Timing of Svalbard/Barents Sea Ice Sheet Decay during the Last Glacial Termination
The Arctic and North Atlantic underwent significant climactic changes since the Last Glacial Maximum (25,000 years before present (1950 AD); ka BP), but offsets in the timing of events between the two regions are poorly constrained due to age model uncertainties that arise from changing radiocarbon...
Main Author: | |
---|---|
Format: | Thesis |
Language: | unknown |
Published: |
Digital Commons @ University of South Florida
2014
|
Subjects: | |
Online Access: | https://digitalcommons.usf.edu/etd/5313 https://digitalcommons.usf.edu/context/etd/article/6509/viewcontent/Snow_usf_0206M_12491.pdf |
id |
ftunisfloridatam:oai:digitalcommons.usf.edu:etd-6509 |
---|---|
record_format |
openpolar |
spelling |
ftunisfloridatam:oai:digitalcommons.usf.edu:etd-6509 2023-06-11T04:09:22+02:00 Timing of Svalbard/Barents Sea Ice Sheet Decay during the Last Glacial Termination Snow, Tasha 2014-07-09T07:00:00Z application/pdf https://digitalcommons.usf.edu/etd/5313 https://digitalcommons.usf.edu/context/etd/article/6509/viewcontent/Snow_usf_0206M_12491.pdf unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/etd/5313 https://digitalcommons.usf.edu/context/etd/article/6509/viewcontent/Snow_usf_0206M_12491.pdf default USF Tampa Graduate Theses and Dissertations foraminifera Fram Strait isotopes meltwater paleoceanography radiocarbon reservoir age Climate Geology thesis 2014 ftunisfloridatam 2023-05-04T18:04:45Z The Arctic and North Atlantic underwent significant climactic changes since the Last Glacial Maximum (25,000 years before present (1950 AD); ka BP), but offsets in the timing of events between the two regions are poorly constrained due to age model uncertainties that arise from changing radiocarbon reservoir ages. Here, we use a relatively high-resolution, multi-proxy stable isotope and sedimentologic dataset from Eastern Fram Strait (ODP Leg 162 Site 986) marine sediments to constrain the timing of Svalbard/Barents Sea Ice Sheet decay and infer deglacial reservoir ages over the last 30 ka. We use magnetic susceptibility, inorganic and organic carbon, foraminiferal assemblage counts, planktonic foraminiferal isotopes, and iceberg-rafted debris proxies to infer glaciomarine and paleoclimactic processes in Eastern Fram Strait. Significant negative Neogloboquadrina pachyderma (sinistral) δ18O episodes from background levels at 18.8 ka (-3.0 /) and 20.4 ka (-0.8 /) (on a radiocarbon-based age model) are shown to indicate meltwater discharge events from the Svalbard/Barents Sea Ice Sheet during the early glacial termination (21-14.7 ka). To allow for direct comparison between the timing of Eastern Fram Strait meltwater events and North Atlantic climate changes, the ODP Site 986 age model is correlated to the well-dated Greenland Ice Sheet Project 2 (GISP2) ice core δ18O record. The refined age model suggests that 16.0 and 18.1 ka are more realistic estimates for the meltwater events, inferring surface ocean reservoir age shifts of 1750 ± 1050 years in Eastern Fram Strait during the early glacial termination. Trends in reservoir ages throughout the last deglaciation mirror Nordic Sea deep ocean circulation changes and previously reported trends in the sub-polar North Atlantic; however, reservoir ages appear to be greater in Eastern Fram Strait. We hypothesize that processes affecting the distribution of reservoir ages in the North Atlantic and Arctic (e.g. sea ice cover, meltwater input, and ocean circulation) may ... Thesis Arctic Barents Sea Foraminifera* Fram Strait Greenland Greenland Ice Sheet Project ice core Ice Sheet Iceberg* Magnetic susceptibility Neogloboquadrina pachyderma Nordic Sea North Atlantic Sea ice Svalbard Svalbard-Barents Sea Ice sheet Digital Commons University of South Florida (USF) Arctic Svalbard Barents Sea Greenland |
institution |
Open Polar |
collection |
Digital Commons University of South Florida (USF) |
op_collection_id |
ftunisfloridatam |
language |
unknown |
topic |
foraminifera Fram Strait isotopes meltwater paleoceanography radiocarbon reservoir age Climate Geology |
spellingShingle |
