Posted on 02/08/2006 3:52:36 PM PST by blam
Cold and Deep: Antarctica's Lake Vostok has two big neighbors
Sid Perkins
GREAT LAKES. Lake Vostok and the newly described 90°E and Sovetskaya Lakes lie beneath a kilometers-thick blanket of ice. The black square in the inset shows the outline of this satellite image on a map of Antarctica; the cross indicates the South Pole. R.E. Bell, et al.
Trapped beneath Antarctica's kilometers-thick ice sheet are two bodies of water that rival North America's Great Lakes, new analyses suggest. The geological setting of these huge, unfrozen lakes hints that they may harbor ecosystems that have been isolated for millions of years.
More than 140 lakes lie buried beneath varying thicknesses of Antarctic ice, but most of them are small and shallow, says Michael Studinger, a geophysicist at the Lamont-Doherty Earth Observatory in Palisades, N.Y. Lake Vostok, discovered decades ago, is the largest. It's the size of Connecticut and holds 5,400 cubic kilometers of water, enough to fill Lake Michigan.
Scientists who've drilled through Lake Vostok's overlying ice sheet to within 120 meters of the lake's upper surface have found microbes trapped in the ice (SN: 10/9/99, p. 230: http://www.sciencenews.org/pages/sn_arc99/10_9_99/fob6.htm). The researchers view that finding as a tantalizing clue that the lake may hold a thriving ecosystem.
Lake Vostok sits in a basin that formed as Earth's crust stretched thin, a feature that had set this body of water apart from all other subglacial Antarctic lakes, says Studinger. Now, he and his colleagues have used a collage of data to depict two large subglacial lakes near Lake Vostok and to determine that they also sit in basins formed by a thinning tectonic plate.
One of the lakes is dubbed 90°E because it stretches along that longitude. The other is called Sovetskaya, after the Russian research station atop it. Although scientists knew of these two lakes, they had no notion of their sizes until they saw recent satellite images of the region, says Studinger.
90°E Lake has a surface area of about 2,000 square kilometers, about half the size of Rhode Island, which makes it the second-largest known subglacial lake in Antarctica. It probably holds about 1,800 km3 of water, more than enough to fill Lake Ontario. Sovetskaya Lake covers about 1,600 km2. Studinger's team describes the lakes in the Jan. 28 Geophysical Research Letters.
Ice-penetrating-radar data gathered during aerial surveys indicate that the upper surfaces of these lakes lie beneath 4 km of ice. A new analysis of measurements of Earth's gravitational field suggests that the lakes in some places are about 900 m deep.
The lakes remain unfrozen because heat seeps up from Earth's interior and insulating blankets of ice lie above them, says Studinger. Any ecosystems now in the lakes would have been isolated from Earth's surface for 35 million years, the estimated age of the ice sheet in that region.
Because of their great sizes, the covered lakes probably have always contained at least some liquid water, says David M. Karl, an oceanographer at the University of Hawaii in Honolulu.
"This is an important discovery," says Karl. "It shows how little we know about the Earth around us."
Ping. You like this stuff.
35 million years is a lot longer than I thought.
Drill with 9.1 brine water.
A couple of barrels of salt water ain't gonna do anything to a lack that big, even if you lost circulation.
...think Jimmy Hoffa is somewhere down there?
It might be a bigger problem, if we contaminate us.
all this talk is making me thirsty.
Antarctic stories always leave me cold.
Old punch line: "Yeah, and it's deep too!"
"These pretzels are making me thirsty..."
It would seem that there might be a lot of potential pressure under all that ice. Wouldn't breaching that cause a pretty impressive geyser?
No:
You:(1) case the hole (metal piping as you go);(2) have what is called a pressure control stack on the surface (blow out preventers and a annular) in the event you become underbalanced; and (3) most importantly, you have a colum of drilling fluid of some kind weighing down the formation (lake, in this instance) . . water being the lightest, to brine (all you'd need here), or even some sort of heavier petroleum based mud.
Yes, I am a drilling engineer.
Why are these lakes warm enough to remain unfrozen when everything else in the neighborhood is frozen to the depth of 4km?
Isn't that basin where The Thing's spaceship crashed as shown in the movie?
and the bottom's sandy.
Loaded with bacteria, germs and etc.
Too bad the real author, John W. Campbell Jr., never gets much credit for his original pulp story "Who Goes There?" It was in the great 1930s style of purple prose and bodice-ripping BEMs (Bug-Eyed Monsters) but Lordy I loved 'em!
The 1950s movie version did something revolutionary for the time. It only showed scary glimpses of the alien monster (aka 'Marshall' James Arness) and built suspense until the final confrontation when the Thing was at last revealed.
Heating from below; areas where the crust is thinner and you've got magma nearer the surface.
Use Bentonite with their density-improver Weight-it. at an Sg of 1.6, ought to work pretty well with a column like that!
Pro-mud polymer drilling fluid is fun stuff, too, but you have to run a Ph of 13 to make it really work, and to keep the density up.
However, arent' they just drilling ice? How do you restrain the casing fdrom moving ineither direction? I can't imagine there is much skin friction holding the string.
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