Threshold behavior of a marine-based sector of the East Antarctic Ice Sheet in response to early Pliocene ocean warming

Melissa A. Hansen, Sandra Passchier, Boo Keun Khim, Buhan Song, Trevor Williams

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We investigate the stability of the East Antarctic Ice Sheet (EAIS) on the Wilkes Land continental margin, Antarctica, utilizing a high-resolution record of ice-rafted debris (IRD) mass accumulation rates (MAR) from Integrated Ocean Drilling Program Site U1359. The relationship between orbital variations in the IRD record and climate drivers was evaluated to capture changes in the dynamics of a marine-based ice sheet in response to early Pliocene warming. Three IRD MAR excursions were observed and confirmed via scanning electron microscope microtextural analysis of sand grains. Time series analysis of the IRD MAR reveals obliquity-paced expansions of the ice sheet to the outer shelf prior to ∼4.6 Ma. A decline in the obliquity and a transition into a dominant precession response of IRD MAR occur at ∼4.6 Ma along with a decline in the amplitude of IRD MAR maxima to low background levels between ∼4.0 and ∼3.5 Ma. We speculate that as sea surface temperatures began to peak above 3°C during the early Pliocene climatic optimum, the ice shelves thinned, leading to a greater susceptibility to precession-forced summer insolation and the onset of persistent retreat of a marine-based portion of the EAIS.

Original languageEnglish
Pages (from-to)789-801
Number of pages13
JournalPaleoceanography
Volume30
Issue number6
DOIs
StatePublished - 1 Jun 2015

Fingerprint

ice-rafted debris
ice sheet
Pliocene
accumulation rate
warming
ocean
obliquity
precession
Hypsithermal
ice shelf
time series analysis
background level
insolation
Ocean Drilling Program
continental margin
sea surface temperature
electron
sand
climate
summer

Keywords

  • Antarctica
  • IRD MAR
  • Pliocene
  • Southern Ocean
  • climate variability
  • orbital insolation

Cite this

Hansen, Melissa A. ; Passchier, Sandra ; Khim, Boo Keun ; Song, Buhan ; Williams, Trevor. / Threshold behavior of a marine-based sector of the East Antarctic Ice Sheet in response to early Pliocene ocean warming. In: Paleoceanography. 2015 ; Vol. 30, No. 6. pp. 789-801.
@article{744f03a90c2e4f11bfbf17a683030ae8,
title = "Threshold behavior of a marine-based sector of the East Antarctic Ice Sheet in response to early Pliocene ocean warming",
abstract = "We investigate the stability of the East Antarctic Ice Sheet (EAIS) on the Wilkes Land continental margin, Antarctica, utilizing a high-resolution record of ice-rafted debris (IRD) mass accumulation rates (MAR) from Integrated Ocean Drilling Program Site U1359. The relationship between orbital variations in the IRD record and climate drivers was evaluated to capture changes in the dynamics of a marine-based ice sheet in response to early Pliocene warming. Three IRD MAR excursions were observed and confirmed via scanning electron microscope microtextural analysis of sand grains. Time series analysis of the IRD MAR reveals obliquity-paced expansions of the ice sheet to the outer shelf prior to ∼4.6 Ma. A decline in the obliquity and a transition into a dominant precession response of IRD MAR occur at ∼4.6 Ma along with a decline in the amplitude of IRD MAR maxima to low background levels between ∼4.0 and ∼3.5 Ma. We speculate that as sea surface temperatures began to peak above 3°C during the early Pliocene climatic optimum, the ice shelves thinned, leading to a greater susceptibility to precession-forced summer insolation and the onset of persistent retreat of a marine-based portion of the EAIS.",
keywords = "Antarctica, IRD MAR, Pliocene, Southern Ocean, climate variability, orbital insolation",
author = "Hansen, {Melissa A.} and Sandra Passchier and Khim, {Boo Keun} and Buhan Song and Trevor Williams",
year = "2015",
month = "6",
day = "1",
doi = "10.1002/2014PA002704",
language = "English",
volume = "30",
pages = "789--801",
journal = "Paleoceanography",
issn = "0883-8305",
publisher = "Wiley-Blackwell",
number = "6",

}

Threshold behavior of a marine-based sector of the East Antarctic Ice Sheet in response to early Pliocene ocean warming. / Hansen, Melissa A.; Passchier, Sandra; Khim, Boo Keun; Song, Buhan; Williams, Trevor.

In: Paleoceanography, Vol. 30, No. 6, 01.06.2015, p. 789-801.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Threshold behavior of a marine-based sector of the East Antarctic Ice Sheet in response to early Pliocene ocean warming

AU - Hansen, Melissa A.

AU - Passchier, Sandra

AU - Khim, Boo Keun

AU - Song, Buhan

AU - Williams, Trevor

PY - 2015/6/1

Y1 - 2015/6/1

N2 - We investigate the stability of the East Antarctic Ice Sheet (EAIS) on the Wilkes Land continental margin, Antarctica, utilizing a high-resolution record of ice-rafted debris (IRD) mass accumulation rates (MAR) from Integrated Ocean Drilling Program Site U1359. The relationship between orbital variations in the IRD record and climate drivers was evaluated to capture changes in the dynamics of a marine-based ice sheet in response to early Pliocene warming. Three IRD MAR excursions were observed and confirmed via scanning electron microscope microtextural analysis of sand grains. Time series analysis of the IRD MAR reveals obliquity-paced expansions of the ice sheet to the outer shelf prior to ∼4.6 Ma. A decline in the obliquity and a transition into a dominant precession response of IRD MAR occur at ∼4.6 Ma along with a decline in the amplitude of IRD MAR maxima to low background levels between ∼4.0 and ∼3.5 Ma. We speculate that as sea surface temperatures began to peak above 3°C during the early Pliocene climatic optimum, the ice shelves thinned, leading to a greater susceptibility to precession-forced summer insolation and the onset of persistent retreat of a marine-based portion of the EAIS.

AB - We investigate the stability of the East Antarctic Ice Sheet (EAIS) on the Wilkes Land continental margin, Antarctica, utilizing a high-resolution record of ice-rafted debris (IRD) mass accumulation rates (MAR) from Integrated Ocean Drilling Program Site U1359. The relationship between orbital variations in the IRD record and climate drivers was evaluated to capture changes in the dynamics of a marine-based ice sheet in response to early Pliocene warming. Three IRD MAR excursions were observed and confirmed via scanning electron microscope microtextural analysis of sand grains. Time series analysis of the IRD MAR reveals obliquity-paced expansions of the ice sheet to the outer shelf prior to ∼4.6 Ma. A decline in the obliquity and a transition into a dominant precession response of IRD MAR occur at ∼4.6 Ma along with a decline in the amplitude of IRD MAR maxima to low background levels between ∼4.0 and ∼3.5 Ma. We speculate that as sea surface temperatures began to peak above 3°C during the early Pliocene climatic optimum, the ice shelves thinned, leading to a greater susceptibility to precession-forced summer insolation and the onset of persistent retreat of a marine-based portion of the EAIS.

KW - Antarctica

KW - IRD MAR

KW - Pliocene

KW - Southern Ocean

KW - climate variability

KW - orbital insolation

UR - http://www.scopus.com/inward/record.url?scp=84947490614&partnerID=8YFLogxK

U2 - 10.1002/2014PA002704

DO - 10.1002/2014PA002704

M3 - Article

AN - SCOPUS:84947490614

VL - 30

SP - 789

EP - 801

JO - Paleoceanography

JF - Paleoceanography

SN - 0883-8305

IS - 6

ER -