Greenland ice slip ‘n’ slides into ocean

[jpak]

http://www.futurity.org/earth-environment/greenland-ice-slip-n-slides-into-ocean/

U. COLORADO-BOULDER (US) — A new study reports that the Greenland Ice Sheet may be sliding into the ocean faster due to massive releases of meltwater from surface lakes.

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

“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,” says CIRES research associate William Colgan, who co-led the new study with 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,” Colgan says.

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[dipsydoodle]

1. We've had documentaries on the subject here in the UK

but without any mention of the "weight of water" causing the fissures. I have no concept of the head of water which would be necessary to crack an ice sheet with an average thickness of 2 Kms.

There are some videos of these events on Youtube. Quite dramatic when one of the lakes suddenly disappears down a seemingly bottomless chasm.

One here from 4 years ago :

[longship]

2. James Balog!!!

James Balog is a shutterbug who has seized the nettle of climate change in one specific area, continental ice melt.

See the TED talk ( search Ted.com for Balog) to see astonishing documentation of glacier melting. Also, and subsequent to his TED Talk, see Balog's recent Nova program, Extreme Ice. It is a compelling document to Earth's climate.

I love the scene where Balog unequivocally states that it is not safe for him to be perched on the edge of the precipice of ice he's leaning over without a safety harness. But, like a great scientist, he is lured to the edge of knowledge in spite of the dangers. Nature is the the final arbiter!

The photography, and the story, is wonderful. One of the best Nova programs ever.

[OnlinePoker]

3. They're wrong on this part

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.

An Olympic sized swimming pool is 50m X 25m X 2m or 2500 cubic meters. 1 million cubic meters would be 400
Olympic Swimming pools, not 4000.

[pscot]

4. The calculator is a lethal weapon..

[pscot]

5. Has anyone ever dumped a dye pak into one of those

to see where it comes out?