Skip to content

False Alarm: Antarctic Ice Shelves Not Melting At All, New Field Data Show

Twenty-year-old models which have suggested serious ice loss in the eastern Antarctic have been compared with reality for the first time – and found to be wrong, so much so that it now appears that no ice is being lost at all.

“Previous ocean models … have predicted temperatures and melt rates that are too high, suggesting a significant mass loss in this region that is actually not taking place,” says Tore Hattermann of the Norwegian Polar Institute, member of a team which has obtained two years’ worth of direct measurements below the massive Fimbul Ice Shelf in eastern Antarctica – the first ever to be taken.

According to a statement from the American Geophysical Union, announcing the new research:

It turns out that past studies, which were based on computer models without any direct data for comparison or guidance, overestimate the water temperatures and extent of melting beneath the Fimbul Ice Shelf. This has led to the misconception, Hattermann said, that the ice shelf is losing mass at a faster rate than it is gaining mass, leading to an overall loss of mass.

The team’s results show that water temperatures are far lower than computer models predicted …

Hatterman and his colleagues, using 12 tons of hot-water drilling equipment, bored three holes more than 200m deep through the Fimbul Shelf, which spans an area roughly twice the size of New Jersey. The location of each hole was cunningly chosen so that the various pathways by which water moves beneath the ice shelf could be observed, and instruments were lowered down.

The boffins also supplemented their data craftily by harvesting info from a biology project, the Marine Mammal Exploration of the Oceans Pole to Pole (MEOP) effort, which had seen sensor packages attached to elephant seals.

“Nobody was expecting that the MEOP seals from Bouvetoya would swim straight to the Antarctic and stay along the Fimbul Ice Shelf for the entire winter,” Hattermann says. “But this behaviour certainly provided an impressive and unique data set.”

Full story

 

see also this 2009 Guardian Scare: World’s largest ice sheet melting faster than expected

East Antarctic sheet shedding 57bn tonnes of ice a year and contributing to sea level rises, according to Nasa aerial survey

Polar landscape of Holtedehl Bay, Antarctica

Scientists believe that Antarctica could lose more ice than Greenland within a few years.

 

The world’s largest ice sheet has started to melt along its coastal fringes, raising fears that global sea levels will rise faster than scientists expected.

The East Antarctic ice sheet, which makes up three-quarters of the continent’s 14,000 sq km, is losing around 57bn tonnes of ice a year into surrounding waters, according to a satellite survey of the region.

Scientists had thought the ice sheet was reasonably stable, but measurements taken from Nasa’s gravity recovery and climate experiment (Grace) show that it started to lose ice steadily from 2006.

The measurements suggest the polar continent could soon contribute more to global sea level rises than Greenland, which is shedding more than 250bn tonnes of ice a year, adding 0.7mm to annual sea level rises.

Satellite data from the whole of Antarctica show the region is now losing around 190bn tonnes of ice a year. Uncertainties in the measurements mean the true ice loss could be between 113bn and 267bn tonnes.

Full story