Millennial-scale climate events in an Italian speleothem: a pilot study covering the last glacial period
Millennial-scale climate events are the best example of naturally occurring rapid climate change. However, the absolute timing and underlying cause of these events remains unknown, largely due to the absence of long continuous records of the events that are anchored in radiometric time. Speleothems...
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ftumelbourne:oai:jupiter.its.unimelb.edu.au:11343/229460 2024-06-02T08:07:30+00:00 Millennial-scale climate events in an Italian speleothem: a pilot study covering the last glacial period Corrick, Ellen 2014 http://hdl.handle.net/11343/229460 unknown http://hdl.handle.net/11343/229460 Terms and Conditions: Copyright in works deposited in Minerva Access is retained by the copyright owner. You may download, print or save electronic copies of a whole work, or part of a work, for your own research or study or as permitted under the Copyright Act 1968. You must obtain permission from the copyright owner to use the work for any other purpose. If you believe this copyrighted work is available on the University of Melbourne network in such a way that constitutes copyright infringement, or a breach of an agreed licence or contract, please notify the Copyright Office at copyright-office@unimelb.edu.au Honours thesis 2014 ftumelbourne 2024-05-06T12:02:00Z Millennial-scale climate events are the best example of naturally occurring rapid climate change. However, the absolute timing and underlying cause of these events remains unknown, largely due to the absence of long continuous records of the events that are anchored in radiometric time. Speleothems (cave deposits such as stalagmites) can preserve long, continuous and precisely dated records of millennial-scale climate events, thus providing vital information on their timing and underlying cause. A subaqueous speleothem from Corchia Cave, NW Italy, contains a palaeoclimate record spanning the last 1 million years, presenting an unprecedented opportunity to investigate the long-term pattern of millennial-scale climate events. The pilot study presented here tests the potential of this speleothem to record millennial-scale climate events by focusing on the last glacial period (120-12 ka), a period already well captured in Greenland ice cores (the current reference record of the events). Due to its slow growth rate, microanalytical techniques were applied to the speleothem to measure three potential climate proxies: Mg (a proxy for temperature), Zn (a proxy for cold climate intervals) and 5180 (a proxy for rainfall amount). Uranium-thorium (U-Th) dating was undertaken to provide the temporal framework. Mg and Zn provide an impressive record of fluctuations consistent with millennial time scales, whilst the 8180 analysis is limited by the resolution and precision of the technique applied. Unexpectedly, the U-Th results reveal an age offset, whereby the timing of high-amplitude regional climate events is at least 2 kyr too old. This age offset, possibly due to a process known as `thorium scavenging', casts serious doubt over the integrity of the chronology, precluding any robust comparison with the Greenland ice-core record. To partly overcome the age offset issue, a first-order correction was performed by tying the speleothem series to well-constrained Corchia Cave stalagmite records. This correction is only possible ... Other/Unknown Material Greenland Greenland ice core Greenland ice cores ice core The University of Melbourne: Digital Repository Greenland |
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Open Polar |
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The University of Melbourne: Digital Repository |
op_collection_id |
ftumelbourne |
language |
unknown |
description |
Millennial-scale climate events are the best example of naturally occurring rapid climate change. However, the absolute timing and underlying cause of these events remains unknown, largely due to the absence of long continuous records of the events that are anchored in radiometric time. Speleothems (cave deposits such as stalagmites) can preserve long, continuous and precisely dated records of millennial-scale climate events, thus providing vital information on their timing and underlying cause. A subaqueous speleothem from Corchia Cave, NW Italy, contains a palaeoclimate record spanning the last 1 million years, presenting an unprecedented opportunity to investigate the long-term pattern of millennial-scale climate events. The pilot study presented here tests the potential of this speleothem to record millennial-scale climate events by focusing on the last glacial period (120-12 ka), a period already well captured in Greenland ice cores (the current reference record of the events). Due to its slow growth rate, microanalytical techniques were applied to the speleothem to measure three potential climate proxies: Mg (a proxy for temperature), Zn (a proxy for cold climate intervals) and 5180 (a proxy for rainfall amount). Uranium-thorium (U-Th) dating was undertaken to provide the temporal framework. Mg and Zn provide an impressive record of fluctuations consistent with millennial time scales, whilst the 8180 analysis is limited by the resolution and precision of the technique applied. Unexpectedly, the U-Th results reveal an age offset, whereby the timing of high-amplitude regional climate events is at least 2 kyr too old. This age offset, possibly due to a process known as `thorium scavenging', casts serious doubt over the integrity of the chronology, precluding any robust comparison with the Greenland ice-core record. To partly overcome the age offset issue, a first-order correction was performed by tying the speleothem series to well-constrained Corchia Cave stalagmite records. This correction is only possible ... |
format |
Other/Unknown Material |
author |
Corrick, Ellen |
spellingShingle |
Corrick, Ellen Millennial-scale climate events in an Italian speleothem: a pilot study covering the last glacial period |
author_facet |
Corrick, Ellen |
author_sort |
Corrick, Ellen |
title |
Millennial-scale climate events in an Italian speleothem: a pilot study covering the last glacial period |
title_short |
Millennial-scale climate events in an Italian speleothem: a pilot study covering the last glacial period |
title_full |
Millennial-scale climate events in an Italian speleothem: a pilot study covering the last glacial period |
title_fullStr |
Millennial-scale climate events in an Italian speleothem: a pilot study covering the last glacial period |
title_full_unstemmed |
Millennial-scale climate events in an Italian speleothem: a pilot study covering the last glacial period |
title_sort |
millennial-scale climate events in an italian speleothem: a pilot study covering the last glacial period |
publishDate |
2014 |
url |
http://hdl.handle.net/11343/229460 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Greenland ice core Greenland ice cores ice core |
genre_facet |
Greenland Greenland ice core Greenland ice cores ice core |
op_relation |
http://hdl.handle.net/11343/229460 |
op_rights |
Terms and Conditions: Copyright in works deposited in Minerva Access is retained by the copyright owner. You may download, print or save electronic copies of a whole work, or part of a work, for your own research or study or as permitted under the Copyright Act 1968. You must obtain permission from the copyright owner to use the work for any other purpose. If you believe this copyrighted work is available on the University of Melbourne network in such a way that constitutes copyright infringement, or a breach of an agreed licence or contract, please notify the Copyright Office at copyright-office@unimelb.edu.au |
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