
Antarctica () is
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
's southernmost and least-populated
continent
A continent is any of several large geographical regions. Continents are generally identified by convention (norm), convention rather than any strict criteria. A continent could be a single large landmass, a part of a very large landmass, as ...
. Situated almost entirely south of the
Antarctic Circle
The Antarctic Circle is the most southerly of the five major circles of latitude that mark maps of Earth. The region south of this circle is known as the Antarctic, and the zone immediately to the north is called the Southern Temperate Zone. So ...
and surrounded by the
Southern Ocean
The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the world ocean, generally taken to be south of 60th parallel south, 60° S latitude and encircling Antarctica. With a size of , it is the seco ...
(also known as the Antarctic Ocean), it contains the geographic
South Pole
The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is the point in the Southern Hemisphere where the Earth's rotation, Earth's axis of rotation meets its surface. It is called the True South Pole to distinguish ...
. Antarctica is the fifth-largest continent, being about 40% larger than
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
, and has an area of . Most of Antarctica is covered by the
Antarctic ice sheet
The Antarctic ice sheet is a continental glacier covering 98% of the Antarctic continent, with an area of and an average thickness of over . It is the largest of Earth's two current ice sheets, containing of ice, which is equivalent to 61% of ...
, with an average thickness of .
Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average
elevation
The elevation of a geographic location (geography), ''location'' is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational equipotenti ...
. It is mainly a
polar desert
Polar deserts are the regions of Earth that fall under an ice cap climate (''EF'' under the Köppen classification). Despite rainfall totals low enough to normally classify as a desert, polar deserts are distinguished from true deserts (' or ' un ...
, with annual
precipitation
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...
of over along the
coast
A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...
and far less inland. About 70% of the world's
freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...
reserves are frozen in Antarctica, which, if melted, would raise global
sea level
Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...
s by almost . Antarctica holds the record for the
lowest measured temperature on Earth, . The coastal regions can reach temperatures over in the summer. Native
species of animals include
mite
Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as eac ...
s,
nematode
The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (h ...
s,
penguin
Penguins are a group of aquatic flightless birds from the family Spheniscidae () of the order Sphenisciformes (). They live almost exclusively in the Southern Hemisphere. Only one species, the Galápagos penguin, is equatorial, with a sm ...
s,
seals and
tardigrade
Tardigrades (), known colloquially as water bears or moss piglets, are a phylum of eight-legged segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them . In 1776, th ...
s. Where
vegetation
Vegetation is an assemblage of plants and the ground cover they provide. It is a general term, without specific reference to particular Taxon, taxa, life forms, structure, Spatial ecology, spatial extent, or any other specific Botany, botanic ...
occurs, it is mostly in the form of
lichen
A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...
or
moss
Mosses are small, non-vascular plant, non-vascular flowerless plants in the taxonomic phylum, division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Wilhelm Philippe Schimper, Schimp. 1879) may also refer to the parent group bryo ...
.
The
ice shelves of Antarctica were probably first seen in 1820, during
a Russian expedition led by
Fabian Gottlieb von Bellingshausen
Faddey Faddeyevich Bellingshausen or Fabian Gottlieb Benjamin von Bellingshausen ( – ) was a Russian cartographer, explorer, and naval officer of Baltic German descent, who attained the rank of admiral. He participated in the first Russi ...
and
Mikhail Lazarev. The decades that followed saw further
exploration
Exploration is the process of exploring, an activity which has some Expectation (epistemic), expectation of Discovery (observation), discovery. Organised exploration is largely a human activity, but exploratory activity is common to most organis ...
by 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 Robert Falcon Scott
Captain Robert Falcon Scott (6 June 1868 – ) was a British Royal Navy officer and explorer who led two expeditions to the Antarctic regions: the Discovery Expedition, ''Discovery'' expedition of 1901–04 and the Terra Nova Expedition ...
and
Ernest Shackleton
Sir Ernest Henry Shackleton (15 February 1874 – 5 January 1922) was an Anglo-Irish Antarctic explorer who led three British expeditions to the Antarctic. He was one of the principal figures of the period known as the Heroic Age of Antarcti ...
were the first to reach the
magnetic South Pole in 1909, and the
geographic South Pole was first reached in 1911 by
Norwegian explorer Roald Amundsen
Roald Engelbregt Gravning Amundsen (, ; ; 16 July 1872 – ) was a Norwegians, Norwegian explorer of polar regions. He was a key figure of the period known as the Heroic Age of Antarctic Exploration.
