THE DURATION AND MAGNITUDE OF FRESHWATER FLOODING EVENTS 11.4 AND 13.0 ka BP AS INFERRED FROM PALEO‐SALINITY VARIATIONS IN THE CHAMPLAIN SEA
Freshwater fluxes into the North Atlantic are known to have caused catastrophic shifts in climate by weakening the formation of North Atlantic Deep Water (NADW). During the end of the last glacial period, several large freshening events were recorded in the geologic record within the Champlain Sea,...
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ftpennstate:OAI:PSUETD:ETD-3909 2023-05-15T17:13:52+02:00 THE DURATION AND MAGNITUDE OF FRESHWATER FLOODING EVENTS 11.4 AND 13.0 ka BP AS INFERRED FROM PALEO‐SALINITY VARIATIONS IN THE CHAMPLAIN SEA Katz, Brandon Glenna Dr. Ray Najjar Dr. Michael Mann Dr. Thomas Cronin 2009-05-17 application/pdf http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-3909/index.html en eng Penn State WorldWide Copyright information available at source archive http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-3909/index.html Meteorology text 2009 ftpennstate 2011-09-13T08:34:12Z Freshwater fluxes into the North Atlantic are known to have caused catastrophic shifts in climate by weakening the formation of North Atlantic Deep Water (NADW). During the end of the last glacial period, several large freshening events were recorded in the geologic record within the Champlain Sea, indicating that large volumes of freshwater from pro-glacial lakes, such as Lake Agassiz and others in the Great Lakes Region, likely routed out into the North Atlantic. This study utilizes a two-dimensional estuarine model of the Champlain Sea during two flood events at 11.4 and 13.0 ka BP to estimate the durations and magnitudes of these freshwater flooding events, the later being of particular note as it closely predates the Younger Dryas cooling episode. Values of pre and post-flood paleo-salinity within the current-day Lake Champlain are used as constraints within the model to determine the amount and duration of freshwater fluxes required to cause the observed salinity changes. Paleo-salinity during the 11.4 ka BP event changed from 25 ppt to 8 ± 3 ppt, which requires flood volumes in excess of 5,500 km3 to inundate the region over timescales of less than two weeks. The model could not reproduce the observed freshening of the Champlain Sea (25 to 0 ± 3 ppt) for reasonable flood volumes, which may reflect model limitations in strongly sloping bathymetry and narrow channels, as well as uncertainties in the bathymetric reconstruction. These constraints on the fluxes of freshwater into the North Atlantic are useful in understanding what may have caused partial or total shutdowns of NADW during the end of the last ice age. Text NADW North Atlantic Deep Water North Atlantic PennState: Electronic Theses and Dissertations (eTD) |
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PennState: Electronic Theses and Dissertations (eTD) |
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language |
English |
topic |
Meteorology |
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Meteorology Katz, Brandon Glenna THE DURATION AND MAGNITUDE OF FRESHWATER FLOODING EVENTS 11.4 AND 13.0 ka BP AS INFERRED FROM PALEO‐SALINITY VARIATIONS IN THE CHAMPLAIN SEA |
topic_facet |
Meteorology |
description |
Freshwater fluxes into the North Atlantic are known to have caused catastrophic shifts in climate by weakening the formation of North Atlantic Deep Water (NADW). During the end of the last glacial period, several large freshening events were recorded in the geologic record within the Champlain Sea, indicating that large volumes of freshwater from pro-glacial lakes, such as Lake Agassiz and others in the Great Lakes Region, likely routed out into the North Atlantic. This study utilizes a two-dimensional estuarine model of the Champlain Sea during two flood events at 11.4 and 13.0 ka BP to estimate the durations and magnitudes of these freshwater flooding events, the later being of particular note as it closely predates the Younger Dryas cooling episode. Values of pre and post-flood paleo-salinity within the current-day Lake Champlain are used as constraints within the model to determine the amount and duration of freshwater fluxes required to cause the observed salinity changes. Paleo-salinity during the 11.4 ka BP event changed from 25 ppt to 8 ± 3 ppt, which requires flood volumes in excess of 5,500 km3 to inundate the region over timescales of less than two weeks. The model could not reproduce the observed freshening of the Champlain Sea (25 to 0 ± 3 ppt) for reasonable flood volumes, which may reflect model limitations in strongly sloping bathymetry and narrow channels, as well as uncertainties in the bathymetric reconstruction. These constraints on the fluxes of freshwater into the North Atlantic are useful in understanding what may have caused partial or total shutdowns of NADW during the end of the last ice age. |
author2 |
Dr. Ray Najjar Dr. Michael Mann Dr. Thomas Cronin |
format |
Text |
author |
Katz, Brandon Glenna |
author_facet |
Katz, Brandon Glenna |
author_sort |
Katz, Brandon Glenna |
title |
THE DURATION AND MAGNITUDE OF FRESHWATER FLOODING EVENTS 11.4 AND 13.0 ka BP AS INFERRED FROM PALEO‐SALINITY VARIATIONS IN THE CHAMPLAIN SEA |
title_short |
THE DURATION AND MAGNITUDE OF FRESHWATER FLOODING EVENTS 11.4 AND 13.0 ka BP AS INFERRED FROM PALEO‐SALINITY VARIATIONS IN THE CHAMPLAIN SEA |
title_full |
THE DURATION AND MAGNITUDE OF FRESHWATER FLOODING EVENTS 11.4 AND 13.0 ka BP AS INFERRED FROM PALEO‐SALINITY VARIATIONS IN THE CHAMPLAIN SEA |
title_fullStr |
THE DURATION AND MAGNITUDE OF FRESHWATER FLOODING EVENTS 11.4 AND 13.0 ka BP AS INFERRED FROM PALEO‐SALINITY VARIATIONS IN THE CHAMPLAIN SEA |
title_full_unstemmed |
THE DURATION AND MAGNITUDE OF FRESHWATER FLOODING EVENTS 11.4 AND 13.0 ka BP AS INFERRED FROM PALEO‐SALINITY VARIATIONS IN THE CHAMPLAIN SEA |
title_sort |
duration and magnitude of freshwater flooding events 11.4 and 13.0 ka bp as inferred from paleo‐salinity variations in the champlain sea |
publisher |
Penn State |
publishDate |
2009 |
url |
http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-3909/index.html |
genre |
NADW North Atlantic Deep Water North Atlantic |
genre_facet |
NADW North Atlantic Deep Water North Atlantic |
op_source |
http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-3909/index.html |
op_rights |
WorldWide Copyright information available at source archive |
_version_ |
1766071056954556416 |