RECONSTRUCTING ICE SHEET SURFACE CHANGES IN WESTERN DRONNING MAUD LAND, ANTARCTICA

Understanding climate-driven changes in global land-based ice volume is a critical component in our capability to predict how global sea level will rise as a consequence of the current human-driven climate change. At the last glacial maximum (LGM, which peaked around 20 ka), ephemeral ice sheets cov...

Full description

Bibliographic Details
Main Author: Jennifer C H Newall (10724127)
Format: Thesis
Language:unknown
Published: 2021
Subjects:
DML
Online Access:https://doi.org/10.25394/pgs.14512074.v1
id ftsmithonian:oai:figshare.com:article/14512074
record_format openpolar
institution Open Polar
collection Unknown
op_collection_id ftsmithonian
language unknown
topic Geology
Physical Geography
Geomorphology and Regolith and Landscape Evolution
Glaciology
Quaternary Environments
Surface Processes
Earth Sciences not elsewhere classified
Glacial geomorphology
ANTARCTICA
East Antarctic Ice Sheet
Nunatak
nunataks
Dronning Maud Land
geomorphological mapping
spellingShingle Geology
Physical Geography
Geomorphology and Regolith and Landscape Evolution
Glaciology
Quaternary Environments
Surface Processes
Earth Sciences not elsewhere classified
Glacial geomorphology
ANTARCTICA
East Antarctic Ice Sheet
Nunatak
nunataks
Dronning Maud Land
geomorphological mapping
Jennifer C H Newall (10724127)
RECONSTRUCTING ICE SHEET SURFACE CHANGES IN WESTERN DRONNING MAUD LAND, ANTARCTICA
topic_facet Geology
Physical Geography
Geomorphology and Regolith and Landscape Evolution
Glaciology
Quaternary Environments
Surface Processes
Earth Sciences not elsewhere classified
Glacial geomorphology
ANTARCTICA
East Antarctic Ice Sheet
Nunatak
nunataks
Dronning Maud Land
geomorphological mapping
description Understanding climate-driven changes in global land-based ice volume is a critical component in our capability to predict how global sea level will rise as a consequence of the current human-driven climate change. At the last glacial maximum (LGM, which peaked around 20 ka), ephemeral ice sheets covered vast regions of the northern hemisphere while both the Greenland and Antarctic ice sheets were more extensive than at present. As global temperatures rose at the transition into the Holocene, driving the LGM deglaciation, eustatic sea level rose by approximately 125 m. The east Antarctic ice sheet (EAIS) is the largest ice sheet on Earth today, holding an ice volume equivalent to ca. 53 m rise in global sea level. Considering current trends in global climate, specifically rapidly increasing atmospheric CO 2 levels and global temperature, it is important to improve our understanding of how the EAIS will respond to global warming so that we can make better predictions of future sea level changes to guide community adaptation and planning efforts. Numerical ice sheet models which inform projections of future ice volume changes, and can, therefore, yield projections of sea level rise, rely on empirical data to test their ability to accurately represent former and present ice configurations. However, there is a general lack of data on the paleoglaciology of the EAIS along the western Dronning Maud Land (DML) margin. In order to address this situation, the paleoglaciology of western DML forms the focus of the work presented in this thesis. Together with collaborators within the MAGIC-DML consortium (Mapping, Measuring and Modelling Antarctic Geomorphology and Ice Change in Dronning Maud Land) that provides the funding for this MS project, the author has performed geomorphological mapping across western DML; an area of approximately 200,000 km 2 . The results of the mapping presented in this thesis will provide the basis for a detailed glacial reconstruction of the region. The geomorphological mapping was completed almost entirely by remote sensing using very high-resolution (sub-meter in the panchromatic) WordView-2 and WorldView-3 (WV) satellite imagery, combined with ground validation studies during field work. Compared to Landsat products, the improved spatial resolution provided by WV imagery has fundamentally changed the scale and detail at which remote sensing based geomorphological mapping can be completed. The mapping presented here is focused on the glacial geomorphology of mountain summits and flanks that protrude through the ice sheet’s surface (nunataks). In our study area of western DML these nunatak surfaces make up <0.2 % of the total surface area, and the landforms mapped here are generally smaller than can be identified from Landsat products (30 m spatial resolution). The detail achieved in our mapping, across such a vast, remote area that presents numerous obstacles to accessibility highlights the benefits of utilizing the new VHR WV data. As such an evaluation of the WV data, as applied to geomorphological mapping is presented here together with our mapping of the glacial geomorphology of western DML. The results of which provides evidence of ice having overridden sites at all elevations across the entire study area; from the highest elevation inland nunataks that form the coast-parallel escarpment, to low-elevation emerging nunataks close to the coast. Hence from our studies of the glacial geomorphology of this region we can ascertain that, at some point in the glacial history of western DML, ice covered all of the mountain summits that are exposed today, indicating an ice sheet surface lowering of up to 700 m in some places.
format Thesis
author Jennifer C H Newall (10724127)
author_facet Jennifer C H Newall (10724127)
author_sort Jennifer C H Newall (10724127)
title RECONSTRUCTING ICE SHEET SURFACE CHANGES IN WESTERN DRONNING MAUD LAND, ANTARCTICA
title_short RECONSTRUCTING ICE SHEET SURFACE CHANGES IN WESTERN DRONNING MAUD LAND, ANTARCTICA
