A Glacial-Geologic Approach to Studying Late Quaternary Climate and Ice Fluctuation in the Southern Hemisphere
This thesis described the distribution of glacial deposits at two sites in the Southern Hemisphere: Nevado Coropuna, in the Peruvian Andes, and Scott Glacier, Antarctica. At each site, glacial-geologic mapping forms the basis for reconstructing former ice extent and for resolving the chronology of g...
Main Author: | |
---|---|
Format: | Text |
Language: | unknown |
Published: |
DigitalCommons@UMaine
2010
|
Subjects: | |
Online Access: | https://digitalcommons.library.umaine.edu/etd/742 https://digitalcommons.library.umaine.edu/context/etd/article/1743/viewcontent/BromleyG2010.pdf |
id |
ftmaineuniv:oai:digitalcommons.library.umaine.edu:etd-1743 |
---|---|
record_format |
openpolar |
spelling |
ftmaineuniv:oai:digitalcommons.library.umaine.edu:etd-1743 2023-06-11T04:05:25+02:00 A Glacial-Geologic Approach to Studying Late Quaternary Climate and Ice Fluctuation in the Southern Hemisphere Bromley, Gordon 2010-01-01T08:00:00Z application/pdf https://digitalcommons.library.umaine.edu/etd/742 https://digitalcommons.library.umaine.edu/context/etd/article/1743/viewcontent/BromleyG2010.pdf unknown DigitalCommons@UMaine https://digitalcommons.library.umaine.edu/etd/742 https://digitalcommons.library.umaine.edu/context/etd/article/1743/viewcontent/BromleyG2010.pdf Electronic Theses and Dissertations Climatic changes Glacial landforms Climate Earth Sciences Glaciology text 2010 ftmaineuniv 2023-05-04T18:00:37Z This thesis described the distribution of glacial deposits at two sites in the Southern Hemisphere: Nevado Coropuna, in the Peruvian Andes, and Scott Glacier, Antarctica. At each site, glacial-geologic mapping forms the basis for reconstructing former ice extent and for resolving the chronology of glaciation with cosmogenic nuclide surface-exposure dating. Together, these data provide answers to fundamental questions about the timing and magnitude of key climate events, such as the Last Glacial Maximum (LGM), in the Southern Hemisphere. On Coropuna (15°S), deposits attest to several glacial episodes during which ice was more extensive than today. Snowline reconstructions and 3He surface-exposure dating show that glaciers last reached their maxima during the LGM in response to an ELA lowering of approximately 750 m. Subsequent deglaciation was interrupted by a major advance between 12 and 14 ka, during which glaciers maintained terminal positions midway between the LGM and modern glacier margins. In contrast to several recently published datasets, my Coropuna record reveals a broad synchrony in the structure of late-Pleistocene climate variability between at least parts of the tropics and higher latitudes. In the southern Transantarctic Mountains, the distribution of glacial deposits at Scott Glacier indicates that the most recent advance was synchronous with the LGM. A longitudinal- surface profile of the glacier based on these LGM deposits indicates that the West Antarctic Ice Sheet (WAIS), at the mouth of Scott Glacier, maintained a surface elevation of ~1100 m. In conjunction with the Ross Sea geologic record and grounding-line chronology, my reconstruction of the former WAIS casts doubt on Antarctica's contribution to Meltwater Pulse 1A at 14.6 ka. Text Antarc* Antarctic Antarctica Ice Sheet Ross Sea Scott Glacier The University of Maine: DigitalCommons@UMaine Antarctic Ela ENVELOPE(9.642,9.642,63.170,63.170) Ross Sea Transantarctic Mountains West Antarctic Ice Sheet |
institution |
Open Polar |
collection |
The University of Maine: DigitalCommons@UMaine |
op_collection_id |
ftmaineuniv |
language |
unknown |
topic |
Climatic changes Glacial landforms Climate Earth Sciences Glaciology |
spellingShingle |
Climatic changes Glacial landforms Climate Earth Sciences Glaciology Bromley, Gordon A Glacial-Geologic Approach to Studying Late Quaternary Climate and Ice Fluctuation in the Southern Hemisphere |
topic_facet |
Climatic changes Glacial landforms Climate Earth Sciences Glaciology |
description |
This thesis described the distribution of glacial deposits at two sites in the Southern Hemisphere: Nevado Coropuna, in the Peruvian Andes, and Scott Glacier, Antarctica. At each site, glacial-geologic mapping forms the basis for reconstructing former ice extent and for resolving the chronology of glaciation with cosmogenic nuclide surface-exposure dating. Together, these data provide answers to fundamental questions about the timing and magnitude of key climate events, such as the Last Glacial Maximum (LGM), in the Southern Hemisphere. On Coropuna (15°S), deposits attest to several glacial episodes during which ice was more extensive than today. Snowline reconstructions and 3He surface-exposure dating show that glaciers last reached their maxima during the LGM in response to an ELA lowering of approximately 750 m. Subsequent deglaciation was interrupted by a major advance between 12 and 14 ka, during which glaciers maintained terminal positions midway between the LGM and modern glacier margins. In contrast to several recently published datasets, my Coropuna record reveals a broad synchrony in the structure of late-Pleistocene climate variability between at least parts of the tropics and higher latitudes. In the southern Transantarctic Mountains, the distribution of glacial deposits at Scott Glacier indicates that the most recent advance was synchronous with the LGM. A longitudinal- surface profile of the glacier based on these LGM deposits indicates that the West Antarctic Ice Sheet (WAIS), at the mouth of Scott Glacier, maintained a surface elevation of ~1100 m. In conjunction with the Ross Sea geologic record and grounding-line chronology, my reconstruction of the former WAIS casts doubt on Antarctica's contribution to Meltwater Pulse 1A at 14.6 ka. |
format |
Text |
author |
Bromley, Gordon |
author_facet |
Bromley, Gordon |
author_sort |
Bromley, Gordon |
title |
A Glacial-Geologic Approach to Studying Late Quaternary Climate and Ice Fluctuation in the Southern Hemisphere |
title_short |
A Glacial-Geologic Approach to Studying Late Quaternary Climate and Ice Fluctuation in the Southern Hemisphere |
title_full |
A Glacial-Geologic Approach to Studying Late Quaternary Climate and Ice Fluctuation in the Southern Hemisphere |
title_fullStr |
A Glacial-Geologic Approach to Studying Late Quaternary Climate and Ice Fluctuation in the Southern Hemisphere |
title_full_unstemmed |
A Glacial-Geologic Approach to Studying Late Quaternary Climate and Ice Fluctuation in the Southern Hemisphere |
title_sort |
glacial-geologic approach to studying late quaternary climate and ice fluctuation in the southern hemisphere |
publisher |
DigitalCommons@UMaine |
publishDate |
2010 |
url |
https://digitalcommons.library.umaine.edu/etd/742 https://digitalcommons.library.umaine.edu/context/etd/article/1743/viewcontent/BromleyG2010.pdf |
long_lat |
ENVELOPE(9.642,9.642,63.170,63.170) |
geographic |
Antarctic Ela Ross Sea Transantarctic Mountains West Antarctic Ice Sheet |
geographic_facet |
Antarctic Ela Ross Sea Transantarctic Mountains West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ross Sea Scott Glacier |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ross Sea Scott Glacier |
op_source |
Electronic Theses and Dissertations |
op_relation |
https://digitalcommons.library.umaine.edu/etd/742 https://digitalcommons.library.umaine.edu/context/etd/article/1743/viewcontent/BromleyG2010.pdf |
_version_ |
1768375319570415616 |