The Earth’s polar regions are not familiar places to most people. Flat maps often show them as a distorted place at the top and bottom. Globes need to be examined more closely to see them. The support of the globe is in the way. My goal is to help make the polar regions more familiar, to point out features, and to identify things important to climate research. There will be three posts in the Polar Ice series. This post has a focus on the Antarctic. The next one will focus on the Arctic. The third will compare the Arctic and Antarctic regions noting important changes related to climate change.
Antarctica is 1.4 times larger in area than the United States. A small part of Antarctica, the size of Denmark, is snow and ice free. The 3300 km Transantarctic Mountain Range divides Antarctica in East and West parts. Starting from the South Pole, travel along the Prime Meridian to the north or top of the image, you will eventually pass through Greenwich, England. Travel along the 90˚W meridian and you will pass through the Galapagos Islands, Central America, and up the Mississippi River valley through St. Louis, Missouri. Travel the 90˚E meridian and pass through the Indian Ocean, east of India, China, western Mongolia, and Russia. The 180˚ meridian passes through the Pacific Ocean, goes west of Hawaii, and traverses the east Siberian region.
The continent is classified as a desert with less than 10″ (254 mm) of equivalent liquid from the snowfall. The interior gets less than 2″ (50 mm). Coastal areas can receive as much as 8″ (200 mm) of precipitation. None of the snow melts and has built up into a layer averaging over 1800 meters thick. The maximum is 4776 m (3 miles). Because of the tremendous weight of snow and ice, it tends to flow toward lower elevation and to the sea.
The ice flows occur at nearly all of the perimeter of Antarctica to some relatively small scale. Two places have especially large regions where these flows create shelves of thick ice out over the water. They are the Ross and the Ronne ice shelves seen in the map above. The following cross-sectional diagram shows how they extend and calve off icebergs into the sea. Icebergs are much more submerged than indicated in the diagram.
The NASA Scientific Visualization Studio released this animation showing the ice flow and underlying bedrock beneath the ice sheet.
No single government rules Antarctica. Eight nations claim some territory. There are 29 nations which have research stations.
http://lima.usgs.gov/ A zoomable map of the Antarctic from years of Landsat imagery.