title_full RECONSTRUCTING ICE SHEET SURFACE CHANGES IN WESTERN DRONNING MAUD LAND, ANTARCTICA
title_fullStr RECONSTRUCTING ICE SHEET SURFACE CHANGES IN WESTERN DRONNING MAUD LAND, ANTARCTICA
title_full_unstemmed RECONSTRUCTING ICE SHEET SURFACE CHANGES IN WESTERN DRONNING MAUD LAND, ANTARCTICA
title_sort reconstructing ice sheet surface changes in western dronning maud land, antarctica
publishDate 2021
url https://doi.org/10.25394/pgs.14512074.v1
geographic Antarctic
Dronning Maud Land
East Antarctic Ice Sheet
Greenland
geographic_facet Antarctic
Dronning Maud Land
East Antarctic Ice Sheet
Greenland
genre Antarc*
Antarctic
Antarctica
DML
Dronning Maud Land
Greenland
Ice Sheet
genre_facet Antarc*
Antarctic
Antarctica
DML
Dronning Maud Land
Greenland
Ice Sheet
op_relation https://figshare.com/articles/thesis/RECONSTRUCTING_ICE_SHEET_SURFACE_CHANGES_IN_WESTERN_DRONNING_MAUD_LAND_ANTARCTICA/14512074
doi:10.25394/pgs.14512074.v1
op_rights CC BY 4.0
op_rightsnorm CC-BY
op_doi https://doi.org/10.25394/pgs.14512074.v1
_version_ 1766264657236983808
spelling ftsmithonian:oai:figshare.com:article/14512074 2023-05-15T13:57:04+02:00 RECONSTRUCTING ICE SHEET SURFACE CHANGES IN WESTERN DRONNING MAUD LAND, ANTARCTICA Jennifer C H Newall (10724127) 2021-04-29T17:51:19Z https://doi.org/10.25394/pgs.14512074.v1 unknown https://figshare.com/articles/thesis/RECONSTRUCTING_ICE_SHEET_SURFACE_CHANGES_IN_WESTERN_DRONNING_MAUD_LAND_ANTARCTICA/14512074 doi:10.25394/pgs.14512074.v1 CC BY 4.0 CC-BY Geology Physical Geography Geomorphology and Regolith and Landscape Evolution Glaciology Quaternary Environments Surface Processes Earth Sciences not elsewhere classified Glacial geomorphology ANTARCTICA East Antarctic Ice Sheet Nunatak nunataks Dronning Maud Land geomorphological mapping Text Thesis 2021 ftsmithonian https://doi.org/10.25394/pgs.14512074.v1 2021-05-05T17:05:44Z Understanding climate-driven changes in global land-based ice volume is a critical component in our capability to predict how global sea level will rise as a consequence of the current human-driven climate change. At the last glacial maximum (LGM, which peaked around 20 ka), ephemeral ice sheets covered vast regions of the northern hemisphere while both the Greenland and Antarctic ice sheets were more extensive than at present. As global temperatures rose at the transition into the Holocene, driving the LGM deglaciation, eustatic sea level rose by approximately 125 m. The east Antarctic ice sheet (EAIS) is the largest ice sheet on Earth today, holding an ice volume equivalent to ca. 53 m rise in global sea level. Considering current trends in global climate, specifically rapidly increasing atmospheric CO 2 levels and global temperature, it is important to improve our understanding of how the EAIS will respond to global warming so that we can make better predictions of future sea level changes to guide community adaptation and planning efforts. Numerical ice sheet models which inform projections of future ice volume changes, and can, therefore, yield projections of sea level rise, rely on empirical data to test their ability to accurately represent former and present ice configurations. However, there is a general lack of data on the paleoglaciology of the EAIS along the western Dronning Maud Land (DML) margin. In order to address this situation, the paleoglaciology of western DML forms the focus of the work presented in this thesis. Together with collaborators within the MAGIC-DML consortium (Mapping, Measuring and Modelling Antarctic Geomorphology and Ice Change in Dronning Maud Land) that provides the funding for this MS project, the author has performed geomorphological mapping across western DML; an area of approximately 200,000 km 2 . The results of the mapping presented in this thesis will provide the basis for a detailed glacial reconstruction of the region. The geomorphological mapping was completed almost entirely by remote sensing using very high-resolution (sub-meter in the panchromatic) WordView-2 and WorldView-3 (WV) satellite imagery, combined with ground validation studies during field work. Compared to Landsat products, the improved spatial resolution provided by WV imagery has fundamentally changed the scale and detail at which remote sensing based geomorphological mapping can be completed. The mapping presented here is focused on the glacial geomorphology of mountain summits and flanks that protrude through the ice sheet’s surface (nunataks). In our study area of western DML these nunatak surfaces make up <0.2 % of the total surface area, and the landforms mapped here are generally smaller than can be identified from Landsat products (30 m spatial resolution). The detail achieved in our mapping, across such a vast, remote area that presents numerous obstacles to accessibility highlights the benefits of utilizing the new VHR WV data. As such an evaluation of the WV data, as applied to geomorphological mapping is presented here together with our mapping of the glacial geomorphology of western DML. The results of which provides evidence of ice having overridden sites at all elevations across the entire study area; from the highest elevation inland nunataks that form the coast-parallel escarpment, to low-elevation emerging nunataks close to the coast. Hence from our studies of the glacial geomorphology of this region we can ascertain that, at some point in the glacial history of western DML, ice covered all of the mountain summits that are exposed today, indicating an ice sheet surface lowering of up to 700 m in some places. Thesis Antarc* Antarctic Antarctica DML Dronning Maud Land Greenland Ice Sheet Unknown Antarctic Dronning Maud Land East Antarctic Ice Sheet Greenland