MUSIC: "Our World" theme
Straight ahead on "Our World" ... an ice shelf at the bottom of the world hangs by a thread... one of Saturn's moons has the ingredients for life... and flexible computer chips give surgeons a revolutionary new tool...
ROGERS: "We're putting electronics and sensors onto latex gloves so that the tips of the fingers in the glove provide a sensing capability for measuring blood oxygen content, blood pH, temperature, and so on."
Those stories, concentrating the power of the sun, and more. I'm Faith Lapidus, sitting in this week for Art Chimes. Welcome to VOA's science and technology magazine, "Our World."
Last week, we talked about the thinning of the Arctic icecap. This week, we turn our attention to the bottom of the earth ? the frigid expanse of Antarctica... where the ice is not thinning so much as disintegrating. Satellite images in recent weeks show that a large chunk of an Antarctic ice shelf has collapsed into the sea. As Rosanne Skirble reports, it is a sign of rapid climate change in a region that has experienced the greatest temperature increases on earth.
SKIRBLE: The Wilkins Ice Shelf is a large and thick plate of ice on the southwest Antarctic Peninsula. It is one of a string of ice shelves that has collapsed in the region over the last thirty years.
Ted Scambos is a glaciologist with the National Snow and Ice Data Center at the University of Colorado, Boulder. He says there was a curious pattern in the Wilkins collapse.
SCAMBOS: "The first iceberg that broke off was perfectly normal, but behind it this area began to slice off long chunks, sort of like long slices of bread basically off of a loaf, so tall and narrow that they actually topple over into the water and this is really unusual."
SKIRBLE: Scambos says this indicates that the ice shelf is in retreat. He says the shelf ? which floats on the ocean but is attached to land ? could break up entirely within a few years because of warming in the Antarctic Peninsula.
SCAMBOS: "That pattern is pretty clearly related to global warming and the effects that is having in the Antarctic air circulation pattern."
SKIRBLE: The collapse of some 400 square kilometers from the 14,000 square kilometer ice sheet won't have any immediate impact. But, Scambos says, understanding the process is key to being able to predict how sea level will change in the future.
SCAMBOS: "These ice shelves that fringe Antarctica actually act to hold back some of the ice that is on the continent and slow down glaciers that are flowing into the ocean. There is a balance of forces between ice wanting to flow off of this large mound of ice that is Antarctica and these ice plates that are fringing it are obstructing it and therefore resisting the flow."
SKIRBLE: With Antarctic summer coming to a close, Scambos doesn't expect that Wilkins will collapse any further this season. Nonetheless, scientists will continue to monitor the threatened ice shelf.
SCAMBOS: "The point is that we're seeing this pattern march southward, and we want to try to turn around the effects of greenhouse gases over the next two decades before we do have to worry about significant amounts of sea level rise from both Greenland and Antarctica."
SKIRBLE: The National Snow and Ice Data Center studies both polar regions. Scambos says while the arctic is showing more effects from global warming, the potential for sea level rise from Antarctic melts is far greater. I'm Rosanne Skirble.
On Wednesday, two weeks after NASA's Cassini space probe flew past one of Saturn's moons, Enceladus, skimming just 50 kilometers above the surface, scientists released their preliminary findings, including their view on whether Enceladus might harbor some form of life. They also discussed the composition of an icy plume of water vapor spewing from the surface.
Hunter Waite of the Southwest Research Institute in Texas is the principal investigator for the Ion and Neutral Mass Spectrometer, one of Cassini's scientific instruments. He described the plume that the spacecraft passed through.
HUNTER: "The line I used earlier was that it's carbonated water with essence of natural gas. Water vapor was the major constitutent. There was methane present. There was carbon dioxide. There was carbon monoxide. There were simple organics and there were more complex organics. So those are the constituents we saw."
Of course, while water and organic materials are necessary for life as we know it, their presence doesn't necessarily mean there is life.