A robotic submarine, designed to slip beneath narrow boreholes in the thick Antarctic ice, will soon be giving scientists their first direct look at melting glaciers, which many consider to be ground zero for tracking the footprints of climate change.
Monitoring sea ice melt is a critical component of studies to assess impacts of global warming, but data collection so far has been mostly a remote affair with measurements taken from ice sheet surfaces.
A 28-foot-long, cigar-shaped submarine should change that, collecting information and retrieving samples from beneath the floating Ross Ice Shelf, a Texas-sized glacier in western Antarctica.
"What we're concerned about is where the warm ocean waters potentially penetrate beneath the ice shelf and hasten melting," said Northern Illinois University geologist Ross Powell, who unveiled the project at the American Geophysical Union conference in San Francisco this week.
Predicting the rise of sea levels has been difficult because scientists don't have the information to create accurate computer models. The sub-ice rover, nicknamed SIR, will observe melting right where seawater meets the glacier's base.
"It's designed to go to an area where no man has ever been before and probably will never get there ... we have to do this remotely," Powell said.
SIR is scheduled for a trial run in Lake Tahoe in March before being deployed to Antarctica for testing in late 2011 or early 2012. If all goes well, about a year later the submarine is slated to begin a series of missions, sliding down half-mile long, 30-inch wide ice boreholes and surfacing up others 12 miles away.
The submarine, which weighs about 2,200 pounds and collapses to 22 inches in diameter to fit through the holes, will remain tethered and powered to a control center on the surface throughout the surveys, which are expected to last up to about 10 days at a time.
SIR's suite of science gear includes five cameras, a robot arm to gather samples and a host of other instruments and sensors to track currents, sample water, measure distances and map the seafloor.
The submarine will also moonlight for biologists interested in microbial communities living beneath the ice, added geologist Reed Scherer, also with Northern Illinois University.
"Every time we go somewhere new, someone discovers new species," said Peter Girguis, associate professor of biology at Harvard University.
The sub will retrieve samples from the seabed sediment for laboratory analysis.
"We wanted as much science as we could for the effort," said Powell.