Day 2 - Antarctica

 

Antarctica:  Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of 5,500,000 square miles. Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of 1.2 miles.

Antarctica is on average the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over 8 inches along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which if melted would raise global sea levels by almost 200 feet. Antarctica holds the record for the lowest measured temperature on Earth, -128.6° F. The coastal regions can reach temperatures over 50° F in summer. Native species of animals include mites, nematodes, penguins, seals, and tardigrades. Where vegetation occurs, it is mostly in the form of lichen or moss.

The ice shelves of Antarctica were probably first seen in 1820, during a Russian expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Lazarev. The decades that followed saw further exploration in French, American, and British expeditions. The first confirmed landing was by a Norwegian team in 1895. In the early 20th century, there were a few expeditions into the interior of the continent. British explorers were the first to reach the magnetic South Pole in 1909, and the geographic South Pole was first reached in 1911 by Norwegian explorers.

Antarctica is governed by about 30 countries, all of which are parties of the 1959 Antarctic Treaty System. According to the terms of the treaty, military activity, mining, nuclear explosions, and nuclear waste disposal are all prohibited in Antarctica. Tourism, fishing, and research are the main human activities in and around Antarctica. During the summer months, about 5,000 people reside at research stations, a figure that drops to around 1,000 in the winter. Despite its remoteness, human activity has a significant impact on the continent via pollution, ozone depletion, and climate change.

Positioned asymmetrically around the South Pole and largely south of the Antarctic Circle (one of the five major circles of latitude that mark maps of the world), Antarctica is surrounded by the Southern Ocean. Rivers exist in Antarctica, the longest being the Onyx. Antarctica covers more than 5,500,000 square miles, making it the fifth-largest continent, slightly less than 1.5 times the area of the United States. Its coastline is almost 11,200 miles long. As of 1983, of the four coastal types, 44% of the coast is floating ice in the form of an ice shelf, 38% consists of ice walls that rest on rock, 13% is ice streams or the edge of glaciers, and the remaining 5% is exposed rock.

The lakes that lie at the base of the continental ice sheet occur mainly in the McMurdo Dry Valleys or various oases. Lake Vostok, discovered beneath Russia's Vostok Station, is the largest sub-glacial lake globally, and one of the largest lakes in the world. It was once believed that the lake had been sealed off for millions of years, but scientists now estimate its water is replaced by the slow melting and freezing of ice caps every 13,000 years. During the summer, the ice at the edges of the lakes can melt, and liquid moats temporarily form. Antarctica has both saline and freshwater lakes.

Antarctica is divided into West Antarctica and East Antarctica by the Transantarctic Mountains, which stretch from Victoria Land to the Ross Sea. The vast majority of Antarctica is covered by the Antarctic ice sheet, which averages 1.2 miles in thickness. The ice sheet extends to all but a few oases, which, with the exception of the McMurdo Dry Valleys, are located in coastal areas. Several Antarctic ice streams flow to one of the many Antarctic ice shelves, a process described by ice-sheet dynamics.

Vinson Massif from the northwest, the highest peak in Antarctica

East Antarctica comprises Coats Land, Queen Maud Land, Enderby Land, Mac. Robertson Land, Wilkes Land, and Victoria Land. All but a small portion of the region lies within the Eastern Hemisphere. East Antarctica is largely covered by the East Antarctic Ice Sheet. There are numerous islands surrounding Antarctica, most of which are volcanic and very young by geological standards. The most prominent exceptions to this are the islands of the Kerguelen Plateau, the earliest of which formed around 40 Ma.

Vinson Massif, in the Ellsworth Mountains, is the highest peak in Antarctica at 16,050 feet. Mount Erebus on Ross Island is the world's southernmost active volcano and erupts around 10 times each day. Ash from eruptions has been found 190 miles from the volcanic crater. There is evidence of a large number of volcanoes under the ice, which could pose a risk to the ice sheet if activity levels were to rise. The ice dome known as Dome Argus in East Antarctica is the highest Antarctic ice feature, at 13,422 feet. It is one of the world's coldest and driest places—temperatures there may reach as low as -130° F, and the annual precipitation is 0.39–1.18 inches. 

More info:  https://en.wikipedia.org/wiki/Antarctica