The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia
Oxygen isotope data from planktonic and benthic foraminifera, on a high-resolution age model (44 ¹⁴C dates spanning 17,400 years), document deglacial environmental change on the southeast Alaska margin (59°33.32′N, 144°9.21′W, 682 m water depth). Surface freshening (i.e., δ¹⁸O reduction of 0.8‰) beg...
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ftoregonstate:ir.library.oregonstate.edu:gb19f742q 2024-04-14T08:01:54+00:00 The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia Davies, M. H. Mix, A. C. Stoner, J. S. Addison, J. A. Jaeger, J. Finney, B. Wiest, J. https://ir.library.oregonstate.edu/concern/articles/gb19f742q English [eng] eng unknown American Geophysical Union https://ir.library.oregonstate.edu/concern/articles/gb19f742q In Copyright Article ftoregonstate 2024-03-21T15:47:26Z Oxygen isotope data from planktonic and benthic foraminifera, on a high-resolution age model (44 ¹⁴C dates spanning 17,400 years), document deglacial environmental change on the southeast Alaska margin (59°33.32′N, 144°9.21′W, 682 m water depth). Surface freshening (i.e., δ¹⁸O reduction of 0.8‰) began at 16,650 ± 170 cal years B.P. during an interval of ice proximal sedimentation, likely due to freshwater input from melting glaciers. A sharp transition to laminated hemipelagic sediments constrains retreat of regional outlet glaciers onto land circa 14,790 ± 380 cal years B.P. Abrupt warming and/or freshening of the surface ocean (i.e., additional δ¹⁸O reduction of 0.9‰) coincides with the Bølling Interstade of northern Europe and Greenland. Cooling and/or higher salinities returned during the Allerød interval, coincident with the Antarctic Cold Reversal, and continue until 11,740 ± 200 cal years B.P., when onset of warming coincides with the end of the Younger Dryas. An abrupt 1‰ reduction in benthic δ¹⁸O at 14,250 ± 290 cal years B.P. likely reflects a decrease in bottom water salinity driven by deep mixing of glacial meltwater, a regional megaflood event, or brine formation associated with sea ice. Two laminated opal-rich intervals record discrete episodes of high productivity during the last deglaciation. These events, precisely dated here at 14,790 ± 380 to 12,990 ± 190 cal years B.P. and 11,160 ± 130 to 10,750 ± 220 cal years B.P., likely correlate to similar features observed elsewhere on the margins of the North Pacific and are coeval with episodes of rapid sea level rise. Remobilization of iron from newly inundated continental shelves may have helped to fuel these episodes of elevated primary productivity and sedimentary anoxia. Article in Journal/Newspaper Antarc* Antarctic glaciers Greenland Sea ice Alaska ScholarsArchive@OSU (Oregon State University) Antarctic The Antarctic Greenland Pacific |
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Open Polar |
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ScholarsArchive@OSU (Oregon State University) |
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ftoregonstate |
language |
English unknown |
description |
Oxygen isotope data from planktonic and benthic foraminifera, on a high-resolution age model (44 ¹⁴C dates spanning 17,400 years), document deglacial environmental change on the southeast Alaska margin (59°33.32′N, 144°9.21′W, 682 m water depth). Surface freshening (i.e., δ¹⁸O reduction of 0.8‰) began at 16,650 ± 170 cal years B.P. during an interval of ice proximal sedimentation, likely due to freshwater input from melting glaciers. A sharp transition to laminated hemipelagic sediments constrains retreat of regional outlet glaciers onto land circa 14,790 ± 380 cal years B.P. Abrupt warming and/or freshening of the surface ocean (i.e., additional δ¹⁸O reduction of 0.9‰) coincides with the Bølling Interstade of northern Europe and Greenland. Cooling and/or higher salinities returned during the Allerød interval, coincident with the Antarctic Cold Reversal, and continue until 11,740 ± 200 cal years B.P., when onset of warming coincides with the end of the Younger Dryas. An abrupt 1‰ reduction in benthic δ¹⁸O at 14,250 ± 290 cal years B.P. likely reflects a decrease in bottom water salinity driven by deep mixing of glacial meltwater, a regional megaflood event, or brine formation associated with sea ice. Two laminated opal-rich intervals record discrete episodes of high productivity during the last deglaciation. These events, precisely dated here at 14,790 ± 380 to 12,990 ± 190 cal years B.P. and 11,160 ± 130 to 10,750 ± 220 cal years B.P., likely correlate to similar features observed elsewhere on the margins of the North Pacific and are coeval with episodes of rapid sea level rise. Remobilization of iron from newly inundated continental shelves may have helped to fuel these episodes of elevated primary productivity and sedimentary anoxia. |
format |
Article in Journal/Newspaper |
author |
Davies, M. H. Mix, A. C. Stoner, J. S. Addison, J. A. Jaeger, J. Finney, B. Wiest, J. |
spellingShingle |
Davies, M. H. Mix, A. C. Stoner, J. S. Addison, J. A. Jaeger, J. Finney, B. Wiest, J. The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia |
author_facet |
Davies, M. H. Mix, A. C. Stoner, J. S. Addison, J. A. Jaeger, J. Finney, B. Wiest, J. |
author_sort |
Davies, M. H. |
title |
The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia |
title_short |
The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia |
title_full |
The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia |
title_fullStr |
The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia |
title_full_unstemmed |
The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia |
title_sort |
deglacial transition on the southeastern alaska margin: meltwater input, sea level rise, marine productivity, and sedimentary anoxia |
publisher |
American Geophysical Union |
url |
https://ir.library.oregonstate.edu/concern/articles/gb19f742q |
geographic |
Antarctic The Antarctic Greenland Pacific |
geographic_facet |
Antarctic The Antarctic Greenland Pacific |
genre |
Antarc* Antarctic glaciers Greenland Sea ice Alaska |
genre_facet |
Antarc* Antarctic glaciers Greenland Sea ice Alaska |
op_relation |
https://ir.library.oregonstate.edu/concern/articles/gb19f742q |
op_rights |
In Copyright |
_version_ |
1796311599255912448 |