Late Pleistocene glacial chronologies and paleoclimate in the northern Rocky Mountains
The geologic record of mountain glaciations is a robust indicator of terrestrial paleoclimate change. During the last glaciation, mountain ranges across the western US hosted glaciers while the Cordilleran and Laurentide ice sheets flowed to the west and east of the continental divide, respectively....
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ftcopernicus:oai:publications.copernicus.org:cp96792 2023-05-15T16:40:33+02:00 Late Pleistocene glacial chronologies and paleoclimate in the northern Rocky Mountains Quirk, Brendon J. Huss, Elizabeth Laabs, Benjamin J. C. Leonard, Eric Licciardi, Joseph Plummer, Mitchell A. Caffee, Marc W. 2022-02-15 application/pdf https://doi.org/10.5194/cp-18-293-2022 https://cp.copernicus.org/articles/18/293/2022/ eng eng doi:10.5194/cp-18-293-2022 https://cp.copernicus.org/articles/18/293/2022/ eISSN: 1814-9332 Text 2022 ftcopernicus https://doi.org/10.5194/cp-18-293-2022 2022-02-21T17:22:16Z The geologic record of mountain glaciations is a robust indicator of terrestrial paleoclimate change. During the last glaciation, mountain ranges across the western US hosted glaciers while the Cordilleran and Laurentide ice sheets flowed to the west and east of the continental divide, respectively. Records detailing the chronologies and paleoclimate significance of these ice advances have been developed for many sites across North America. However, relatively few glacial records have been developed for mountain glaciers in the northern Rocky Mountains near former ice sheet margins. Here, we report cosmogenic beryllium-10 surface exposure ages and numerical glacier modeling results, which show that mountain glaciers in the northern Rockies abandoned terminal moraines after the end of the global Last Glacial Maximum around 17–18 ka and could have been sustained by − 10 to − 8.5 ∘ C temperature depressions relative to modern assuming similar or less than modern precipitation. Additionally, we present a deglacial chronology from the northern Rocky Mountains that indicates while there is considerable variability in initial moraine abandonment ages across the Rocky Mountains, the pace of subsequent ice retreat through the late glacial exhibits some regional coherence. Our results provide insight on potential regional mechanisms driving the initiation of and sustained deglaciation in the western US, including rising atmospheric CO 2 and ice sheet collapse. Text Ice Sheet Copernicus Publications: E-Journals Northern Rockies ENVELOPE(-123.446,-123.446,59.074,59.074) Climate of the Past 18 2 293 312 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
The geologic record of mountain glaciations is a robust indicator of terrestrial paleoclimate change. During the last glaciation, mountain ranges across the western US hosted glaciers while the Cordilleran and Laurentide ice sheets flowed to the west and east of the continental divide, respectively. Records detailing the chronologies and paleoclimate significance of these ice advances have been developed for many sites across North America. However, relatively few glacial records have been developed for mountain glaciers in the northern Rocky Mountains near former ice sheet margins. Here, we report cosmogenic beryllium-10 surface exposure ages and numerical glacier modeling results, which show that mountain glaciers in the northern Rockies abandoned terminal moraines after the end of the global Last Glacial Maximum around 17–18 ka and could have been sustained by − 10 to − 8.5 ∘ C temperature depressions relative to modern assuming similar or less than modern precipitation. Additionally, we present a deglacial chronology from the northern Rocky Mountains that indicates while there is considerable variability in initial moraine abandonment ages across the Rocky Mountains, the pace of subsequent ice retreat through the late glacial exhibits some regional coherence. Our results provide insight on potential regional mechanisms driving the initiation of and sustained deglaciation in the western US, including rising atmospheric CO 2 and ice sheet collapse. |
format |
Text |
author |
Quirk, Brendon J. Huss, Elizabeth Laabs, Benjamin J. C. Leonard, Eric Licciardi, Joseph Plummer, Mitchell A. Caffee, Marc W. |
spellingShingle |
Quirk, Brendon J. Huss, Elizabeth Laabs, Benjamin J. C. Leonard, Eric Licciardi, Joseph Plummer, Mitchell A. Caffee, Marc W. Late Pleistocene glacial chronologies and paleoclimate in the northern Rocky Mountains |
author_facet |
Quirk, Brendon J. Huss, Elizabeth Laabs, Benjamin J. C. Leonard, Eric Licciardi, Joseph Plummer, Mitchell A. Caffee, Marc W. |
author_sort |
Quirk, Brendon J. |
title |
Late Pleistocene glacial chronologies and paleoclimate in the northern Rocky Mountains |
title_short |
Late Pleistocene glacial chronologies and paleoclimate in the northern Rocky Mountains |
title_full |
Late Pleistocene glacial chronologies and paleoclimate in the northern Rocky Mountains |
title_fullStr |
Late Pleistocene glacial chronologies and paleoclimate in the northern Rocky Mountains |
title_full_unstemmed |
Late Pleistocene glacial chronologies and paleoclimate in the northern Rocky Mountains |
title_sort |
late pleistocene glacial chronologies and paleoclimate in the northern rocky mountains |
publishDate |
2022 |
url |
https://doi.org/10.5194/cp-18-293-2022 https://cp.copernicus.org/articles/18/293/2022/ |
long_lat |
ENVELOPE(-123.446,-123.446,59.074,59.074) |
geographic |
Northern Rockies |
geographic_facet |
Northern Rockies |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-18-293-2022 https://cp.copernicus.org/articles/18/293/2022/ |
op_doi |
https://doi.org/10.5194/cp-18-293-2022 |
container_title |
Climate of the Past |
container_volume |
18 |
container_issue |
2 |
container_start_page |
293 |
op_container_end_page |
312 |
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1766030960861642752 |