Environmental Engineering Reference
In-Depth Information
Antarctica
Nearly all of Antarctica is covered by an ice sheet that
is, on average, 8,000 feet thick and has a volume of about 1,900
cubic miles. About 90 percent of all the ice on the globe is on the
Antarctic continent. If all of this were to melt, following the lead of
Greenland, the ocean would rise by 260 feet (fi gure 9.4). Current
ice loss is as much as 36 cubic miles per year, 2 percent of the total
Antarctic ice, and is the main source of the ice that fuels global sea
level rise.
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Most of the ice in Antarctica is in the East Antarctic Ice Sheet (EAIS),
which had been thought to be stable, with ice accumulation from snow-
fall balancing the loss from melting. But since 2006, net melting has
occurred at the fringes of the ice sheet. Complete melting of the EAIS
would raise sea level by 211 feet, submerging a large part of the east
coast of the United States.
The Greenland-sized West Antarctic Ice Sheet (WAIS) makes up about
20 percent of Antarctica's surface area and stores the frozen water
equivalent of 26 feet of global sea level.
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The temperature on the Ant-
arctic Peninsula, the northwestern extension of West Antarctica, has
risen by 5ºF since the 1950s, among the largest warming signals on earth.
The biggest of the WAIS glaciers, the Pine Island Glacier, is moving 40
percent faster than it was in the 1970s, discharging water and ice more
Figure 9.4
Location of the shoreline around conterminous United States 18,000 years ago at the height
of the last glaciation and where the shoreline would be if all of the planet's ice melted.
Many states along the Atlantic and Gulf coasts would disappear.
