Chapter 2: Antarctica

The world has seven continents. Rated by physical area from the largest to the smallest, they are Asia, Africa, North America, South America, Antarctica, Europe, and Australia.

Antarctica, which is larger than Australia and 1.3 times larger than Europe, is located entirely south of 60° latitude and is surrounded by the Southern Ocean.

Antarctica has the highest average elevation of any continent; there are many mountain ranges. The two-thousand-mile-long Transantarctic Mountain range divides Antarctica into a small western region and a larger eastern region. At both ends of the Transantarctic Mountains are the two main ice shelves: the Ross Ice Shelf and the Ronne Ice Shelf. The Ellsworth Mountains are located in the western region and are home to Mt. Vinson (or the Vinson Massif), which is the highest peak on the continent, reaching an elevation of 16,050 feet. This is higher than any mountain in the contiguous, continental United States, Europe, or Australia.

Antarctica isn’t politically controlled by any one government. Forty-six countries are now included in the Antarctic Treaty. The treaty, designed to protect the environment and encourage scientific research, prohibits military activities, mineral mining, and the disposal of waste products.

All land claims were suspended when the Antarctic Treaty was initiated, but the claims are not without political ramifications. Antarctica is divided into pie-shaped sections, and each of the original claimant countries is allocated a portion, according to their claim. The countries with original claims are Norway, New Zealand, France, Chile, Australia, and Argentina. Other countries, including Brazil, Peru, Russia, South Africa, Spain, and the United States, have reserved their right to submit claims on the continent in the future if the issue of territorial claims becomes significant. A large sector of West Antarctica called Marie Byrd Land remains unclaimed.

The Southern Ocean, which surrounds the continent of Antarctica,  has a northern boundary located south of 60° latitude even though the actual limit has not yet been firmly agreed upon.

The Southern Ocean’s northern boundary has more to do with marine conditions. There is a transition called the Subtropical Convergence in which the cold, dense waters of the Southern Ocean meet up with the warmer waters of the Pacific, Atlantic, and Indian Oceans. The cold, dense water from the south sinks below the warm waters from the north to create a zone of upwelling and mixing that is conducive to high levels of productivity for organisms such as phytoplankton and krill.

The zone of Subtropical Convergence can be visually observed by the grayish, cold southern waters meeting up with the bluish-green, warm northern waters. The krill, which thrive on phytoplankton, are an important link in the food chain for marine organism such as fish, penguins, seals, albatrosses, and whales in the Southern Ocean.

About 98 percent of Antarctica is covered by an ice sheet that is, on average, up to a mile deep. In some areas, it is nearly three miles deep. In the winter season, the ice sheet’s area might double as it extends out from the coastline. The Antarctic ice sheet holds about 70 percent of the earth’s fresh water. If the ice sheet were to melt, the sea level could rise considerably and cover many of the earth’s low-lying islands, peninsulas, and coastal regions with low elevations. Antarctica is considered a desert because it usually averages fewer than ten inches of precipitation per year. Coastal regions annually receive as much as four feet of snow, while the interior near the South Pole might only receive a few inches.

The Antarctic Peninsula is actually an extension of the Andes Mountains of South America and is home to active volcanoes. The peninsula is the location of a volcano on Deception Island that erupted in the late 1960s and destroyed research stations in the area. There was an additional large eruption in 1970. The volcano continues to show activity, and sightings of lava flow continue to be reported.

There are areas in Antarctica that are not covered with ice but have a landscape of bare ground. This non-ice portion of the continent protrudes above the ice sheet and only covers a combined physical area equivalent to about half the US state of Kentucky. The only plant life that exists here are the many different mosses and lichens that grow during short periods of the year. Below the giant ice sheet are dozens of subglacial lakes. Lake Vostok, the largest lake discovered in the Antarctic so far, was found two miles below the ice sheet and is the size of Lake Ontario.

It is unknown what aquatic life might exist in these lakes. If all the ice and snow were removed from the continent, the total land area would be considerably smaller and would consist mainly of mountain ranges and islands. Some estimate that this land area altogether would only equate to about one hundred thousand square miles, roughly equivalent to the physical area of the US state of Colorado. This does not account for the fact that if all the ice were to melt, the sea level would rise and cover more land area. The land portion of the continent would also expand upward because of the loss of the weight of the ice, which has been compressing the continent.

Not only is Antarctica the driest continent with the least average annual precipitation and the highest continent in average elevation; it is also the coldest of the continents. The lowest temperature ever recorded on Earth was −128 °F in 1983 at a Russian research station in Antarctica. Temperatures reach a minimum of less than −110 °F in winter in the interior and greater than 55 °F near the coast in summer. No permanent human settlements exist in Antarctica other than research stations from a number of countries.

Research stations account for the entire human population in Antarctica. Approximately one thousand people live in Antarctica year-round, and up to five thousand or more live there during the summer months. Many of the research stations rotate their personnel, and tours of duty last anywhere from a few months to a year or more. Various family groups have worked there as well as other service workers, including Russian Orthodox priests, who have rotated every year at one of the Russian research stations.

Tourism brings the largest number of additional people to the continent. Tourists come for short-term visits to experience the conditions or see the many species of penguins or fauna that exist here. More than forty-five thousand tourists visit the Antarctic Treaty area yearly. Most arrive on commercial ships that specialize in tours of the region. Tours only last one or two weeks.

Visit Antarctica via Google Earth! Click here to explore.

Key Takeaways:

✎ Antarctica has the highest average elevation of any continent.
✎ Antarctica isn’t politically controlled by any one government.
✎ About 98 percent of Antarctica is covered by an ice sheet that holds about 70% of the Earth’s fresh water.
✎ Antarctica the coldest and driest continent.

Next: Chapter 3: North America

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Image and additional information credits:

Antarctica
By Landsat Image Mosaic of Antarctica team – extracted from http://lima.nasa.gov/pdf/A3_overview.pdf, Public Domain, https://commons.wikimedia.org/w/index.php?curid=9570048
Mt. Erebus
By Richard Waitt, U.S. Geological Survey – U.S. Geological Survey (USGS), Public Domain, https://commons.wikimedia.org/w/index.php?curid=340317
Lake Vostok
By Nicolle Rager-Fuller / NSF – US National Science Foundation, Public Domain, https://commons.wikimedia.org/w/index.php?curid=18309720
Antarctica territorial claims
By A loose necktie – Own work, however This file was derived from:  Antarctica, territorial claims.svg by Lokal_Profil, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=68782366
Antarctica research station
By Gary Bembridge from London, UK – Brown Research Station Paradise Bay Antarctica 4, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=84691460