AGU Fall Meeting kicks off

 
Currently the amount of this “post-glacial rebound” is a key uncertainty in ice loss measurements, potentially reaching 100%. Scientists must account for it in their satellite-borne laser or radar altimetry measurements of the height of the ice surface, while exploiting gravity data from the GRACE (gravity recovery and climate experiment) satellite also requires knowledge of what’s happening in the bedrock below.

POLENET will help by providing data from the interior of West Antarctica - to date such measurements have mainly been concentrated around the perimeter of Antarctica, at permanent research bases. The GPS measurements will show how much the Earth’s crust is rising or falling while the seismic measurements will elucidate bedrock properties such as stiffness, which could help predict how much the rock will rise in the future.

“We’re pinning down both parts of this problem, which will improve the correction made to the satellite data, which will in turn improve what we know about whether we’re gaining or losing ice,” said Wilson.

Until now scientists mainly relied on computer models of post-glacial rebound.

“When you compare how fast the earth is rising, and where, to the models of where ice is being lost and how much is lost - they don’t match,” explained Wilson, speaking about earlier data taken in the area. “There are places where the models predict no crustal uplift, where we see several millimetres of uplift per year. We even have evidence of other places sinking, which is not predicted by any of the models.”

Installation of the sensors is due to be complete in 2010 and they’ll record data into 2012, technical glitches and harsh weather conditions permitting. Wilson is optimistic about other results that could come up from taking measurements in an area that’s never been looked at before. “I expect there to be an element of serendipity,” she said.