A synthesis of remote sensing data on Wilkins Ice Shelf, Antarctica

Vaughan, David G.; Mantripp, D. R.; Sievers, Jörn; Doake, C. S. M.

doi:10.1017/s0260305500012866

Cited by 25 publications

(20 citation statements)

References 14 publications

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“…It is almost certainly insufficient to give a more precise predictive capacity for any individual ice shelf. The prediction by Vaughan et al (1993) that Wilkins Ice Shelf would collapse in thirty years was arguably 50% wrong, in that much of this ice shelf has already been lost. However, it is questionable whether that ad hoc prediction could be much improved today.…”

Section: Discussionmentioning

confidence: 99%

Overview of areal changes of the ice shelves on the Antarctic Peninsula over the past 50 years

2010

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Abstract. In recent decades, seven out of twelve ice shelves around the Antarctic Peninsula (AP) have either retreated significantly or have been almost entirely lost. At least some of these retreats have been shown to be unusual within the context of the Holocene and have been widely attributed to recent atmospheric and oceanic changes. To date, measurements of the area of ice shelves on the AP have either been approximated, or calculated for individual shelves over dissimilar time intervals. Here we present a new dataset containing up-to-date and consistent area calculations for each of the twelve ice shelves on the AP over the past five decades. The results reveal an overall reduction in total ice-shelf area by over 28 000 km 2 since the beginning of the period. Individual ice shelves show different rates of retreat, ranging from slow but progressive retreat to abrupt collapse. We discuss the pertinent features of each ice shelf and also broad spatial and temporal patterns in the timing and rate of retreat. We believe that an understanding of this diversity and what it implies about the underlying dynamics and control will provide the best foundation for developing a reliable predictive skill for ice-shelf change.

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Section: Discussionmentioning

confidence: 99%

Overview of areal changes of the ice shelves on the Antarctic Peninsula over the past 50 years

2010

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“…The latter has been observed in the Wilkins Ice Shelf [ Vaughan et al . ] and is common for sea ice as well in the form of flooding of snow‐covered ice floes [e.g., Massom et al ., ]. In the case of brine infiltration in an ice shelf, a meteoric ice body is present below the reflector and it would therefore be impossible to determine the thickness of a deeper marine ice layer from elevation data.…”

Section: Discussionmentioning

confidence: 99%

Marine ice formation in a suture zone on the Larsen C Ice Shelf and its influence on ice shelf dynamics

et al. 2013

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[1] Antarctic ice shelves are fed primarily by the glaciers flowing into them. Downstream of promontories separating these glaciers, supercooled water can rise and freeze into suture zones, leading to the accretion of marine ice. Marine ice bodies have been found in several Antarctic ice shelves, but little is known about their detailed geometry, rate of accretion, or influence on ice dynamics. In this study, we investigate marine ice in a suture zone downstream of the Joerg Peninsula in the southern part of the Larsen C Ice Shelf, Antarctic Peninsula. We present ground penetrating radar data from which we infer the base of the meteoric ice and, in combination with GPS data and assuming hydrostatic equilibrium, estimate marine ice thickness within a suture zone. We show that the Joerg Peninsula suture zone contains marine ice layer, which is increasing in thickness along flow from~140 m to 180 m over 20 km, implying an average basal accretion rate of 0.5 m a À1 in our study area. We examined the impact of this inferred marine ice on ice shelf dynamics by modeling the suture zone within an ice flow model. The results, which replicate observed surface velocities and strain rates, show that the warmer and thus softer ice of the suture zone serves to channel shear deformation. This enables decoupling of neighboring flow units with different flow velocities, while maintaining the structural integrity of the ice shelf.

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“…Normally, the temperature inside an ice shelf remains close to the mean annual air temperature (see, Paterson, 1994), but if melt water is produced at the surface, it can percolate down into the ice (either through the porous ice, Vaughan et al, 1993;or within crevasses, see, Scambos et al, 2000). When this water refreezes the latent heat released can raise the temperature of considerable volumes of ice to the melting point.…”

Section: Deconstructing Mercer's Paradigmmentioning

confidence: 99%

West Antarctic Ice Sheet collapse – the fall and rise of a paradigm

Vaughan

2008

Climatic Change

115

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It is now almost 30 years since John Mercer (1978) first presented the idea that climate change could eventually cause a rapid deglaciation, or "collapse", of a large part of the West Antarctic ice sheet (WAIS), raising world sea levels by 5 metres and causing untold economic and social impacts. This idea, apparently simple and scientifically plausible, created a vision of the future, sufficiently alarming that it became a paradigm for a generation of researchers and provided an icon for the green movement. Through the 1990s, however, a lack of observational evidence for ongoing retreat in WAIS and improved understanding of the complex dynamics of ice streams meant that estimates of likelihood of collapse seemed to be diminishing. In the last few years, however, satellite studies over the apparently inaccessible Amundsen Sea sector of West Antarctica have shown clear evidence of ice sheet retreat showing all the features that might have been predicted for emergent collapse. These studies are re-invigorating the paradigm, albeit in a modified form, and debate about the future stability of WAIS. Since much of WAIS appears to be stable, it may, no longer be reasonable to suggest there is an imminent threat of a 5-m rise in sea level resulting from complete collapse of the West Antarctic ice sheet, but there is strong evidence that the Amundsen Sea embayment is changing rapidly. This area alone, contains the potential to raise sea level by around ~1.5 m, but more importantly it seems likely that it could, alter rapidly enough, to make a significant addition to the rate of sea-level rise over coming two centuries. Furthermore, a plausible connection between contemporary climate change and the fate of the ice sheet appears to be developing. The return of the paradigm presents a dilemma for policy-makers, and establishes a renewed set of priorities for the glaciological community. In particular, we must establish whether the hypothesized instability in WAIS is real, or simply an oversimplification resulting from inadequate understanding of the feedbacks that allow ice sheets to achieve equilibrium: and whether there is any likelihood that contemporary climate change could initiate collapse.

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A synthesis of remote sensing data on Wilkins Ice Shelf, Antarctica

Cited by 25 publications

References 14 publications

Overview of areal changes of the ice shelves on the Antarctic Peninsula over the past 50 years

Overview of areal changes of the ice shelves on the Antarctic Peninsula over the past 50 years

Marine ice formation in a suture zone on the Larsen C Ice Shelf and its influence on ice shelf dynamics

West Antarctic Ice Sheet collapse – the fall and rise of a paradigm

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