High resolution hydrographic reconstructions from the Southeast Pacific spanning Antarctic Warming event A2 (44-48 Kyr BP)
Knowledge about and reconstructions of past climate change is important to distinguish between natural climate variability on various time scales and the more recent man-made climate changes. In this thesis, sub-millennial resolved proxy records of upper ocean variability (foraminiferal assemblages...
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The University of Bergen
2023
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ftunivbergen:oai:bora.uib.no:11250/3045505 2023-05-15T13:37:05+02:00 High resolution hydrographic reconstructions from the Southeast Pacific spanning Antarctic Warming event A2 (44-48 Kyr BP) Grimen, Torbjørn 2023-01-23T09:30:00Z application/pdf https://hdl.handle.net/11250/3045505 eng eng The University of Bergen https://hdl.handle.net/11250/3045505 Copyright the Author. All rights reserved 756199 Master thesis 2023 ftunivbergen 2023-03-14T17:43:01Z Knowledge about and reconstructions of past climate change is important to distinguish between natural climate variability on various time scales and the more recent man-made climate changes. In this thesis, sub-millennial resolved proxy records of upper ocean variability (foraminiferal assemblages and lithic counts) as well as intermediate ocean variability (benthic oxygen isotopes) are produced from Ocean Drilling Program Site 1233 (41°0.005’S, 74°26.992’W, 838 m.b.s.l) from the Southeast Pacific from 44 to 48 Kyr BP. This interval spans Antarctic Warming event 2, which is one of the most prominent millennial scale warming events observed in Antarctic ice cores. The new records offer the opportunity to simultaneously monitor both AAIW and southeast Pacific surface water properties and unravel how they are influenced by the major atmosphere- and ocean-systems intersecting the study area, as well as unraveling past variations in the Patagonian Ice Sheet. Using planktonic foraminiferal assemblage counts and d 18O to portray climate over A2, we demonstrate that extratropical near surface ocean properties are extremely variable on millennialdecadal timescales. Furthermore, using ice-rafted debris (IRD) counts, and planktonic foraminifer assemblages to infer iceberg supply and melt water input, this study find strong indications for a coupling of the SE Pacific temperature and Patagonian Ice Sheet (PIS) fluctuations during A2 on submillennial time scales. Benthic foraminifera d 18O and d 13C are used to monitor the properties of AAIW close to its source in the Southeast Pacific, and the new benthic isotopic results spanning A2 show that variations in intermediate ocean properties and climate (foraminiferal census counts and planktic isotopes) of the Southeast Pacific closely align with the record of air temperatures from the EPICA Dronning Maud Land ice core on millennial and centennial scales. The abrupt and concurrent shifts in extratropical surface and intermediate ocean properties over A2 are ... Master Thesis Antarc* Antarctic Dronning Maud Land EPICA ice core Ice Sheet Iceberg* University of Bergen: Bergen Open Research Archive (BORA-UiB) Antarctic Dronning Maud Land Pacific |
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Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
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ftunivbergen |
language |
English |
topic |
756199 |
spellingShingle |
756199 Grimen, Torbjørn High resolution hydrographic reconstructions from the Southeast Pacific spanning Antarctic Warming event A2 (44-48 Kyr BP) |
topic_facet |
756199 |
description |
Knowledge about and reconstructions of past climate change is important to distinguish between natural climate variability on various time scales and the more recent man-made climate changes. In this thesis, sub-millennial resolved proxy records of upper ocean variability (foraminiferal assemblages and lithic counts) as well as intermediate ocean variability (benthic oxygen isotopes) are produced from Ocean Drilling Program Site 1233 (41°0.005’S, 74°26.992’W, 838 m.b.s.l) from the Southeast Pacific from 44 to 48 Kyr BP. This interval spans Antarctic Warming event 2, which is one of the most prominent millennial scale warming events observed in Antarctic ice cores. The new records offer the opportunity to simultaneously monitor both AAIW and southeast Pacific surface water properties and unravel how they are influenced by the major atmosphere- and ocean-systems intersecting the study area, as well as unraveling past variations in the Patagonian Ice Sheet. Using planktonic foraminiferal assemblage counts and d 18O to portray climate over A2, we demonstrate that extratropical near surface ocean properties are extremely variable on millennialdecadal timescales. Furthermore, using ice-rafted debris (IRD) counts, and planktonic foraminifer assemblages to infer iceberg supply and melt water input, this study find strong indications for a coupling of the SE Pacific temperature and Patagonian Ice Sheet (PIS) fluctuations during A2 on submillennial time scales. Benthic foraminifera d 18O and d 13C are used to monitor the properties of AAIW close to its source in the Southeast Pacific, and the new benthic isotopic results spanning A2 show that variations in intermediate ocean properties and climate (foraminiferal census counts and planktic isotopes) of the Southeast Pacific closely align with the record of air temperatures from the EPICA Dronning Maud Land ice core on millennial and centennial scales. The abrupt and concurrent shifts in extratropical surface and intermediate ocean properties over A2 are ... |
format |
Master Thesis |
author |
Grimen, Torbjørn |
author_facet |
Grimen, Torbjørn |
author_sort |
Grimen, Torbjørn |
title |
High resolution hydrographic reconstructions from the Southeast Pacific spanning Antarctic Warming event A2 (44-48 Kyr BP) |
title_short |
High resolution hydrographic reconstructions from the Southeast Pacific spanning Antarctic Warming event A2 (44-48 Kyr BP) |
title_full |
High resolution hydrographic reconstructions from the Southeast Pacific spanning Antarctic Warming event A2 (44-48 Kyr BP) |
title_fullStr |
High resolution hydrographic reconstructions from the Southeast Pacific spanning Antarctic Warming event A2 (44-48 Kyr BP) |
title_full_unstemmed |
High resolution hydrographic reconstructions from the Southeast Pacific spanning Antarctic Warming event A2 (44-48 Kyr BP) |
title_sort |
high resolution hydrographic reconstructions from the southeast pacific spanning antarctic warming event a2 (44-48 kyr bp) |
publisher |
The University of Bergen |
publishDate |
2023 |
url |
https://hdl.handle.net/11250/3045505 |
geographic |
Antarctic Dronning Maud Land Pacific |
geographic_facet |
Antarctic Dronning Maud Land Pacific |
genre |
Antarc* Antarctic Dronning Maud Land EPICA ice core Ice Sheet Iceberg* |
genre_facet |
Antarc* Antarctic Dronning Maud Land EPICA ice core Ice Sheet Iceberg* |
op_relation |
https://hdl.handle.net/11250/3045505 |
op_rights |
Copyright the Author. All rights reserved |
_version_ |
1766087918743453696 |