Mysterious South American glaciers grow as others shrink
June 23rd, 2009 - 1:39 pm ICT by ANI
Washington, June 23 (ANI): In times when most glaciers in the world are shrinking due to global warming, two mysterious South American glaciers are displaying strange behavior in the sense that they are growing.
“Most of the 50 massive glaciers draped over the spine of the Patagonian Andes are shrinking in response to a global warming,” said Andres Rivera, a glaciologist at the Center for Scientific Studies in Valdivia, Chile.
But, according to a report in National Geographic News, the Perito Moreno glacier in Argentina and Pio XI glacier in Chile are taking on ice, instead of shedding it.
“What is happening is not well understood,” Rivera said.
Theories center on the geography and topography of the glaciers; the depth and temperature of the waters where the glaciers end; and how quickly, or slowly, they react to changes in the climate.
Yet overall, “if you account for the gains and losses of all of Patagonia’s glaciers, they are (still) losing huge amounts of ice,” Rivera pointed out.
“One hypothesis for the 3-mile-wide (5 kilometer-wide) Perito Moreno’s advance is the glacier’s apparent insensitivity to changes in what glaciologists call the equilibrium line on glaciers,” Rivera said.
As a result, the amount of ice lost or gained is minimal.
It could also be that Perito Moreno simply hasn’t got all that much to lose.
Lago Argentino, the lake where Perito Moreno ends, is shallower than the bodies of water at the ends of most glaciers.
Most glaciers calve, or release ice, in deep water, but not Perito Moreno, where the calving rates are higher than on other Patagonian glaciers.
That means less of the glacier is in the melting zone below the equilibrium line.
As heavy snowfall above the equilibrium line pushes the glacier downhill, the glacier breaks up when it hits the lake, Rivera explained.
“Such impacts kept the glacier from growing longer when the climate was cooler, and thus more likely to expand,” he said.
As for the Pio XI glacier in Chile, some scientists have attempted to explain its advance as a glacial surge, a periodic and sudden expansion of a glacier that is little understood but is thought to be unrelated to external forces. (ANI)
- Huge chunk of Argentina's glacier collapses - Mar 05, 2012
- 65 percent Himalayan glaciers melting: Scientist - Jul 19, 2011
- Glaciers melting 100 times faster - Apr 04, 2011
- Glaciers 'melting 100 times faster than at any time in 350 yrs' - Apr 04, 2011
- Argentine glacier recedes due to global warming - Dec 14, 2010
- Alarm bells over Greenland ice melt - Oct 26, 2011
- Global warming taking giant bites out of underbellies of Greenland's glaciers - Feb 15, 2010
- Melting glaciers on Arctic islands play major role in rise of sea level - Apr 21, 2011
- Short-term weather extremes, not warming, driving Greenland ice sheet flow: Study - Dec 09, 2010
- Footloose glaciers cracking up - Jul 15, 2010
- Global wind-shift caused Earth's last ice age to end - Jun 26, 2010
- Global warming not the only cause behind Great Aletsch Glacier's illness - Jun 05, 2010
- Melting ice in Canadian Arctic bigger player in sea-level rise - Apr 22, 2011
- Himalayan glaciers' melting poses threat to not only Bhutan, but entire South Asia - Oct 23, 2009
- Chilean held for stealing ice from a glacier - Feb 01, 2012
Tags: bodies of water, calve, calving, deep water, equilibrium line, glaciologist, global warming, heavy snowfall, hypothesis, insensitivity, massive glaciers, national geographic news, patagonian andes, patagonian glaciers, perito moreno glacier, perito moreno glacier in argentina, pio xi, strange behavior, topography, valdivia chile