Holocene Sea-Surface Temperatures in the McMurdo Sound Region, Antarctica, Reconstructed from Isotope Records of Adamussium colbecki
The marine-based West Antarctic Ice Sheet (WAIS) has been hypothesized to be inherently unstable (Mercer, 1978), and if it were to melt, would contribute between 3 to 5 m of global eustatic sea-level rise (Bamber et al., 2009). With the recent collapse of the Larsen B ice shelf attributed to continu...
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ftmaineuniv:oai:digitalcommons.library.umaine.edu:etd-3190 2023-05-15T13:47:33+02:00 Holocene Sea-Surface Temperatures in the McMurdo Sound Region, Antarctica, Reconstructed from Isotope Records of Adamussium colbecki Braddock, Scott 2014-08-01T07:00:00Z application/pdf https://digitalcommons.library.umaine.edu/etd/2153 https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=3190&context=etd unknown DigitalCommons@UMaine https://digitalcommons.library.umaine.edu/etd/2153 https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=3190&context=etd Electronic Theses and Dissertations Ocean temperature Ice shelves Bivalves Fossil Environmental aspects Antarctica McMurdo Sound McMurdo Ice Shelf West Antarctic Ice Sheet Ross Ice Shelf Climate Earth Sciences Oceanography and Atmospheric Sciences and Meteorology text 2014 ftmaineuniv 2023-03-12T19:10:03Z The marine-based West Antarctic Ice Sheet (WAIS) has been hypothesized to be inherently unstable (Mercer, 1978), and if it were to melt, would contribute between 3 to 5 m of global eustatic sea-level rise (Bamber et al., 2009). With the recent collapse of the Larsen B ice shelf attributed to continuous Holocene thinning, amplified by recent warming (Domack et al., 2005), the future stability of other ice shelves remains a critical question. In particular, predicting the future stability of the Ross Ice Shelf (RIS) is essential because of its role in buttressing ice from the WAIS. One way to assess the sensitivity of the RIS, and hence the WAIS, to rising temperatures is to determine ice- shelf behavior during past periods of warmer-than-present temperatures. The aim of this project was to develop a record of Holocene seawater temperatures for the McMurdo Sound region of Antarctica and to use these data to address questions of Holocene climate change and RIS sensitivity to ocean temperature change. I reconstructed paleotemperatures from 6500 years ago to present from the oxygen-isotope ratios of sub-fossil Adamussium colbecki (A. colbecki), marine bivalve mollusks. The equation of Kim and O’Neil (1997) afforded the best approximation of the δ18O-temperature relationship for adult A. colbecki. In addition, Mg/Ca ratios were measured in order to obtain an independent relative-temperature record to compare with δ18O-reconstructed temperatures. Results show that shells dating to 6500-2000 years before present (yr BP) yield warmer-than-present temperatures (by ~0.8 °C). By 1000 yr BP, seawater temperatures had begun to cool in McMurdo Sound. The coldest temperatures for the past 6500 years are recorded by modem A. colbecki. This pattern of Holocene climate change is consistent with existing data from marine animals, glaciers, and ice shelves along the Victoria Land Coast, that suggest a relatively warm mid-Holocene with cooling in the last millennium. The data from this study bear on the behavior of the RIS and the ... Text Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves McMurdo Ice Shelf McMurdo Sound Ross Ice Shelf Victoria Land The University of Maine: DigitalCommons@UMaine Antarctic Victoria Land West Antarctic Ice Sheet McMurdo Sound Ross Ice Shelf Mercer ENVELOPE(65.647,65.647,-70.227,-70.227) McMurdo Ice Shelf ENVELOPE(166.500,166.500,-78.000,-78.000) |
institution |
Open Polar |
collection |
The University of Maine: DigitalCommons@UMaine |
op_collection_id |
ftmaineuniv |
language |
unknown |
topic |
Ocean temperature Ice shelves Bivalves Fossil Environmental aspects Antarctica McMurdo Sound McMurdo Ice Shelf West Antarctic Ice Sheet Ross Ice Shelf Climate Earth Sciences Oceanography and Atmospheric Sciences and Meteorology |
spellingShingle |
Ocean temperature Ice shelves Bivalves Fossil Environmental aspects Antarctica McMurdo Sound McMurdo Ice Shelf West Antarctic Ice Sheet Ross Ice Shelf Climate Earth Sciences Oceanography and Atmospheric Sciences and Meteorology Braddock, Scott Holocene Sea-Surface Temperatures in the McMurdo Sound Region, Antarctica, Reconstructed from Isotope Records of Adamussium colbecki |
