Sediment wedges not stabilizing West Antarctic Ice Sheet

September 3, 2013

The stability of the West Antarctic Ice Sheet is uncertain as climate changes. An ice sheet such as the West Antarctic Ice Sheet that is grounded well below sea level on a bed that slopes toward the interior of the sheet is believed to be unstable: when the grounding zone, where the grounded sheet transitions into floating ice, retreats inland, it can potentially lead to massive amounts of ice becoming ungrounded and floating into the ocean, unless something such as a wedge of sediment stabilizes the ice sheet.

It has been proposed that such a sediment wedge stabilizes the grounding zone of the Whillans Ice Stream, one of the large ice streams flowing from the West Antarctic Ice Sheet. However, most understanding of ice sheet stability at grounding zones comes from models and remote observation rather than field-based observations.

Horgan et al. looked at at the current grounding zone of Whillans Ice Stream using seismic and kinematic GPS methods. They find that sedimentary deposits are present, but these sediments are not forming the wedge-shaped deposits thought to stabilize the grounding zone. They suggest that some other mechanism may be creating stability.

Explore further: Research reveals ice sheet stability in West Antarctica under threat

More information: Horgan, H. et al. Sediment deposition at the modern grounding zone of Whillans Ice Stream, West Antarctica, Geophysical Research Letters. DOI: 10.1002/grl.50712 , 2013 http://onlinelibrary.wiley.com/doi/10.1002/grl.50712/abstract

Related Stories

Ancient ice melt unearthed in Antarctic mud

July 21, 2013

Global warming five million years ago may have caused parts of Antarctica's large ice sheets to melt and sea levels to rise by approximately 20 metres, scientists report today in the journal Nature Geoscience.

Search for ice sheet 'tipping point'

January 13, 2010

(PhysOrg.com) -- A new study examines how ice sheets, such as the West Antarctic Ice Sheet, could become unstable as the world warms.

Recommended for you

The birth and death of a tectonic plate

May 24, 2017

Several hundred miles off the Pacific Northwest coast, a small tectonic plate called the Juan de Fuca is slowly sliding under the North American continent. This subduction has created a collision zone with the potential to ...

Sub-zero waters a barrier to oil spill recovery

May 24, 2017

Sub-zero temperatures in the deep waters of the North Atlantic would significantly hamper the ability of oil-eating bacteria to help the ocean recover from a major oil spill, according to new research.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.