Antarctica is the southernmost and coldest continent on Earth, with not a single state, but many arctic volcanoes! There are also about 90 scientific stations and bases on the continent of different countries, and no minerals are mined there, although there are plenty of them. Officially it was discovered by Russian explorers Fabian Bellingshausen and Mikhail Lazarev in 1820, although as a hypothetical continent it was already mapped by the ancient scholar Claudius Ptolemy (150 AD), the Turkish admiral Pirireis (1513), and a number of other maps XV-XVIII centuries. The name “Antarctica,” in use since the 1890s, is of Greek origin and means «opposite to the north».
This continent is washed by the waters of the Atlantic, Indian and Pacific Oceans, although the International Hydrographic Organization in 2000 proposed to call the waters south of 60 degrees south latitude the Southern Ocean.
Antarctica covers about 14.11 million square kilometers (of which the ice shelves cover about 0.93 million square kilometers and the islands 0.08 million square kilometers). There are more than 100 volcanoes under Antarctica. The South geographic pole is located 660 km from the conventional center of the continent. Its coastline is more than 30 thousand km long, is poorly indented, and mainly consists of glacial precipices up to several tens of meters high.
Within Antarctica there is the lowest air temperature (to minus 93,2 degrees Celsius), the lowest amount of precipitation (on average only 18 mm per year, i.e. more than 4 times less than in Sahara), the lowest relative humidity, the strongest wind (up to 250-320 km/h) and the most intense solar radiation on the planet. The average temperature in winter ranges from minus 60 to minus 70 degrees Celsius, and in summer from minus 25 to minus 45 degrees Celsius. And only on the coasts it ranges from minus 8 to minus 35 degrees Celsius in winter and from zero to plus 5 degrees Celsius in summer. An interesting fact: winter in the Southern Hemisphere lasts from June to August, and summer – from December to February.
Antarctica is the highest continent on Earth with the ongoing Antarctic volcanic activity, the average height of its surface above sea level is more than 2 km (which is almost 3 times higher than the average height of all the other continents). However, the main part of this height is a permanent ice sheet with an average thickness of 2.5 km, and in some central parts of the continent – up to 4.3 km. As you may know, the bulk of ice on Earth is in Antarctica. On average, the ice sheet has a dome shape with decreasing thickness and increasing surface steepness closer to the coast, wherein many places it is framed by ice shelves. Therefore, when ice accumulates under the action of gravity, it slowly “flows” to the ocean, where the ice eventually breaks away as icebergs (about 2,500 cubic kilometers per year). It is amazing that such a continent has its unique ice volcanoes on Earth! From the center of the continent, where the density of settled cold air at the surface increases significantly, the strongest runoff winds blow towards the coast: in the winter season (from April to November) – around the clock, and during the rest of the time – at night.
Despite the fact that the territory of Antarctica as a whole is rather tectonically calm and almost aseismic, it is, oddly enough, home to the largest fire and ice volcano area in the world. How many volcanoes in Antarctica, you ask? In the mainland and its adjacent islands to date, 138 volcanoes have been discovered – extinct, dormant and active, small and giant, protruding above the ice sheet and completely hidden under it, basaltic shield-like and cone-shaped stratovolcanoes, continental, island and underwater. At least 18 of them are active or dormant, including 7 underwater.
Most Antarctica volcanoes are located along the west coast of the continent within one of the Earth’s largest alkaline (mainly basaltic) volcanic provinces, which exists in conjunction with the West Antarctic Rift System, stretching for 3.2 thousand km and has a width of about 700 km. In this system the lithosphere is thinned, major faults pass through and the tectonic plates separate. This allows molten magma to rise close to the Earth’s surface and even go outside, which explains the existence of the Antarctica active volcanoes (as in other rift zones of the planet). There is also an extensive volcanic field in the north of the Antarctic Peninsula, which arose during the Andes mountain formation.
As a whole, the Antarctic volcanic belt can be traced from the sub-Antarctic South Sandwich Islands through the Antarctic Peninsula and Mary Bird Land to East Antarctica at a distance of about 5 thousand km. Geothermal sources of mineralized water and fumaroles (places where volcanic gases escape) are associated with some volcanoes (including the subglacial volcanoes). The highest volcano on the white continent is the extinct Sidley, the height of which, according to various sources, is 4181 or 4285 meters above sea level (it is the sixth-highest peak in Antarctica). And the largest of the detected craters is underwater and has a diameter of about 5 km (fortunately, this giant is already extinct).
It is often impossible to directly observe the eruptions of active volcanoes in Antarctica, because there are too few people on the white continent. Therefore, in some cases, detecting recent volcanic activity is helped, for example, by satellite images. This is how the explosive and effusive eruptions of the Belinda volcano on Antarctic Montague Island in the South Sandwich Islands archipelago, which woke up in 2001, were detected. We know one more huge island with volcanoes, which is Greenland. The Greenland volcanoes are dangerous as well and if you want to know more about volcanoes in Greenland, stay tuned and continue reading our blog!
Antarctic volcanoes are mostly completely buried under a thick ice sheet, so it is very difficult to study their present activity and past eruptions. Although the use of airborne GPR sounding, drilling, and studying ice core samples, which may contain ash and aerosol traces of eruptions, provide important information, including with respect to the dating of events. Occasionally, ice-free outcrops of volcanic rocks are also found, allowing relevant studies to be carried out. There exists a special antarctic volcanoes map, which you can easily find on the Internet and understand the location of the most active volcano in Antarctica. Scientists have been able to identify numerous subglacial volcanic eruptions and some Greenland volcanic activity over at least the last 100,000 years.
For example, on Mary Bird Earth, American researchers have discovered an active subglacial volcano, whose explosive antarctic volcano eruption 8 thousand years ago broke through the ice sheet and was covered with ash (now hidden under the ice), a huge area. Moreover, in 2010 and 2011 some activity of this volcano was already recorded, including abnormally high mobility of the glacier above it. Since the polar ice caps not melting slowly and volcanoes are currently covered by a thickness of only 1 km of ice, sooner or later their eruptions may again break through the ice above the crater.
Another case happened near Pine Island in Pine Island glacier volcano, where British scientists have discovered a volcano under the ice sheet, a layer of ash from an explosive eruption of which in the IV or III century BC covered an area of 23 thousand square kilometers (but then also disappeared under new layers of ice). That means that the ice sheet was also completely penetrated by the volcanic fire under the surface and through a huge hole in it a column of volcanic gases and ash rose to a presumable height of 12 km.
Radar and other studies have shown that many subglacial Antarctic volcanoes are still unbroken by the slowly sliding ice sheet and are cone-shaped, though often with flattened tops from ice pressure, but still with steep slopes. This means that they may well be active or dormant. The most famous is the most active volcano in Antarctica and the southernmost active volcano on Earth – Erebus, the upper part of which significantly protrudes above the ice sheet, but it is also covered with sliding glaciers up to 50-300 m thick. It is located on Ross Island in the sea of the same name not far from the mainland coast. On the same island there are 3 more large volcanoes, but extinct. What would happen if a volcano erupted in Antarctica? If eruptions occur, it could further destabilize some of the region’s ice sheets, which have already been affected by global warming. Volcanoes will melt huge caves at the base of the ice and create gigantic amounts of meltwater. That means that a volcanic eruption occurring beneath an ice sheet is likely to cause huge cataclysms all over the world and wipe out many islands and even continents!
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