Newly Discovered Meltwater Streams Flow Beneath the Antarctic Ice Sheet

The Telegraph reports that previously undetected streams of meltwater have been observed beneath the Antarctic ice sheet. "The streams of water, some of which are 250m in height and stretch for hundreds of kilometres, could be destabilising parts of the Antarctic ice shelf immediately around them and speeding up melting, researchers said. However, they added that it remains unclear how the localised effects of the channels will impact on the future of the floating ice sheet as a whole. The British researchers used satellite images and radar data to measure variations in the height of the Filchner-Ronne Ice Shelf in West Antarctica, which reveal how thick the ice is." The paper itself is paywalled, but the abstract is available online.

Comments

The (actual) Surf

[MrKaos]

I know, the correlation/causation comment will come up, but you would never know the water temperature unless you got in the water and feel it for yourself over 2-3 decades of actually being in the water and knowing when to get in. I wouldn't call 250metres a stream, but other noticable thing is the way the weather has changed from a smooth transition to summer where it gradually got hotter to bursts of weather change where you will suddenly get days of really warm weather in winter and then back to cold and visa versa in summer.

I regularly goes for a swim or a surf on the east coast of Australia and for the last decade years the water has been really cold during seasons where I used to notice it was pretty warm. It has altered my whole habit of surfing. I used to go into the water around September and now it's late October. I love the waves but the goolie shock is just to severe. My mates would say the same thing and often the comment 'at least we know where the ice caps are melting to' would come up.

Re:Ummmm

[JWSmythe]

Well, if it's increasing in surface area, but decreasing in mass, that would be a problem.

I think the concern they're trying to address is the same as one of the arctic ice concerns.

http://en.wikipedia.org/wiki/Outburst_flood

About 8,300 to 7,700 years ago, the melting ice dam over Hudson Bay's southernmost extension narrowed to the point where pressure and its buoyancy lifted it free, and the ice-dam failed catastrophically. Lake Ojibway's beach terraces show that it was 250 metres (820 ft) above sea level. The volume of Lake Ojibway is commonly estimated to have been about 163,000 cubic kilometres, more than enough water to cover a flattened-out Antarctica with a sheet of water 10 metres (33 ft) deep. That volume was added to the world's oceans in a matter of months.

I'm not saying that it's possible, or even probable. It's just an example of what destabilized polar ice can do. There's a whole lot of mass there.

Remember, the 2004 Indian Ocean Tsunami was caused by a 1,000 mile long rift shifting by 50 feet over a few minutes. If a sufficiently sized chunk (or chunks) of ice moved enough, there could be catastrophic effects for boating and coastal areas.

The long-term sea-level rise will be slow, and civilization will change around it. The short term effects of such events can be fast and catastrophic.