topic_facet |
Ocean temperature Ice shelves Bivalves Fossil Environmental aspects Antarctica McMurdo Sound McMurdo Ice Shelf West Antarctic Ice Sheet Ross Ice Shelf Climate Earth Sciences Oceanography and Atmospheric Sciences and Meteorology |
description |
The marine-based West Antarctic Ice Sheet (WAIS) has been hypothesized to be inherently unstable (Mercer, 1978), and if it were to melt, would contribute between 3 to 5 m of global eustatic sea-level rise (Bamber et al., 2009). With the recent collapse of the Larsen B ice shelf attributed to continuous Holocene thinning, amplified by recent warming (Domack et al., 2005), the future stability of other ice shelves remains a critical question. In particular, predicting the future stability of the Ross Ice Shelf (RIS) is essential because of its role in buttressing ice from the WAIS. One way to assess the sensitivity of the RIS, and hence the WAIS, to rising temperatures is to determine ice- shelf behavior during past periods of warmer-than-present temperatures. The aim of this project was to develop a record of Holocene seawater temperatures for the McMurdo Sound region of Antarctica and to use these data to address questions of Holocene climate change and RIS sensitivity to ocean temperature change. I reconstructed paleotemperatures from 6500 years ago to present from the oxygen-isotope ratios of sub-fossil Adamussium colbecki (A. colbecki), marine bivalve mollusks. The equation of Kim and O’Neil (1997) afforded the best approximation of the δ18O-temperature relationship for adult A. colbecki. In addition, Mg/Ca ratios were measured in order to obtain an independent relative-temperature record to compare with δ18O-reconstructed temperatures. Results show that shells dating to 6500-2000 years before present (yr BP) yield warmer-than-present temperatures (by ~0.8 °C). By 1000 yr BP, seawater temperatures had begun to cool in McMurdo Sound. The coldest temperatures for the past 6500 years are recorded by modem A. colbecki. This pattern of Holocene climate change is consistent with existing data from marine animals, glaciers, and ice shelves along the Victoria Land Coast, that suggest a relatively warm mid-Holocene with cooling in the last millennium. The data from this study bear on the behavior of the RIS and the ... |
format |
Text |
author |
Braddock, Scott |
author_facet |
Braddock, Scott |
author_sort |
Braddock, Scott |
title |
Holocene Sea-Surface Temperatures in the McMurdo Sound Region, Antarctica, Reconstructed from Isotope Records of Adamussium colbecki |
title_short |
Holocene Sea-Surface Temperatures in the McMurdo Sound Region, Antarctica, Reconstructed from Isotope Records of Adamussium colbecki |
title_full |
Holocene Sea-Surface Temperatures in the McMurdo Sound Region, Antarctica, Reconstructed from Isotope Records of Adamussium colbecki |
title_fullStr |
Holocene Sea-Surface Temperatures in the McMurdo Sound Region, Antarctica, Reconstructed from Isotope Records of Adamussium colbecki |
title_full_unstemmed |
Holocene Sea-Surface Temperatures in the McMurdo Sound Region, Antarctica, Reconstructed from Isotope Records of Adamussium colbecki |
title_sort |
holocene sea-surface temperatures in the mcmurdo sound region, antarctica, reconstructed from isotope records of adamussium colbecki |
publisher |
DigitalCommons@UMaine |
publishDate |
2014 |
url |
https://digitalcommons.library.umaine.edu/etd/2153 https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=3190&context=etd |
long_lat |
ENVELOPE(65.647,65.647,-70.227,-70.227) ENVELOPE(166.500,166.500,-78.000,-78.000) |
geographic |
Antarctic Victoria Land West Antarctic Ice Sheet McMurdo Sound Ross Ice Shelf Mercer McMurdo Ice Shelf |
geographic_facet |
Antarctic Victoria Land West Antarctic Ice Sheet McMurdo Sound Ross Ice Shelf Mercer McMurdo Ice Shelf |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves McMurdo Ice Shelf McMurdo Sound Ross Ice Shelf Victoria Land |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves McMurdo Ice Shelf McMurdo Sound Ross Ice Shelf Victoria Land |
op_source |
Electronic Theses and Dissertations |
op_relation |
https://digitalcommons.library.umaine.edu/etd/2153 https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=3190&context=etd |
_version_ |
1766247288032722944 |