Modeling North American Freshwater Runoff through the Last Glacial Cycle
The Northern Hemisphere ice sheets decayed rapidly during deglacial phases of the ice-age cycle, producing meltwater fluxes that may have been of sufficient magnitude to perturb oceanic circulation. The continental record of ice-sheet history is more obscured during the growth and advance of the las...
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Cambridge University Press (CUP)
1999
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crcambridgeupr:10.1006/qres.1999.2079 2024-06-09T07:46:47+00:00 Modeling North American Freshwater Runoff through the Last Glacial Cycle Marshall, Shawn J. Clarke, Garry K.C. 1999 http://dx.doi.org/10.1006/qres.1999.2079 http://api.elsevier.com/content/article/PII:S0033589499920793?httpAccept=text/xml http://api.elsevier.com/content/article/PII:S0033589499920793?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400025916 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Quaternary Research volume 52, issue 3, page 300-315 ISSN 0033-5894 1096-0287 journal-article 1999 crcambridgeupr https://doi.org/10.1006/qres.1999.2079 2024-05-15T13:06:18Z The Northern Hemisphere ice sheets decayed rapidly during deglacial phases of the ice-age cycle, producing meltwater fluxes that may have been of sufficient magnitude to perturb oceanic circulation. The continental record of ice-sheet history is more obscured during the growth and advance of the last great ice sheets, ca. 120,000–20,000 yr B.P., but ice cores tell of high-amplitude, millennial-scale climate fluctuations that prevailed throughout this period. These climatic excursions would have provoked significant fluctuation of ice-sheet margins and runoff variability whenever ice sheets extended to mid-latitudes, giving a complex pattern of freshwater delivery to the oceans. A model of continental surface hydrology is coupled with an ice-dynamics model simulating the last glacial cycle in North America. Meltwater discharged from ice sheets is either channeled down continental drainage pathways or stored temporarily in large systems of proglacial lakes that border the retreating ice-sheet margin. The coupled treatment provides quantitative estimates of the spatial and temporal patterns of freshwater flux to the continental margins. Results imply an intensified surface hydrological environment when ice sheets are present, despite a net decrease in precipitation during glacial periods. Diminished continental evaporation and high levels of meltwater production combine to give mid-latitude runoff values that are highly variable through the glacial cycle, but are two to three times in excess of modern river fluxes; drainage to the North Atlantic via the St. Lawrence, Hudson, and Mississippi River catchments averages 0.356 Sv for the period 60,000–10,000 yr B.P., compared to 0.122 Sv for the past 10,000 yr. High-amplitude meltwater pulses to the Gulf of Mexico, North Atlantic, and North Pacific occur throughout the glacial period, with ice-sheet geometry controlling intricate patterns of freshwater routing variability. Runoff from North America is staged in the final deglaciation, with a stepped sequence of pulses ... Article in Journal/Newspaper Ice Sheet North Atlantic Cambridge University Press Hudson Pacific Quaternary Research 52 3 300 315 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
The Northern Hemisphere ice sheets decayed rapidly during deglacial phases of the ice-age cycle, producing meltwater fluxes that may have been of sufficient magnitude to perturb oceanic circulation. The continental record of ice-sheet history is more obscured during the growth and advance of the last great ice sheets, ca. 120,000–20,000 yr B.P., but ice cores tell of high-amplitude, millennial-scale climate fluctuations that prevailed throughout this period. These climatic excursions would have provoked significant fluctuation of ice-sheet margins and runoff variability whenever ice sheets extended to mid-latitudes, giving a complex pattern of freshwater delivery to the oceans. A model of continental surface hydrology is coupled with an ice-dynamics model simulating the last glacial cycle in North America. Meltwater discharged from ice sheets is either channeled down continental drainage pathways or stored temporarily in large systems of proglacial lakes that border the retreating ice-sheet margin. The coupled treatment provides quantitative estimates of the spatial and temporal patterns of freshwater flux to the continental margins. Results imply an intensified surface hydrological environment when ice sheets are present, despite a net decrease in precipitation during glacial periods. Diminished continental evaporation and high levels of meltwater production combine to give mid-latitude runoff values that are highly variable through the glacial cycle, but are two to three times in excess of modern river fluxes; drainage to the North Atlantic via the St. Lawrence, Hudson, and Mississippi River catchments averages 0.356 Sv for the period 60,000–10,000 yr B.P., compared to 0.122 Sv for the past 10,000 yr. High-amplitude meltwater pulses to the Gulf of Mexico, North Atlantic, and North Pacific occur throughout the glacial period, with ice-sheet geometry controlling intricate patterns of freshwater routing variability. Runoff from North America is staged in the final deglaciation, with a stepped sequence of pulses ... |
format |
Article in Journal/Newspaper |
author |
Marshall, Shawn J. Clarke, Garry K.C. |
spellingShingle |
Marshall, Shawn J. Clarke, Garry K.C. Modeling North American Freshwater Runoff through the Last Glacial Cycle |
author_facet |
Marshall, Shawn J. Clarke, Garry K.C. |
author_sort |
Marshall, Shawn J. |
title |
Modeling North American Freshwater Runoff through the Last Glacial Cycle |
title_short |
Modeling North American Freshwater Runoff through the Last Glacial Cycle |
title_full |
Modeling North American Freshwater Runoff through the Last Glacial Cycle |
title_fullStr |
Modeling North American Freshwater Runoff through the Last Glacial Cycle |
title_full_unstemmed |
Modeling North American Freshwater Runoff through the Last Glacial Cycle |
title_sort |
modeling north american freshwater runoff through the last glacial cycle |
publisher |
Cambridge University Press (CUP) |
publishDate |
1999 |
url |
http://dx.doi.org/10.1006/qres.1999.2079 http://api.elsevier.com/content/article/PII:S0033589499920793?httpAccept=text/xml http://api.elsevier.com/content/article/PII:S0033589499920793?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400025916 |
geographic |
Hudson Pacific |
geographic_facet |
Hudson Pacific |
genre |
Ice Sheet North Atlantic |
genre_facet |
Ice Sheet North Atlantic |
op_source |
Quaternary Research volume 52, issue 3, page 300-315 ISSN 0033-5894 1096-0287 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1006/qres.1999.2079 |
container_title |
Quaternary Research |
container_volume |
52 |
container_issue |
3 |
container_start_page |
300 |
op_container_end_page |
315 |
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1801376767714263040 |