Scientists watch growing Antarctic crack but aren't alarmed

January 7, 2017 by Seth Borenstein
This Nov. 10, 2016 aerial photo released by NASA, shows a rift in the Antarctic Peninsula's Larsen C ice shelf. According to NASA, IceBridge scientists measured the Larsen C fracture to be about 70 miles long, more than 300 feet wide and about a third of a mile deep. (John Sonntag/NASA via AP)

Scientists are watching, but not alarmed by, a growing crack at the edge of a key floating ice shelf in Antarctica.

New images show the long-watched rift in the Larsen C grew 11 miles (18 kilometers) in the last few weeks. The crack is now about 60 miles long (97 kilometers) and about 300 feet wide (100 meters).

If it grows another dozen miles, a Delaware-sized iceberg could break off and float away.

University of Colorado scientist Ted Scambos said that could happen soon, likely in March, and would "cut deeper to the bone" of the ice shelf, changing its shape. Ice shelves—sheets of floating ice—wrap around three-quarters of the South Pole's coastline. They provide protection and support for inland glaciers.

Scambos, who is about to travel to Antarctica for research, and other scientists said they don't see other key signs that this growing crack would result in a catastrophic collapse of the entire shelf. A chunk of ice will break off, "But it's not going to lead to a runaway disintegration," he said Friday.

That's what happened suddenly in 2002 to the smaller Larsen B shelf, allowing inland glaciers to shrink rapidly. NASA glaciologist Jay Zwally said there's no rapid melting with ponds of water on top of the ice this time.

This Nov. 10, 2016 aerial photo released by NASA, shows a rift in the Antarctic Peninsula's Larsen C ice shelf. According to NASA, IceBridge scientists measured the Larsen C fracture to be about 70 miles long, more than 300 feet wide and about a third of a mile deep. (John Sonntag/NASA via AP)

"By itself this calving is not a cause for alarm," Zwally said.

Large icebergs do periodically break off from Antarctica naturally, Zwally said. "But the ice shelf has been thinning as other ice shelves have been thinning in the Antarctic peninsula," he said.

There's no evidence linking this crack to climate change, yet it fits the overall warming picture, said Adrian Luckman, a researcher at Swansea University in England, which has been monitoring the crack.

Explore further: Giant iceberg set to calve from Larsen C ice shelf

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antigoracle
1 / 5 (6) Jan 08, 2017
There's no evidence linking this crack to climate change, yet it fits the overall warming picture

So, it is NOT Globull warming, but let's say so anyway. Never mind that the entire area is right above extensive geothermal activity and this is not happening elsewhere.
novaman
Jan 08, 2017
This comment has been removed by a moderator.
Benni
1 / 5 (9) Jan 08, 2017
There's no evidence linking this crack to climate change, yet it fits the overall warming picture

So, it is NOT Globull warming, but let's say so anyway. Never mind that the entire area is right above extensive geothermal activity and this is not happening elsewhere.
..........it could be that the dishonest media has finally figured out that the narrative of Melting Ice scaremongery has worn out & run it's course.

Puzzling though, why didn't the report make note that the "crack" formed at a location of known thermal activity? But, they did make it a point to insert this least important brief blip: "There's no evidence linking this crack to climate change, yet it fits the overall warming picture, said Adrian Luckman."...........talk about the Dishonest Media saying one but meaning another, come to a fork in the road & they take the fork.
HeloMenelo
4.3 / 5 (6) Jan 08, 2017
There's no evidence linking this crack to climate change, yet it fits the overall warming picture

So, it is NOT Globull warming, but let's say so anyway. Never mind that the entire area is right above extensive geothermal activity and this is not happening elsewhere.


Wrong again, it points to climate change, not the geothermal activity, there is plenty of evidence for climate change, however only hot air every time you lay your fingers on a keyboard, those aren't pretty buttons, they are meant to construct meaningful sentences, (go ask your askdaddy sock to ask his daddy ;)
Benni
1 / 5 (6) Jan 08, 2017
There's no evidence linking this crack to climate change, yet it fits the overall warming picture

So, it is NOT Globull warming, but let's say so anyway. Never mind that the entire area is right above extensive geothermal activity and this is not happening elsewhere.


Wrong again, it points to climate change, not the geothermal activity, there is plenty of evidence for climate change, however only hot air every time you lay your fingers on a keyboard, those aren't pretty buttons, they are meant to construct meaningful sentences, (go ask your askdaddy sock to ask his daddy


Hey, if for you life is so boring & you have so much time in your hands, why don't you put all that time you spend on the keyboard to some really productive use. Come to my place, meet me at the foot of my turnaround where I'll provide you with a shovel to get you started on the two feet of snow covering it. No dice huh?

HeloMenelo
5 / 5 (4) Jan 08, 2017
Sorry gotta turn down that offer ;) My life is more than perfect with all my science friends here thank you, and am more than happy to defend the earth against trolls here, on the other hand we can see you've been here for millennia, an old rust bucket ? part of the furniture eh ? Got a spade, got plenty of gardening work for ya, lots of garbage you can take out too ? :)
humy
5 / 5 (6) Jan 08, 2017
whether a particular crack in the ice can be attributed to global warming is irrelevant to the claim made by some laypeople that there is no global warming; there is overwhelming empirical evidence of global warming that has nothing to do with a single crack in the ice and science still proves what science proves irrespective of some science-ignorant layperson opinion to the contrary.
humy
5 / 5 (1) Jan 09, 2017
...Never mind that the entire area is right above extensive geothermal activity and this is not happening elsewhere.


I have just researched this and this is simply not true; there is NO "extensive geothermal activity" around or under the Larsen Ice Shelf where the crack formed.
There is much geothermal activity on the other side of Antarctica which is obviously way too far away to explain the current crack.
So your assertion is simply totally wrong.
Can you give a link that shows "extensive geothermal activity" under the Larsen Ice Shelf region?
humy
5 / 5 (2) Jan 09, 2017
...Never mind that the entire area is right above extensive geothermal activity and this is not happening elsewhere.


antigoracle

Not only is there NO such "extensive geothermal activity" under that shelf (see my last post), but even if there was, it cannot easily explain the huge crack. This is because any such "extensive geothermal activity" would be on the sea floor UNDER WATER under the FLOATING shelf and thus the worst of the heat from any such geothermal activity will not be directly applied to the ice above but highly dispersed in the water well before it gets in contact with the ice and mere indirect gentle heating from highly dispersed slightly warmer water from below is unlikely to exert the kind of stupendously large forces to create such a vast deep crack
Why wouldn't such gentle heating from below be far more likely to melt a hole in the ice rather and make a huge crack?.

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