Was South Georgia covered by an ice cap during the Last Glacial Maximum?

Duanne WHITE, Ole Bennike, Martin Melles, Sonja Berg, Steven Binnie

    Research output: Contribution to Newspaper/Magazine/BulletinArticle

    4 Citations (Scopus)

    Abstract

    The behaviour of ice caps and glaciers on sub-Antarctic islands during previous periods of warming provide key empirical evidence for understanding the behaviour of marine ice sheets in the future. However, the extent of ice on sub-Antarctic islands during the last 100 kyr is poorly constrained. Here, we investigate the past glacial extents on South Georgia, where previous Last Glacial Maximum (LGM) reconstructions vary between small fjord-terminating glaciers and a large marine-based ice sheet. To help resolve this uncertainty, we apply Schmidt hammer relative-age dating to measure rock hardness and, thus, exposure age of a range of glacial deposits. Applying a hardness–age calibration curve constructed from well-dated Holocene, late-glacial deposits and terminal LGM deposits, we determine that deglaciation of the approximately 600 m-high peaks on the outer Lewin Peninsula occurred during the latter half of the last glacial stage, and probably the end of the LGM. We infer that South Georgia was covered by a marine-based ice cap during the latter part of the last glacial stage
    Original languageEnglish
    Pages49-59
    Number of pages10
    Volume461
    Specialist publicationGeological Society Special Publication
    PublisherGeological Society of London
    DOIs
    Publication statusPublished - 2018

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    ice cap
    Last Glacial Maximum
    glacial deposit
    Last Glacial
    ice sheet
    glacier
    late glacial
    fjord
    deglaciation
    hardness
    warming
    Holocene
    calibration
    ice
    rock

    Cite this

    WHITE, Duanne ; Bennike, Ole ; Melles, Martin ; Berg, Sonja ; Binnie, Steven. / Was South Georgia covered by an ice cap during the Last Glacial Maximum?. In: Geological Society Special Publication. 2018 ; Vol. 461. pp. 49-59.
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    title = "Was South Georgia covered by an ice cap during the Last Glacial Maximum?",
    abstract = "The behaviour of ice caps and glaciers on sub-Antarctic islands during previous periods of warming provide key empirical evidence for understanding the behaviour of marine ice sheets in the future. However, the extent of ice on sub-Antarctic islands during the last 100 kyr is poorly constrained. Here, we investigate the past glacial extents on South Georgia, where previous Last Glacial Maximum (LGM) reconstructions vary between small fjord-terminating glaciers and a large marine-based ice sheet. To help resolve this uncertainty, we apply Schmidt hammer relative-age dating to measure rock hardness and, thus, exposure age of a range of glacial deposits. Applying a hardness–age calibration curve constructed from well-dated Holocene, late-glacial deposits and terminal LGM deposits, we determine that deglaciation of the approximately 600 m-high peaks on the outer Lewin Peninsula occurred during the latter half of the last glacial stage, and probably the end of the LGM. We infer that South Georgia was covered by a marine-based ice cap during the latter part of the last glacial stage",
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    Was South Georgia covered by an ice cap during the Last Glacial Maximum? / WHITE, Duanne; Bennike, Ole; Melles, Martin; Berg, Sonja; Binnie, Steven.

    In: Geological Society Special Publication, Vol. 461, 2018, p. 49-59.

    Research output: Contribution to Newspaper/Magazine/BulletinArticle

    TY - GEN

    T1 - Was South Georgia covered by an ice cap during the Last Glacial Maximum?

    AU - WHITE, Duanne

    AU - Bennike, Ole

    AU - Melles, Martin

    AU - Berg, Sonja

    AU - Binnie, Steven

    PY - 2018

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    AB - The behaviour of ice caps and glaciers on sub-Antarctic islands during previous periods of warming provide key empirical evidence for understanding the behaviour of marine ice sheets in the future. However, the extent of ice on sub-Antarctic islands during the last 100 kyr is poorly constrained. Here, we investigate the past glacial extents on South Georgia, where previous Last Glacial Maximum (LGM) reconstructions vary between small fjord-terminating glaciers and a large marine-based ice sheet. To help resolve this uncertainty, we apply Schmidt hammer relative-age dating to measure rock hardness and, thus, exposure age of a range of glacial deposits. Applying a hardness–age calibration curve constructed from well-dated Holocene, late-glacial deposits and terminal LGM deposits, we determine that deglaciation of the approximately 600 m-high peaks on the outer Lewin Peninsula occurred during the latter half of the last glacial stage, and probably the end of the LGM. We infer that South Georgia was covered by a marine-based ice cap during the latter part of the last glacial stage

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    PB - Geological Society of London

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