A quick rebound of Antarctic crust promotes ice-sheet stability

June 21, 2018

The unexpectedly rapid rebound of the Amundsen Sea Embayment (ASE) may help stabilize the West Antarctic Ice Sheet against catastrophic collapse, says a new study offering a rare silver-lining in glacier research. The marine portion of the WAIS accounts for a quarter of the world's ice contribution to global sea level rise and is currently vulnerable to catastrophic collapse. As glaciers and ice sheets ebb and flow, they deform the Earth's crust. When loaded with icy weight, the crust is depressed, and as ice retreats, the surface rebounds like a spring, uplifting at a rate largely determined by the viscosity of the upper mantle underlying the region. This slow process is called glacial isostatic adjustment (GIA) and was thought to occur over a 10,000 year-timescale. However, Barletta et al. now show that in fact, the ASE is undergoing one the fastest glacial isostatic uplift rates ever recorded - a 41 millimeters annually. The authors used GPS data that measures the deformation rates of the ASE to model the viscosity of the mantle below the region and found it to be much lower than expected (approximately 4x1018 pascal seconds). The new data suggests that GIA can happen on a timescale measured not in thousands or tens of thousands of years, but rather, on the far faster scale of centuries or decades. Based on their estimates, as the WAIS retreats, the rapid uplift of the ASE has the potential to produce a deformation that is both large and early enough in the deglaciation to prevent the complete collapse of the ice sheet, even under strong climate forcing. The rapid uplift may even be able to delay collapse events outlined in more extreme scenarios, the authors say.
-end-


American Association for the Advancement of Science

Related Ice Sheet Articles from Brightsurf:

Greenland ice sheet shows losses in 2019
The Greenland Ice Sheet recorded a new record loss of mass in 2019.

Warming Greenland ice sheet passes point of no return
Nearly 40 years of satellite data from Greenland shows that glaciers on the island have shrunk so much that even if global warming were to stop today, the ice sheet would continue shrinking.

Greenland ice sheet meltwater can flow in winter, too
Liquid meltwater can sometimes flow deep below the Greenland Ice Sheet in winter, not just in the summer, according to CIRES-led work published in the AGU journal Geophysical Research Letters today.

Ice sheet melting: Estimates still uncertain, experts warn
Estimates used by climate scientists to predict the rate at which the world's ice sheets will melt are still uncertain despite advancements in technology, new research shows.

Thousands of meltwater lakes mapped on the east Antarctic ice sheet
The number of meltwater lakes on the surface of the East Antarctic Ice Sheet is more significant than previously thought, according to new research.

Researchers discover ice is sliding toward edges off Greenland Ice Sheet
They found that ice slides over the bedrock much more than previous theories predicted of how ice on the Greenland Ice Sheet moves.

A clearer picture of global ice sheet mass
Fluctuations in the masses of the world's largest ice sheets carry important consequences for future sea level rise, but understanding the complicated interplay of atmospheric conditions, snowfall input and melting processes has never been easy to measure due to the sheer size and remoteness inherent to glacial landscapes.

Researchers discover more than 50 lakes beneath the Greenland Ice Sheet
Researchers have discovered 56 previously uncharted subglacial lakes beneath the Greenland Ice Sheet bringing the total known number of lakes to 60.

Ice-sheet variability during the last ice age from the perspective of marine sediment
By using marine sediment cores from Northwestern Australia, a Japanese team led by National Institute of Polar Research (NIPR) and the University of Tokyo revealed that the global ice sheet during the last ice age had changed in shorter time scale than previously thought.

Novel hypothesis goes underground to predict future of Greenland ice sheet
The Greenland ice sheet melted a little more easily in the past than it does today because of geological changes, and most of Greenland's ice can be saved from melting if warming is controlled, says a team of Penn State researchers.

Read More: Ice Sheet News and Ice Sheet Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.