Ice-shelf collapse from subsurface warming as a trigger for Heinrich events

Shaun A. Marcott, Peter U Clark, Laurie Padman, Gary P. Klinkhammer, Scott R. Springer, Zhengyu Liu, Bette L. Otto-Bliesner, Anders E. Carlson, Andy Ungerer, June Padman, Feng He, Jun Cheng, Andreas Schmittner

    Research output: Contribution to journalArticle

    168 Citations (Scopus)

    Abstract

    Episodic iceberg-discharge events from the Hudson Strait Ice Stream (HSIS) of the Laurentide Ice Sheet, referred to as Heinrich events, are commonly attributed to internal ice-sheet instabilities, but their systematic occurrence at the culmination of a large reduction in the Atlantic meridional overturning circulation (AMOC) indicates a climate control. We report Mg/Ca data on benthic foraminifera from an intermediate-depth site in the northwest Atlantic and results from a climate-model simulation that reveal basin-wide subsurface warming at the same time as large reductions in the AMOC, with temperature increasing by approximately 2 °C over a 1–2 kyr interval prior to a Heinrich event. In simulations with an ocean model coupled to a thermodynamically active ice shelf, the increase in subsurface temperature increases basal melt rate under an ice shelf fronting the HSIS by a factor of approximately 6. By analogy with recent observations in Antarctica, the resulting ice-shelf loss and attendant HSIS acceleration would produce a Heinrich event.
    LanguageEnglish
    Pages13415-13419
    JournalPROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
    Volume108
    Issue number33
    DOIs
    Publication statusPublished - Aug 2011

    Fingerprint

    Heinrich event
    ice stream
    ice shelf
    strait
    warming
    meridional circulation
    Laurentide Ice Sheet
    iceberg
    benthic foraminifera
    simulation
    ice sheet
    climate modeling
    temperature
    melt
    climate
    ocean
    basin

    Cite this

    Marcott, Shaun A. ; Clark, Peter U ; Padman, Laurie ; Klinkhammer, Gary P. ; Springer, Scott R. ; Liu, Zhengyu ; Otto-Bliesner, Bette L. ; Carlson, Anders E. ; Ungerer, Andy ; Padman, June ; He, Feng ; Cheng, Jun ; Schmittner, Andreas. / Ice-shelf collapse from subsurface warming as a trigger for Heinrich events. In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. 2011 ; Vol. 108, No. 33. pp. 13415-13419.
    @article{1b440e58db0545358b9052c5491668e0,
    title = "Ice-shelf collapse from subsurface warming as a trigger for Heinrich events",
    abstract = "Episodic iceberg-discharge events from the Hudson Strait Ice Stream (HSIS) of the Laurentide Ice Sheet, referred to as Heinrich events, are commonly attributed to internal ice-sheet instabilities, but their systematic occurrence at the culmination of a large reduction in the Atlantic meridional overturning circulation (AMOC) indicates a climate control. We report Mg/Ca data on benthic foraminifera from an intermediate-depth site in the northwest Atlantic and results from a climate-model simulation that reveal basin-wide subsurface warming at the same time as large reductions in the AMOC, with temperature increasing by approximately 2 °C over a 1–2 kyr interval prior to a Heinrich event. In simulations with an ocean model coupled to a thermodynamically active ice shelf, the increase in subsurface temperature increases basal melt rate under an ice shelf fronting the HSIS by a factor of approximately 6. By analogy with recent observations in Antarctica, the resulting ice-shelf loss and attendant HSIS acceleration would produce a Heinrich event.",
    author = "Marcott, {Shaun A.} and Clark, {Peter U} and Laurie Padman and Klinkhammer, {Gary P.} and Springer, {Scott R.} and Zhengyu Liu and Otto-Bliesner, {Bette L.} and Carlson, {Anders E.} and Andy Ungerer and June Padman and Feng He and Jun Cheng and Andreas Schmittner",
    year = "2011",
    month = "8",
    doi = "10.1073/pnas.1104772108",
    language = "English",
    volume = "108",
    pages = "13415--13419",
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    Marcott, SA, Clark, PU, Padman, L, Klinkhammer, GP, Springer, SR, Liu, Z, Otto-Bliesner, BL, Carlson, AE, Ungerer, A, Padman, J, He, F, Cheng, J & Schmittner, A 2011, 'Ice-shelf collapse from subsurface warming as a trigger for Heinrich events', PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, vol. 108, no. 33, pp. 13415-13419. https://doi.org/10.1073/pnas.1104772108

