Potential Antarctic Ice Sheet retreat driven by hydrofracturing and ice cliff failure

  title={Potential Antarctic Ice Sheet retreat driven by hydrofracturing and ice cliff failure},
  author={David D. Pollard and Robert M. DeConto and Richard B. Alley},
  journal={Earth and Planetary Science Letters},
Abstract Geological data indicate that global mean sea level has fluctuated on 103 to 106 yr time scales during the last ∼25 million years, at times reaching 20 m or more above modern. If correct, this implies substantial variations in the size of the East Antarctic Ice Sheet (EAIS). However, most climate and ice sheet models have not been able to simulate significant EAIS retreat from continental size, given that atmospheric CO2 levels were relatively low throughout this period. Here, we use a… Expand

Figures from this paper

Repeated large-scale retreat and advance of Totten Glacier indicated by inland bed erosion
Demarcate the marginal zones of two distinct quasi-stable EAIS configurations, corresponding to the ‘modern-scale’ ice sheet and the retreated ice sheet, suggesting shorter-lived exposure to eroding conditions during repeated retreat–advance events, which are probably driven by ocean-forced instabilities. Expand
Revisiting Antarctic ice loss due to marine ice-cliff instability
It is concluded that previous interpretations of these MICI projections over-estimate sea-level rise this century; because the MICI hypothesis is not well constrained, confidence in projections with MICI would require a greater range of observationally constrained models of ice-shelf vulnerability and ice-cliff collapse. Expand
Ocean temperature thresholds for Last Interglacial West Antarctic Ice Sheet collapse
The West Antarctic Ice Sheet (WAIS) is considered the major contributor to global sea level rise in the Last Interglacial (LIG) and potentially in the future. Exposed fossil reef terraces suggest seaExpand
Oceanic Forcing of Ice-Sheet Retreat: West Antarctica and More
Ocean-ice interactions have exerted primary control on the Antarctic Ice Sheet and parts of the Greenland Ice Sheet, and will continue to do so in the near future, especially through melting of iceExpand
Potential sea-level rise from Antarctic ice-sheet instability constrained by observations
It is suggested that upper-bound estimates from low-resolution models and physical arguments are implausible under current understanding of physical mechanisms and potential triggers of marine-ice-sheet instability. Expand
Dynamic Antarctic ice sheet during the early to mid-Miocene
This work simulates large-scale variability of the early to mid-Miocene Antarctic ice sheet using a climate–ice sheet coupling method utilizing a high-resolution atmospheric component to account for ice sheet–climate feedbacks and accounts for changes in the oxygen isotopic composition of the ice sheet by using isotope-enabled climate and ice sheet models. Expand
Millennial‐Scale Vulnerability of the Antarctic Ice Sheet to Regional Ice Shelf Collapse
Author(s): Martin, DF; Cornford, SL; Payne, AJ | Abstract: ©2019. American Geophysical Union. All Rights Reserved. The Antarctic Ice Sheet (AIS) remains the largest uncertainty in projections ofExpand
Oligocene Wilkes Land sea surface temperature Antarctic ice sheet 10
The volume of the Antarctic continental ice sheet(s) varied substantially during the Oligocene and 25 Miocene (~34-5 Ma) from smaller to substantially larger than today, both on million-year and onExpand
Bedrock Erosion Surfaces Record Former East Antarctic Ice Sheet Extent
East Antarctica hosts large subglacial basins into which the East Antarctic Ice Sheet (EAIS) likely retreated during past warmer climates. However, the extent of retreat remains poorly constrained,Expand
Continuous simulations over the last 40 million years with a coupled Antarctic ice sheet-sediment model
Abstract Much of the knowledge of Antarctic Ice Sheet variations since its inception ~34 Ma derives from marine sediments on the continental shelf, deposited in glacimarine or sub-ice environments byExpand


Modelling West Antarctic ice sheet growth and collapse through the past five million years
A combined ice sheet/ice shelf model capable of high-resolution nesting with a new treatment of grounding-line dynamics and ice-shelf buttressing is used to simulate Antarctic ice sheet variations over the past five million years, indicating a long-term trend from more frequently collapsed to more glaciated states. Expand
A dynamic early East Antarctic Ice Sheet suggested by ice-covered fjord landscapes
The identification of this fjord landscape, based on new data from ice-penetrating radar, provides an improved understanding of the topography of the Aurora Subglacial Basin and its surroundings, and reveals a complex surface sculpted by a succession of ice-sheet configurations substantially different from today's. Expand
Hysteresis in Cenozoic Antarctic ice-sheet variations
A coupled global climate–Antarctic ice sheet model is run for 10 million years across the Eocene–Oligocene boundary ~34 Ma. The model simulates a rapid transition from very little ice to a largeExpand
Collapse of polar ice sheets during the stage 11 interglacial
It is estimated that eustatic sea level rose to ∼6–13 m above the present-day value in the second half of MIS 11, which suggests that both the Greenland Ice Sheet and the West Antarctic Ice Sheet collapsed during the protracted warm period while changes in the volume of the East Antarctic Ice sheet were relatively minor. Expand
Glaciological modelling of the late Cenozoic East Antarctic ice sheet: Stability or dynamism?
On the basis of geological arguments, two widely different hypotheses have been proposed for the late-Tertiary glacial history of East Antarctica. Theseinvoke ice-sheet reconstructions ranging fromExpand
Modeling Antarctic ice sheet and climate variations during Marine Isotope Stage 31
Abstract Marine Isotope Stage 31 (MIS-31) is one of the major interglacials of the early Pleistocene ~ 1.08 to 1.06 Ma. Data from proximal sediment cores around several sectors of Antarctica indicateExpand
History of the Greenland Ice Sheet: paleoclimatic insights
Abstract Paleoclimatic records show that the Greenland Ice Sheet consistently has lost mass in response to warming, and grown in response to cooling. Such changes have occurred even at times of slowExpand
Obliquity-paced Pliocene West Antarctic ice sheet oscillations
A marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf is presented and well-dated, ∼40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth’s axial tilt (obliquity) during the Pliocene are demonstrated. Expand
Effect of orbital‐scale climate cycling and meltwater drainage on ice sheet grounding line migration
[1] Ice shelf response to climate cycling introduces hysteretic behavior in outlet glaciers, with the evolution of meltwater drainage networks enhancing this effect. The 2002 collapse of the Larsen BExpand
Dynamic behaviour of the East Antarctic ice sheet during Pliocene warmth
Warm intervals within the Pliocene epoch (5.33–2.58 million years ago) were characterized by global temperatures comparable to those predicted for the end of this century1 and atmospheric CO2Expand