Posted on 03/06/2011 9:19:47 AM PST by smokingfrog
*** Ice sheet structure far different than thought — complicating rising-sea scenarios ***
Knowing how the massive ice sheets atop Antarctica and Greenland work is key to predicting how global warming could raise sea levels and flood coastal cities. But a new study upends what scientists thought they knew. It turns out it’s not just ancient snow that makes up the ice sheets, but water deep under the sheets also thaws and refreezes over time.
To put it in non-scientific terms, lead scientist Robin Bell told msnbc.com, the study redefines "how squishy" the base of ice sheets can be. "This matters to how fast ice will flow and how fast ice sheets will change."
"It also means that ice sheet models are not correct," she said, comparing it to "trying to figure out how a car will drive but forgetting to add the tires. The performance will be very different if you are driving on the rims."
Reporting in this week's issue of the peer-reviewed journal Science, Bell and his team described how ice-penetrating radar peeled back two miles of ice a million years old in the center of Antarctica.
The images show that refrozen ice makes up 24 percent of an area known as Dome A, a 13,800-foot-high plateau roughly the size of California. Much of the sheet and refrozen ice lies atop an underground mountain range.
Ice from that area "drains into all the major ice shelves of Antarctica," the researchers wrote in their study. "Processes occurring in the Dome A region have the potential to affect the majority of East Antarctica."
While the field work was far inland, Bell believes the same will hold true along the edges of the icy continent. (cont.)
(Excerpt) Read more at msnbc.msn.com ...
Ah. Compared to today's SUVs, is it safe to say the LUBs emitted enough carbon dioxide to warm the planet.
No, wait a minute. The planet was obviously already warm.
This is all so confusing. I need another beer.
So what use are ice cores beyond a limited depth?
There is another factor to be considered, but I get where you’re coming from. One thing we’ve learned about the earth is that some land masses, plates for instance, sink over the milinias with the massive weight of moutains (or ice) on top of them. As the glaceirs melted in North Amercia, land masses that we once depressed, rose up.
Wouldn’t some of this “equaling of the crust” have the effect of compensating for the loss of ice. I.e. Greenland would begin to rise as the enormous weight is relieved? All things being equal in a sphere, wouldn’t that cause another area to settle? Probably the ocean floor, for example?
I’m no scientist. In fact, I suck at complex mathematics so my theory is only that. What do you think?
Paris is at a latitude that puts it north of the northern tip of Maine, yet Paris experiences a much warmer climate. What makes this possible is the Gulf Stream, a convection current where warm water from the Gulf of Mexico flows past northern Europe.
What if, during the Medieval Warm Period, a segment of the Gulf Stream had flowed past Greenland? Southern Greenland is at the same latitude as northern Scotland.
iirc there were settlements in Labrador and Newfoundland, too.
You know that line in Led Zeppelin’s Immigrant Song? “On we sweep with threshing oar?”
Well, they were rowing SUVs.
True story.
I’ve got a technical background such that I could probably still figure out a way to get in on the gravy train.
But then you have to look at yourself in the mirror every morning, and that sort of kills the whole idea, at least for me . . .
I had a slightly different answer to #57, but close. See a couple above.
Yes, the Vikings landed there and set up colonies which they abandoned when the Medieval Warm Period ended and it got cold again.
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