    Ice-shelf collapse from subsurface warming as a trigger for Heinrich events. / Marcott, Shaun A.; Clark, Peter U; Padman, Laurie; Klinkhammer, Gary P.; Springer, Scott R.; Liu, Zhengyu; Otto-Bliesner, Bette L.; Carlson, Anders E.; Ungerer, Andy; Padman, June; He, Feng; Cheng, Jun; Schmittner, Andreas.

    In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Vol. 108, No. 33, 08.2011, p. 13415-13419.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Ice-shelf collapse from subsurface warming as a trigger for Heinrich events

    AU - Marcott, Shaun A.

    AU - Clark, Peter U

    AU - Padman, Laurie

    AU - Klinkhammer, Gary P.

    AU - Springer, Scott R.

    AU - Liu, Zhengyu

    AU - Otto-Bliesner, Bette L.

    AU - Carlson, Anders E.

    AU - Ungerer, Andy

    AU - Padman, June

    AU - He, Feng

    AU - Cheng, Jun

    AU - Schmittner, Andreas

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    N2 - Episodic iceberg-discharge events from the Hudson Strait Ice Stream (HSIS) of the Laurentide Ice Sheet, referred to as Heinrich events, are commonly attributed to internal ice-sheet instabilities, but their systematic occurrence at the culmination of a large reduction in the Atlantic meridional overturning circulation (AMOC) indicates a climate control. We report Mg/Ca data on benthic foraminifera from an intermediate-depth site in the northwest Atlantic and results from a climate-model simulation that reveal basin-wide subsurface warming at the same time as large reductions in the AMOC, with temperature increasing by approximately 2 °C over a 1–2 kyr interval prior to a Heinrich event. In simulations with an ocean model coupled to a thermodynamically active ice shelf, the increase in subsurface temperature increases basal melt rate under an ice shelf fronting the HSIS by a factor of approximately 6. By analogy with recent observations in Antarctica, the resulting ice-shelf loss and attendant HSIS acceleration would produce a Heinrich event.

    AB - Episodic iceberg-discharge events from the Hudson Strait Ice Stream (HSIS) of the Laurentide Ice Sheet, referred to as Heinrich events, are commonly attributed to internal ice-sheet instabilities, but their systematic occurrence at the culmination of a large reduction in the Atlantic meridional overturning circulation (AMOC) indicates a climate control. We report Mg/Ca data on benthic foraminifera from an intermediate-depth site in the northwest Atlantic and results from a climate-model simulation that reveal basin-wide subsurface warming at the same time as large reductions in the AMOC, with temperature increasing by approximately 2 °C over a 1–2 kyr interval prior to a Heinrich event. In simulations with an ocean model coupled to a thermodynamically active ice shelf, the increase in subsurface temperature increases basal melt rate under an ice shelf fronting the HSIS by a factor of approximately 6. By analogy with recent observations in Antarctica, the resulting ice-shelf loss and attendant HSIS acceleration would produce a Heinrich event.

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    DO - 10.1073/pnas.1104772108

    M3 - Article

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    JO - Proceedings of the National Academy of Sciences

    T2 - Proceedings of the National Academy of Sciences

    JF - Proceedings of the National Academy of Sciences

    SN - 0027-8424

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    ER -