek. Little Ice Age expansion from 1500-1900 AD is suggested by lichenometric ages of alpine glacial moraines within Granite Creek valley. Trimlines above the Tana Glacier terminus indicate that, during this period, ice was at least 120 m thicker in the Tana Valley. According to the elevation of shorelines within the valley, the resultant ice-dammed lake occupied 50 km2 in the lower -10 km of Granite Creek valley, contained 5.9 km3 of water, and was at least 90 m deep at its maximum. Removal of the ice dam occurred during twentieth century thinning of Tana Glacier and caused a 100-m drop in the base level of Granite Creek, driving evacuation of lacustrine valley fill. The reestablishment of the fluvial system was characterized by lateral migration of Granite Creek and formation of a series of paired terraces, indicating a on-catastrophic and possibly seasonal drainage of the lake. Roughly 1.3 x 10" ms of stored sediment has been removed from the basin since drainage of the lake. Radiocarbon ages within the valley fill reveal an unconformity between overlying sediment deposited during the Little Ice Age and underlying, older sediment dating to --900 yrs B.P. Two episodes of impoundment and lacustrine deposition in the basin occurred during the mid-late Holocene and may have been separated by a period of incomplete evacuation of the valley fill. These observations reveal that sediment production within, and sediment delivery gut of this catchment are out of phase, which is characteristic of paraglacial landscape response following deglaciation. In southern Alaska, paraglacial landscape adjustment may explain the discrepancy between erosion rates estimated from short-term sediment yields and those from long-term exhumation rates. It is clear that the interpretation of sediment yields requires consideration of all sources of ... Doctoral or Postdoctoral Thesis glacier glaciers Alaska ScholarsArchive@OSU (Oregon State University) |
institution |
Open Polar |
collection |
ScholarsArchive@OSU (Oregon State University) |
op_collection_id |
ftoregonstate |
language |
English unknown |
topic |
Glacial landforms -- Alaska -- Wrangell-Saint Elias National Park and Preserve Glaciers -- Alaska -- Wrangell-Saint Elias National Park and Preserve Sediment transport -- Alaska -- Wrangell-Saint Elias National Park and Preserve Drift -- Alaska -- Wrangell-Saint Elias National Park and Preserve Sedimentation and deposition -- Alaska -- Wrangell-Saint Elias National Park and Preserve |
spellingShingle |
Glacial landforms -- Alaska -- Wrangell-Saint Elias National Park and Preserve Glaciers -- Alaska -- Wrangell-Saint Elias National Park and Preserve Sediment transport -- Alaska -- Wrangell-Saint Elias National Park and Preserve Drift -- Alaska -- Wrangell-Saint Elias National Park and Preserve Sedimentation and deposition -- Alaska -- Wrangell-Saint Elias National Park and Preserve Blair, Mehgan O'Hearn Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska |
topic_facet |
Glacial landforms -- Alaska -- Wrangell-Saint Elias National Park and Preserve Glaciers -- Alaska -- Wrangell-Saint Elias National Park and Preserve Sediment transport -- Alaska -- Wrangell-Saint Elias National Park and Preserve Drift -- Alaska -- Wrangell-Saint Elias National Park and Preserve Sedimentation and deposition -- Alaska -- Wrangell-Saint Elias National Park and Preserve |
description |
Sediment storage in and release from the Granite Creek catchment over Holocene timescales is modulated by the fluctuations of Tana Glacier, which periodically blocks the outlet of Granite Creek. Little Ice Age expansion from 1500-1900 AD is suggested by lichenometric ages of alpine glacial moraines within Granite Creek valley. Trimlines above the Tana Glacier terminus indicate that, during this period, ice was at least 120 m thicker in the Tana Valley. According to the elevation of shorelines within the valley, the resultant ice-dammed lake occupied 50 km2 in the lower -10 km of Granite Creek valley, contained 5.9 km3 of water, and was at least 90 m deep at its maximum. Removal of the ice dam occurred during twentieth century thinning of Tana Glacier and caused a 100-m drop in the base level of Granite Creek, driving evacuation of lacustrine valley fill. The reestablishment of the fluvial system was characterized by lateral migration of Granite Creek and formation of a series of paired terraces, indicating a on-catastrophic and possibly seasonal drainage of the lake. Roughly 1.3 x 10" ms of stored sediment has been removed from the basin since drainage of the lake. Radiocarbon ages within the valley fill reveal an unconformity between overlying sediment deposited during the Little Ice Age and underlying, older sediment dating to --900 yrs B.P. Two episodes of impoundment and lacustrine deposition in the basin occurred during the mid-late Holocene and may have been separated by a period of incomplete evacuation of the valley fill. These observations reveal that sediment production within, and sediment delivery gut of this catchment are out of phase, which is characteristic of paraglacial landscape response following deglaciation. In southern Alaska, paraglacial landscape adjustment may explain the discrepancy between erosion rates estimated from short-term sediment yields and those from long-term exhumation rates. It is clear that the interpretation of sediment yields requires consideration of all sources of ... |
author2 |
Meigs, Dr. Andrew Geosciences Oregon State University. Graduate School |
format |
Doctoral or Postdoctoral Thesis |
author |
Blair, Mehgan O'Hearn |
author_facet |
Blair, Mehgan O'Hearn |
author_sort |
Blair, Mehgan O'Hearn |
title |
Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska |
title_short |
Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska |
title_full |
Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska |
title_fullStr |
Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska |
title_full_unstemmed |
Sediment storage and delivery on Holocene glacial timescales, Granite Creek, southern Alaska |
title_sort |
sediment storage and delivery on holocene glacial timescales, granite creek, southern alaska |
publisher |
Oregon State University |
url |
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/3484zk85d |
genre |
glacier glaciers Alaska |
genre_facet |
glacier glaciers Alaska |
op_relation |
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/3484zk85d |
op_rights |
All rights reserved |
_version_ |
1796942585705529344 |