Posts tagged ice

NASA has been taking a creatively close look inside a crack in the Antarctic ice shelf that threatens to break off and create a city-sized iceberg.

Using data collected late last year by scientists, NASA have created an animated virtual ride through a giant canyon of Antarctic ice in Pine Island Glacier in western Antarctica. And while sea ice is expanding around much of the ice cap, Dr Pat Langhorne from Otago University says this is an area scientists are focused on.

“It’s a region that’s well known to be warming, there is a smaller ice extent in that area than there has been since satellites began,” says Dr Langhorne. The crack’s about 32 kilometres long and 50 metres deep, down to the water line of the Amundsen Sea.

(Source: futurenow321)

Data collected from a NASA ice-watching satellite reveal that the vast ice shelves extending from the shores of  western Antarctica are being eaten away from underneath by ocean currents, which have been growing warmer even faster than the air above.

The animation above shows the circulation of ocean currents around the western Antarctic ice shelves. The shelf thickness is indicated by the color; red is thicker (greater than 550 meters), while blue is thinner (less than 200 meters).

Launched in January 2003, NASA’s ICESat (Ice, Cloud and land Elevation Satellite) studied the changing mass and thickness of Antarctica’s ice from its location in polar orbit. An international research team used over 4.5 million surface height measurements collected by ICESat’s GLAS (Geoscience Laser Altimeter System) instrument from Oct. 2005 to 2008. They concluded that 20 of the 54 shelves studied nearly half were losing thickness from underneath.

(Source: futurenow321)

The researchers used a satellite laser to measure the thinning occurring on ice shelves - the floating tongues of ice that jut out from the land.

The team’s analysis found the shelves’ shrinkage could not be attributed simply to warmer air temperatures.

Rather, it is warm water getting under the floating ice to melt it from below.

This is leading to a weakening of the shelves, permitting more and more ice to drain from the continent’s interior through tributary glaciers.

Previous studies have already indicated that warmer waters are being driven towards the continent by stronger westerly winds in the Southern Ocean.

The researchers say the new understanding has major implications for their ability to reliably project future sea-level rises as a result of Antarctic ice loss.

(Source: futurenow321)

UK, US and Australian scientists used satellite technology to trace and count the iconic birds, finding them to number almost 600,000.

Their census technique relies in the first instance on locating individual colonies, which is done by looking for big brown patches of guano (penguin poo) on the white ice.

High resolution imagery is then used to work out the number of birds present.

It is expected that the satellite mapping approach will provide the means to monitor the long-term health of the emperor population.

(Source: futurenow321)