Report

Rapid Thinning of Pine Island Glacier in the Early Holocene

Science  28 Feb 2014:
Vol. 343, Issue 6174, pp. 999-1001
DOI: 10.1126/science.1247385

You are currently viewing the abstract.

View Full Text
As a service to the community, AAAS/Science has made this article free with registration.

Once in a While

Many regions at the edge of the Antarctic Ice Sheet have rapidly increased the rates at which they are sliding into the sea and thinning, raising concerns that global warming might cause the sudden collapse of some sections. Johnson et al. (p. 999, published online 20 February) present data from Pine Island Glacier, which has been thinning and retreating rapidly over the past two decades. The glacier experienced another rapid thinning around 8000 years ago, which occurred about as quickly as is happening now, and which lasted for 25 to 100 years.

Abstract

Pine Island Glacier, a major outlet of the West Antarctic Ice Sheet, has been undergoing rapid thinning and retreat for the past two decades. We demonstrate, using glacial-geological and geochronological data, that Pine Island Glacier (PIG) also experienced rapid thinning during the early Holocene, around 8000 years ago. Cosmogenic 10Be concentrations in glacially transported rocks show that this thinning was sustained for decades to centuries at an average rate of more than 100 centimeters per year, which is comparable with contemporary thinning rates. The most likely mechanism was a reduction in ice shelf buttressing. Our findings reveal that PIG has experienced rapid thinning at least once in the past and that, once set in motion, rapid ice sheet changes in this region can persist for centuries.

View Full Text