The recent history of the Antarctic ice sheet : constraints from sea-level change
type: CreativeWork
description: The rheology of the earth and the history of ice sheets, which have a major contributing role in climate change, are both subjects of considerable interest in earth sciences, and the study of sea-level change provides insight into both. Sea-level change since the last glacial maximum (LGM), about 18,000 years ago, can be explained as the sum of three contributions: the sea-level rise due to melting of the Pleistocene ice sheets; the isostatic and gravitational response to the melting of these ice sheets; and the isostatic and gravitational response to the water added to the oceans. Thus, sea-level change varies with location, and is dependent on the volume and distribution of the ice removed, the shape of the oceans, and the rheological structure of the earth. Using sea-level records from appropriate locations, and numerical models of the response of the earth to surface loads, constraints can be placed on some of these parameters. In this thesis, I use new sea-level observations from Antarctica and Queensland to estimate the former distribution of ice at several Antarctic sites, the total amount of extra ice which was stored in Antarctica at the LGM compared to the present, and the eustatic sea-level change which has occurred in the last 6,000 years. I present a new high-resolution sea-level record from the Vestfold Hills, Antarctica, obtained by dating the lacustrine-marine and marine-lacustrine transitions in sediment cores from lakes which were formerly connected to the sea. A sea-level maximum ~9 m above present sea-level 6,000 years ago is documented. Sea-level observations from other Antarctic sites have been compiled and compared with predictions derived from simplified models of melting at the ice sheet margin. The results indicate that at the LGM the East Antarctic ice sheet margin was 25 - 100 km beyond its present position, resulting in ice thicknesses of 500 - 1000 m at sites now on the coast. Eustatic sea-level change in the last 6,000 years can be est…
abstract: The rheology of the earth and the history of ice sheets, which have a major contributing role in climate change, are both subjects of considerable interest in earth sciences, and the study of sea-level change provides insight into both. Sea-level change since the last glacial maximum (LGM), about 18,000 years ago, can be explained as the sum of three contributions: the sea-level rise due to melting of the Pleistocene ice sheets; the isostatic and gravitational response to the melting of these ice sheets; and the isostatic and gravitational response to the water added to the oceans. Thus, sea-level change varies with location, and is dependent on the volume and distribution of the ice removed, the shape of the oceans, and the rheological structure of the earth. Using sea-level records from appropriate locations, and numerical models of the response of the earth to surface loads, constraints can be placed on some of these parameters. In this thesis, I use new sea-level observations from Antarctica and Queensland to estimate the former distribution of ice at several Antarctic sites, the total amount of extra ice which was stored in Antarctica at the LGM compared to the present, and the eustatic sea-level change which has occurred in the last 6,000 years. I present a new high-resolution sea-level record from the Vestfold Hills, Antarctica, obtained by dating the lacustrine-marine and marine-lacustrine transitions in sediment cores from lakes which were formerly connected to the sea. A sea-level maximum ~9 m above present sea-level 6,000 years ago is documented. Sea-level observations from other Antarctic sites have been compiled and compared with predictions derived from simplified models of melting at the ice sheet margin. The results indicate that at the LGM the East Antarctic ice sheet margin was 25 - 100 km beyond its present position, resulting in ice thicknesses of 500 - 1000 m at sites now on the coast. Eustatic sea-level change in the last 6,000 years can be est…
author: Zwartz, Daniel Peter
language: en
date published: 1995
date modified: 2026-07-24T01:07:43Z
provider: Australian Catholic University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Australian Catholic University

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1885/114548