An international team of researchers funded by NASA and the National Science Foundation (NSF) will travel next month to one of Antarctica's most active, remote and harsh spots to determine how changes in the waters circulating under an active ice sheet are causing a glacier to accelerate and drain into the sea, the US space agency announced Wednesday.

The science expedition will be the most extensive ever deployed to Pine Island Glacier. It is the area of the ice-covered continent that concerns scientists most because of its potential to cause a rapid rise in sea level. Satellite measurements have shown this area is losing ice and surrounding glaciers are thinning, raising the possibility the ice could flow rapidly out to sea.

The multidisciplinary group of 13 scientists, led by Robert Bindschadler, emeritus glaciologist of NASA's Goddard Space Flight Center, will depart from the McMurdo Station in Antarctica in mid- December and spend six weeks on the ice shelf. During their stay, they will use a combination of traditional tools and sophisticated new oceanographic instruments to measure the shape of the cavity underneath the ice shelf and determine how streams of warm ocean water enter it, move toward the very bottom of the glacier and melt its underbelly.

"The project aims to determine the underlying causes behind why Pine Island Glacier has begun to flow more rapidly and discharge more ice into the ocean," said Scott Borg, director of NSF's Division of Antarctic Sciences, the group that coordinates all US research in Antarctica. "This could have a significant impact on global sea-level rise over the coming century."