AGU: Geophysical Research Letters

 

Editors' Highlight

Past ice elevations in the West Antarctic Ice Sheet

Observations of dramatic loss of ice shelves and acceleration of outlet glaciers in Antarctica have caused scientists to worry about whether the West Antarctic Ice Sheet (WAIS) is susceptible to rapid collapse in response to warmer sea and air temperatures. Moreover, recent field results indicate that for about the past 8000 years, the WAIS has retreated without substantial sea level or climate forcing. This suggests that current ice loss trends could continue in the absence of further external forcing and that current estimates of sea level rise may be underestimated. Noting that a prerequisite to predicting the response of the WAIS to future climate changes is successfully simulating past WAIS history, Ackert et al. (2007) sought to better quantify benchmarks for these models, such as past ice elevations, in key areas of the WAIS. They found that cosmogenic exposure ages of glacial boulders show that about 11,000 years ago, the WAIS high-stand near the ice divide was about 125 m above the present surface, considerably lower than elevations proposed by many models.

View abstract

View full article (Subscription required)