West Antarctic Ice Sheet
There is almost always a dramatic story associated with the Western Antarctic Ice Sheet.
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Scientists estimate that the consequences of a sudden collapse would raise sea levels around the world up to twenty feet. Coastal cities such as New York and Miami would be under water.
That scenario is actually a toned down dramatic version of events. Scientists also estimate that the West Antarctic Ice Sheet has lost two-thirds of its total mass since its most recent glacial maximum (the largest ice mass it achieved) some 20,000 years ago. If the West Antarctic Ice Sheet were at its glacial maximum today, and experienced a sudden collapse, the sea level changes to follow might chase populations somewhere past the Appalachian Mountains to avoid the flooding.
Antarctica is a continent characterized by ice. The Western Antarctic Ice Sheet is the smaller of the two dominant ice sheets spread across the continent. This series of NASA maps compares current and glacial maximum examples of the East and West Antarctic Ice Sheets. The maps also easily show how the geological setting of the Eastern Antarctic Ice Sheet is not conducive to sudden collapse episodes. It lies relatively flat across a broad land mass encircled by oval shaped mountain ridges.
An examination of the Western Antarctic Ice Sheet shows a different geological setting. It is a huge mountain of ice, sunk about two and one-half miles (4 km) deep into the Ross Sea, and it leans against the sides of the Tranantarctic mountains. Scientists generally agree that a marine based ice sheet is more unstable than a land based ice sheet because of its consistent interaction with ocean tides and temperatures. Scientists adopt this form of reasoning to explain the ice sheet's consistent retreat over time. Scientists also generally use long term time spans like a 4,000-7,000 year range when discussing the possibility of its natural disappearance.
Today's real life drama along the West Antarctic Ice Sheet normally starts with a discussion of weather. It's cold in Antarctica. The McMurdo Research Station, located near the Western Antarctic Ice Sheet, has recorded temperatures approaching -58o F (-50o C).
The action continues with the people who work in such a cold environment. The Antarctic Drilling Team (ANDRILL) consists of some two hundred participants from five states. They recently set a world record, 1000 meters, for drilling depth in the seabed adjacent to the Western Antarctic Ice Sheet. They also achieved their goal of drilling 1,200 meters below the sea floor by year end 2006.
ANDRILL collected soil and ice samples to help scientists gain better knowledge of changes in the Western Antarctic Ice Sheet over a five million year time span. Scientists hope this knowledge will help then understand how current issues of climate change relate to past cases.
© 2007. Patricia A. Michaels.