Massive Subsurface Lakes Calls Stability Of Antarctic Ice Sheets Into Question - Independent

[hatrack]

The long-term stability of the massive ice sheets of Antarctica, which have the potential to raise sea levels by hundreds of metres, has been called into question with the discovery of fast-moving rivers of water sliding beneath their base. Scientists analysing satellite data were astonished to discover the size of the vast lakes and river systems flowing beneath the Antarctic ice sheets, which may lubricate the movement of these glaciers as they flow into the surrounding sea.

The discovery raises fresh questions about the speed at which sea levels might rise in a warmer world due to the rate at which parts of the ice sheets slide from the land into the ocean, scientists said at the American Association for the Advancement of Science in San Francisco. "We've found that there are substantial subglacial lakes under ice that's moving a couple of metres per day. It's really ripping along. It's the fast-moving ice that determines how the ice sheet responds to climate change on a short timescale," said Robert Bindschadler, a Nasa scientist at the Goddard Space Flight Centre in Maryland, one of the study's co-authors.

"We aren't yet able to predict what these ice streams are going to do. We're still learning about the controlling processes. Water is critical, because it's essentially the grease on the wheel. But we don't know the details yet," Dr Bindschadler said. "Until now, we've had just a few glimpses into what's going on down there. This is the most complete picture to date about what's going on," he said.

The findings, to be published in the journal Science, came from satellite surveillance of the surface elevation of the ice sheets, which found that they rise or lower depending on the amount of water flowing between the base of the ice sheet and the rock beneath.

EDIT

http://news.independent.co.uk/environment/article2274481.ece

[GliderGuider]

1. It looks like ice is a lot more dynamic than we'd assumed

Between this and the discovery of the dynamic effects of water flowing vertically through fissures in the Greenland glaciers, I suspect the ice sheets have a lot of secrets yet to give up. The problem this raises is that the public wants accurate predictions right now thank you very much, but it could be decades before we have any confidence in our understanding of the mechanisms at work. In the meantime, Mother Nature is going to teach us by demonstration, as she usually does.

[kestrel91316]

2. Hypothetically speaking, of course, just HOW MUCH would sea

levels rise if ALL the Antarctic ice melted???

I'm not talking about the West Antarctic ice sheet plus Greenland. I'm talking about the WHOLE SHEBANG.

[GliderGuider]

3. 220 feet...

From our Wikipedic friends:

The sea level could rise above its current level if more polar ice melts. However, compared to the heights of the ice ages, today there are very few continental ice sheets remaining to be melted. It is estimated that Antarctica, if fully melted, would contribute more than 60 metres of sea level rise, and Greenland would contribute more than 7 metres. Small glaciers and ice caps might contribute about 0.5 metres.

[kestrel91316]

4. Well, I'm more than safe at 800+ feet above sea level. I think I'll

buy me a HUMMER!!!!!!!!

[hogwyld]

11. Just make sure it's good 'ol H1. Don't wimp out with the H2 or H3

Make sure to get your greenhouse gas emissions worth.

[happyslug]

10. But the East Antarctic Ice Sheet is the most Stable

In fact global warming is expected to INCREASE do to global warming, do to the greater ability of Hotter air to hold moisture. When this hotter air goes over the East Antarctic Ice Sheet dropping MORE snow over that Ice Sheet. Remember the Antarctic is the HIGHEST continent, being HIGHER on Average than any other continent as while as the ONLY Continent within the Arctic or Antarctic Circles.

Thus the main Concern is the much smaller Greenland and West Antarctic Ice Sheets. These are NOT as high or as large and affected by the world's Ocean (The West Antarctic Ice Sheet is grounded BELOW sea level, while the Greenland Ice Sheet is near the Gulf Stream).

[hogwyld]

12. Yippee!

We can all be like Kevin Costner, and grow gills. Webbed hands and feet would be pretty cool too. :sarcasm:

[rman]

7. Part of Antarctica and Greenland ice is already melting

each is good for 20ft.

see "An Inconvenient Truth"
http://video.google.com/videoplay?docid=2078944470709189270 (trailer)

[XemaSab]

5. One word:

:popcorn:

[rman]

8. I think it's not going to be entertaining.

[Gregorian]

6. People underestimate the amount of human activity on this planet.

I always had to know how everything worked. That's why I ended up a machinist and a mechanical engineer. At the age of one I had to be sent to the emergency room after electrocuting myself. I had taken all of my toys apart and even gashed myself. By two, I had driven my parents Oldsmobile.

I think people don't really see the full extent of things. Just look at a toilet. It takes a hell of a lot of energy to make one of those. Every meal. Every package it comes in. And it's compounded through time. Every trip to the market in 1948. Every shower. Every toilet flush requires a pump to run. These things all produced carbon dioxide emissions. Wars are especially dramatic producers. Every building. Every contractor who goes to the job to build them. Every architect to goes to work to design them. I could sit here and type all night long on the different things. Basically, everything has a carbon dioxide emission associated with it.

I think the goal is to get the people of the world to see things as people like myself see them. To see the full history of processes involved in creating what we consume. We're an ignorant society, and world, in that respect. And it's no accident.

What worries me the most is the addiction. Once we are used to warm showers, we are not likely to change. I just moved from the country to Mendocino. Well, I guess that is still country. But it's not remote. Being remote, I didn't see cars for many years. After witnessing a stream of cars I simply cannot fathom, for living on a small country road, I decided to get on my bike and see how many people lived beyond me. There are sixty houses beyond me on this dead end road. And the cars come about one every thirty seconds! I absolutely cannot believe it. What this means is that people are making a multiplicity of trips every single day. Work, kids to school, kids back from school, market, and any number of things. This is about ten trips per house per day. And I get in my vehicle once a week. What is wrong with Americans? Is it boredom? Do we jump in our vehicles because we don't consolidate trips responsibly? All I can say is, with what I see here, I do not expect positive change. I suspect we'd rather die before we change. I hope I'm wrong. Thanks to global warming we might actually have a better society soon. The car distances people and communities. And it distances us from our very environment. I have waited for this day for many years. It won't be easy. But it'll be much better.

[glitch]

9. I know what you mean about the cars and multiplicity of trips.

I live in Seattle and walk for everything except for things too heavy to carry. But I recently visited my parents in the "country" and was astounded at how often they took the cars out (oh yes, they each had their own separate errands to run). No real planning to do several things on one trip even. It is the way of life not just in the suburbs but in the exurbs, although they call it "country".
And these are people in their 70s, retired. I can only imagine the trips run by commuting soccer parents.