foraminifera Fram Strait isotopes meltwater paleoceanography radiocarbon reservoir age Climate Geology Snow, Tasha Timing of Svalbard/Barents Sea Ice Sheet Decay during the Last Glacial Termination |
topic_facet |
foraminifera Fram Strait isotopes meltwater paleoceanography radiocarbon reservoir age Climate Geology |
description |
The Arctic and North Atlantic underwent significant climactic changes since the Last Glacial Maximum (25,000 years before present (1950 AD); ka BP), but offsets in the timing of events between the two regions are poorly constrained due to age model uncertainties that arise from changing radiocarbon reservoir ages. Here, we use a relatively high-resolution, multi-proxy stable isotope and sedimentologic dataset from Eastern Fram Strait (ODP Leg 162 Site 986) marine sediments to constrain the timing of Svalbard/Barents Sea Ice Sheet decay and infer deglacial reservoir ages over the last 30 ka. We use magnetic susceptibility, inorganic and organic carbon, foraminiferal assemblage counts, planktonic foraminiferal isotopes, and iceberg-rafted debris proxies to infer glaciomarine and paleoclimactic processes in Eastern Fram Strait. Significant negative Neogloboquadrina pachyderma (sinistral) δ18O episodes from background levels at 18.8 ka (-3.0 /) and 20.4 ka (-0.8 /) (on a radiocarbon-based age model) are shown to indicate meltwater discharge events from the Svalbard/Barents Sea Ice Sheet during the early glacial termination (21-14.7 ka). To allow for direct comparison between the timing of Eastern Fram Strait meltwater events and North Atlantic climate changes, the ODP Site 986 age model is correlated to the well-dated Greenland Ice Sheet Project 2 (GISP2) ice core δ18O record. The refined age model suggests that 16.0 and 18.1 ka are more realistic estimates for the meltwater events, inferring surface ocean reservoir age shifts of 1750 ± 1050 years in Eastern Fram Strait during the early glacial termination. Trends in reservoir ages throughout the last deglaciation mirror Nordic Sea deep ocean circulation changes and previously reported trends in the sub-polar North Atlantic; however, reservoir ages appear to be greater in Eastern Fram Strait. We hypothesize that processes affecting the distribution of reservoir ages in the North Atlantic and Arctic (e.g. sea ice cover, meltwater input, and ocean circulation) may ... |
format |
Thesis |
author |
Snow, Tasha |
author_facet |
Snow, Tasha |
author_sort |
Snow, Tasha |
title |
Timing of Svalbard/Barents Sea Ice Sheet Decay during the Last Glacial Termination |
title_short |
Timing of Svalbard/Barents Sea Ice Sheet Decay during the Last Glacial Termination |
title_full |
Timing of Svalbard/Barents Sea Ice Sheet Decay during the Last Glacial Termination |
title_fullStr |
Timing of Svalbard/Barents Sea Ice Sheet Decay during the Last Glacial Termination |
title_full_unstemmed |
Timing of Svalbard/Barents Sea Ice Sheet Decay during the Last Glacial Termination |
title_sort |
timing of svalbard/barents sea ice sheet decay during the last glacial termination |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2014 |
url |
https://digitalcommons.usf.edu/etd/5313 https://digitalcommons.usf.edu/context/etd/article/6509/viewcontent/Snow_usf_0206M_12491.pdf |
geographic |
Arctic Svalbard Barents Sea Greenland |
geographic_facet |
Arctic Svalbard Barents Sea Greenland |
genre |
Arctic Barents Sea Foraminifera* Fram Strait Greenland Greenland Ice Sheet Project ice core Ice Sheet Iceberg* Magnetic susceptibility Neogloboquadrina pachyderma Nordic Sea North Atlantic Sea ice Svalbard Svalbard-Barents Sea Ice sheet |
genre_facet |
Arctic Barents Sea Foraminifera* Fram Strait Greenland Greenland Ice Sheet Project ice core Ice Sheet Iceberg* Magnetic susceptibility Neogloboquadrina pachyderma Nordic Sea North Atlantic Sea ice Svalbard Svalbard-Barents Sea Ice sheet |
op_source |
USF Tampa Graduate Theses and Dissertations |
op_relation |
https://digitalcommons.usf.edu/etd/5313 https://digitalcommons.usf.edu/context/etd/article/6509/viewcontent/Snow_usf_0206M_12491.pdf |
op_rights |
default |
_version_ |
1768383183386050560 |