University of Tasmania
Browse

File(s) under permanent embargo

Modern to glacial age subglacial meltwater drainage at Law Dome, coastal East Antarctica from topography, sediments and jökulhlaup observations

journal contribution
posted on 2023-05-19, 07:46 authored by Goodwin, ID, Jason RobertsJason Roberts, Etheridge, DM, Hellstrom, J, Andrew MoyAndrew Moy, Ribo, M, Smith, AM
Rare jökulhlaup events, also known as subglacial lake outburst flood events, have been observed at the Law Dome ice margin and provide an insight into the physical characteristics of subglacial meltwater and drainage. The subglacial topography based on data from the BEDMAP2 and ICECAP projects, together with subsurface transects of the ice margin obtained using groundpenetrating radar, reveal several lakes and lake-like depressions and the drainage pathways of two jökulhlaup events. Oxygen isotope typing of the meltwater during the most recent (2014) jökulhlaup event, combined with ice margin stratigraphy, enable the identification of ice tunnel melt pathways that exploit the 30–90° dipping basal ice layering. The presence of subglacial meltwater beneath Law Dome during the Holocene to Glacial periods is confirmed by the dendritic drainage pattern in the subglacial morphology and extensive layers of basal regelation ice and subglacial carbonate precipitate deposits found within the Løken Moraines sediments. These subglacial carbonates, including ooid layers, formed from the mixing of glacial meltwater and seawater at 72 ka BP. The combined evidence indicates that the ocean discharge of subglacial meltwater may be variable and/or is periodically blocked by basal freezing events near the ice sheet terminus.

History

Publication title

Geological Society Special Publication

Volume

461

Article number

SP461.16

Number

SP461.16

Pagination

1-16

ISSN

0305-8719

Department/School

Institute for Marine and Antarctic Studies

Publisher

Geological Society Publishing House

Place of publication

United Kingdom

Rights statement

Copyright 2017 The Author(s)

Repository Status

  • Restricted

Socio-economic Objectives

Understanding climate change not elsewhere classified

Usage metrics

    University Of Tasmania

    Categories

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC