Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) – New evidence from Rauer Group

Sonja Berg, Duanne WHITE, Ole Bennike, Reka-Hajnalka Fülöp, David Fink, Bernd Wagner, Martin Melles

    Research output: Contribution to journalArticle

    2 Citations (Scopus)

    Abstract

    Limited information on the East Antarctic Ice Sheet (EAIS) geometry during Marine Isotope Stage 3 (MIS 3; 60-25 ka) restricts our understanding of its behaviour during periods of climate and sea level change. Ice sheet models forced by global parameters suggest an expanded EAIS compared to the Holocene during MIS 3, but field evidence from East Antarctic coastal areas contradicts such modelling, and suggests that the ice sheet margins were no more advanced than at present. Here we present a new lake sediment record, and cosmogenic exposure results from bedrock, which confirm that Rauer Group (eastern Prydz Bay) was ice-free for much of MIS 3. We also refine the likely duration of the Last Glacial Maximum (LGM) glaciation in the region. Lacustrine and marine sediments from Rauer Group indicate the penultimate period of ice retreat predates 50 ka. The lacustrine record indicates a change from warmer/wetter conditions to cooler/drier conditions after ca. 35 ka. Substantive ice sheet re-advance, however, may not have occurred until much closer to 20 ka. Contemporary coastal areas were still connected to the sea during MIS 3, restricting the possible extent of grounded ice in Prydz Bay on the continental shelf. In contrast, relative sea levels (RSL) deduced from field evidence indicate an extra ice load averaging several hundred metres thicker ice across the Bay between 45 and 32 ka. Thus, ice must either have been thicker immediately inland (with a steeper ice profile), or there were additional ice domes on the shallow banks of the outer continental shelf. Further work is required to reconcile the differences between empirical evidence of past ice sheet histories, and the history predicted by ice sheet models from far-field temperature and sea level records.
    Original languageEnglish
    Pages (from-to)1-10
    Number of pages10
    JournalQuaternary Science Reviews
    Volume153
    DOIs
    Publication statusPublished - 2016

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    Antarctica
    marine isotope stage
    Last Glacial
    ice sheet
    isotopes
    ice
    evidence
    Group
    history
    lacustrine deposit
    continental shelf
    sea level
    bank
    ice retreat
    climate
    mathematics
    Continental
    Sea Level
    History
    Isotopes

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    Berg, Sonja ; WHITE, Duanne ; Bennike, Ole ; Fülöp, Reka-Hajnalka ; Fink, David ; Wagner, Bernd ; Melles, Martin. / Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) – New evidence from Rauer Group. In: Quaternary Science Reviews. 2016 ; Vol. 153. pp. 1-10.
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    title = "Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) – New evidence from Rauer Group",
    abstract = "Limited information on the East Antarctic Ice Sheet (EAIS) geometry during Marine Isotope Stage 3 (MIS 3; 60-25 ka) restricts our understanding of its behaviour during periods of climate and sea level change. Ice sheet models forced by global parameters suggest an expanded EAIS compared to the Holocene during MIS 3, but field evidence from East Antarctic coastal areas contradicts such modelling, and suggests that the ice sheet margins were no more advanced than at present. Here we present a new lake sediment record, and cosmogenic exposure results from bedrock, which confirm that Rauer Group (eastern Prydz Bay) was ice-free for much of MIS 3. We also refine the likely duration of the Last Glacial Maximum (LGM) glaciation in the region. Lacustrine and marine sediments from Rauer Group indicate the penultimate period of ice retreat predates 50 ka. The lacustrine record indicates a change from warmer/wetter conditions to cooler/drier conditions after ca. 35 ka. Substantive ice sheet re-advance, however, may not have occurred until much closer to 20 ka. Contemporary coastal areas were still connected to the sea during MIS 3, restricting the possible extent of grounded ice in Prydz Bay on the continental shelf. In contrast, relative sea levels (RSL) deduced from field evidence indicate an extra ice load averaging several hundred metres thicker ice across the Bay between 45 and 32 ka. Thus, ice must either have been thicker immediately inland (with a steeper ice profile), or there were additional ice domes on the shallow banks of the outer continental shelf. Further work is required to reconcile the differences between empirical evidence of past ice sheet histories, and the history predicted by ice sheet models from far-field temperature and sea level records.",
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    year = "2016",
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    Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) – New evidence from Rauer Group. / Berg, Sonja; WHITE, Duanne; Bennike, Ole; Fülöp, Reka-Hajnalka; Fink, David; Wagner, Bernd; Melles, Martin.

    In: Quaternary Science Reviews, Vol. 153, 2016, p. 1-10.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Unglaciated areas in East Antarctica during the Last Glacial (Marine Isotope Stage 3) – New evidence from Rauer Group

    AU - Berg, Sonja

    AU - WHITE, Duanne

    AU - Bennike, Ole

    AU - Fülöp, Reka-Hajnalka

    AU - Fink, David

    AU - Wagner, Bernd

    AU - Melles, Martin

    PY - 2016

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    N2 - Limited information on the East Antarctic Ice Sheet (EAIS) geometry during Marine Isotope Stage 3 (MIS 3; 60-25 ka) restricts our understanding of its behaviour during periods of climate and sea level change. Ice sheet models forced by global parameters suggest an expanded EAIS compared to the Holocene during MIS 3, but field evidence from East Antarctic coastal areas contradicts such modelling, and suggests that the ice sheet margins were no more advanced than at present. Here we present a new lake sediment record, and cosmogenic exposure results from bedrock, which confirm that Rauer Group (eastern Prydz Bay) was ice-free for much of MIS 3. We also refine the likely duration of the Last Glacial Maximum (LGM) glaciation in the region. Lacustrine and marine sediments from Rauer Group indicate the penultimate period of ice retreat predates 50 ka. The lacustrine record indicates a change from warmer/wetter conditions to cooler/drier conditions after ca. 35 ka. Substantive ice sheet re-advance, however, may not have occurred until much closer to 20 ka. Contemporary coastal areas were still connected to the sea during MIS 3, restricting the possible extent of grounded ice in Prydz Bay on the continental shelf. In contrast, relative sea levels (RSL) deduced from field evidence indicate an extra ice load averaging several hundred metres thicker ice across the Bay between 45 and 32 ka. Thus, ice must either have been thicker immediately inland (with a steeper ice profile), or there were additional ice domes on the shallow banks of the outer continental shelf. Further work is required to reconcile the differences between empirical evidence of past ice sheet histories, and the history predicted by ice sheet models from far-field temperature and sea level records.

    AB - Limited information on the East Antarctic Ice Sheet (EAIS) geometry during Marine Isotope Stage 3 (MIS 3; 60-25 ka) restricts our understanding of its behaviour during periods of climate and sea level change. Ice sheet models forced by global parameters suggest an expanded EAIS compared to the Holocene during MIS 3, but field evidence from East Antarctic coastal areas contradicts such modelling, and suggests that the ice sheet margins were no more advanced than at present. Here we present a new lake sediment record, and cosmogenic exposure results from bedrock, which confirm that Rauer Group (eastern Prydz Bay) was ice-free for much of MIS 3. We also refine the likely duration of the Last Glacial Maximum (LGM) glaciation in the region. Lacustrine and marine sediments from Rauer Group indicate the penultimate period of ice retreat predates 50 ka. The lacustrine record indicates a change from warmer/wetter conditions to cooler/drier conditions after ca. 35 ka. Substantive ice sheet re-advance, however, may not have occurred until much closer to 20 ka. Contemporary coastal areas were still connected to the sea during MIS 3, restricting the possible extent of grounded ice in Prydz Bay on the continental shelf. In contrast, relative sea levels (RSL) deduced from field evidence indicate an extra ice load averaging several hundred metres thicker ice across the Bay between 45 and 32 ka. Thus, ice must either have been thicker immediately inland (with a steeper ice profile), or there were additional ice domes on the shallow banks of the outer continental shelf. Further work is required to reconcile the differences between empirical evidence of past ice sheet histories, and the history predicted by ice sheet models from far-field temperature and sea level records.

    KW - Antarctica

    KW - Exposure dating

    KW - Ice sheet reconstructions

    KW - Lake sediments

    U2 - 10.1016/j.quascirev.2016.08.021

    DO - 10.1016/j.quascirev.2016.08.021

    M3 - Article

    VL - 153

    SP - 1

    EP - 10

    JO - Quaternary Science Reviews

    JF - Quaternary Science Reviews

    SN - 0277-3791

    ER -