Greenland ice sheet may be sliding away due to surface lake melt

   Apr 17, 12:57 pm

Washington, April 17 (ANI): Greenland ice sheet may be sliding faster into the ocean because of massive releases of meltwater from surface lakes , a new study suggests.

Such lake drainages may affect sea-level rise, with implications for coastal communities, according to researchers at the University of Colorado Boulder-based Cooperative Institute for Research in Environmental Sciences.

"This is the first evidence that Greenland's 'supraglacial' lakes have responded to recent increases in surface meltwater production by draining more frequently, as opposed to growing in size," said CIRES research associate William Colgan, who co-led the new study with CU-Boulder computer science doctoral student Yu-Li Liang.

During summer, meltwater pools into lakes on the ice sheet's surface. When the water pressure gets high enough, the ice fractures beneath the lake, forming a vertical drainpipe, and "a huge burst of water quickly pulses through to the bed of the ice sheet," explained Colgan.

The researchers used satellite images along with innovative feature-recognition software to monitor nearly 1,000 lakes on a Connecticut-sized portion of the ice sheet over a 10-year period.

They discovered that as the climate warms, such catastrophic lake drainages are increasing in frequency. Catastrophic lake drainages were 3.5 times more likely to occur during the warmest years than the coldest years.

During a typical catastrophic lake drainage, about 1 million cubic meters of meltwater-which is equivalent to the volume of about 4,000 Olympic swimming pools-funnels to the ice sheet's underside within a day or two.

Once the water reaches the ice sheet's belly that abuts underlying rock, it may turn the ice-bed surface into a Slip N Slide, lubricating the ice sheet's glide into the ocean. This would accelerate the sea-level rise associated with climate change.

Alternatively, however, the lake drainages may carve out sub-glacial "sewers" to efficiently route water to the ocean.

"This would drain the ice sheet's water, making less water available for ice-sheet sliding," Colgan said.

That would slow the ice sheet's migration into the ocean and decelerate sea-level rise.

"Lake drainages are a wild card in terms of whether they enhance or decrease the ice sheet's slide," Colgan said.

Finding out which scenario is correct is a pressing question for climate models and for communities preparing for sea-level change, he said.

The study has been published online by the journal Remote Sensing of the Environment. (ANI)

Asteroid that made dinosaurs extinct almost wiped off mammals too Dec 18, 1:17 pm
Washington, Dec 18 (ANI): A new study has shed light on an asteroid that wiped out dinosaurs may have wiped out mammals as well.
Full Story
Science community happy over successful launch of GSLV Mark-III Dec 18, 1:14 pm
New Delhi, Dec. 18 (ANI): Senior scientist and SPACE India director C B Devgun on Thursday expressed happiness over the successful launch of Geosynchronous Satellite Launch Vehicle (GSLV) Mark-III, adding that this was the first test done without the cryogenic engine and that the new module CREW that has been crafted to ensure the safe arrival of astronauts back to earth, had been tested successfully.
Full Story
Substance from broccoli can help ward off premature ageing Dec 18, 1:14 pm
Washington, Dec 18 (ANI): A team of scientists has revealed that Hutchinson-Gilford Progeria Syndrome (HGPS) related defects can be reduced with the help of a substance found in broccoli.
Full Story
Longer we take to decide, the less accurate and confident we get Dec 18, 12:28 pm
Washington, Dec 18 (ANI): A team of neuroscientists has found that the longer people take to decide, the less accurate and confident they are.
Full Story
Comments

LATEST STORIES
TOP VIDEO STORIES
PHOTO GALLERY