Born in Borge, Østfold, Norway, Am ...
.
Antarctica is
governed by about 30 countries, all of which are parties of the 1959
Antarctic Treaty System
The Antarctic Treaty and related agreements, collectively known as the Antarctic Treaty System (ATS), regulate international relations with respect to Antarctica, Earth's only continent without a native human population. It was the first arms ...
. According to the terms of the treaty, military activity, mining,
nuclear explosion
A nuclear explosion is an explosion that occurs as a result of the rapid release of energy from a high-speed nuclear reaction. The driving reaction may be nuclear fission or nuclear fusion or a multi-stage cascading combination of the two, th ...
s, and
nuclear waste disposal
Radioactive waste is a type of hazardous waste that contains radioactive material. It is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, nuclear decommissioning, rare-earth mining, and nucle ...
are all prohibited in Antarctica.
Tourism
Tourism is travel for pleasure, and the Commerce, commercial activity of providing and supporting such travel. World Tourism Organization, UN Tourism defines tourism more generally, in terms which go "beyond the common perception of tourism as ...
, 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 the continent's remoteness, human activity has a significant effect on it via
pollution
Pollution is the introduction of contaminants into the natural environment that cause harm. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the component ...
,
ozone depletion
Ozone depletion consists of two related events observed since the late 1970s: a lowered total amount of ozone in Earth, Earth's upper atmosphere, and a much larger springtime decrease in stratospheric ozone (the ozone layer) around Earth's polar ...
, and
climate change
Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...
. The melting of the potentially unstable
West Antarctic ice sheet
The West Antarctic Ice Sheet (WAIS) is the segment of the Antarctic ice sheet, continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains that lies in the Western Hemisphere. It is cla ...
causes the most uncertainty in century-scale projections of
sea level rise
The sea level has been rising from the end of the last ice age, which was around 20,000 years ago. Between 1901 and 2018, the average sea level rose by , with an increase of per year since the 1970s. This was faster than the sea level had e ...
, and the same melting also affects the
Southern Ocean overturning circulation
Southern Ocean overturning circulation (sometimes referred to as the Southern Meridional overturning circulation (SMOC) or Antarctic overturning circulation) is the southern half of a global thermohaline circulation, which connects different wate ...
, which can eventually lead to significant impacts on the
Southern Hemisphere climate and Southern Ocean productivity.
Etymology

The name given to the continent
originates from the word ''antarctic'', which comes from
Middle French
Middle French () is a historical division of the French language that covers the period from the mid-14th to the early 17th centuries. It is a period of transition during which:
* the French language became clearly distinguished from the other co ...
or () and, in turn, the
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
(). is derived from the
Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
() and (, ).
The Greek philosopher
Aristotle
Aristotle (; 384–322 BC) was an Ancient Greek philosophy, Ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, a ...
wrote in ''
Meteorology
Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agricultur ...
'' about an "Antarctic region" in . The Greek geographer
Marinus of Tyre
Marinus of Tyre (, ''Marînos ho Týrios''; 70–130) was a List of Graeco-Roman geographers, geographer, Cartography, cartographer and mathematician, who founded mathematical geography and provided the underpinnings of Claudius Ptolemy's i ...
reportedly used the name in his world map from the second century CE, now lost. The
Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of Roman civilization
*Epistle to the Romans, shortened to Romans, a letter w ...
authors
Gaius Julius Hyginus
Gaius Julius Hyginus (; 64 BC – AD 17) was a Latin author, a pupil of the scholar Alexander Polyhistor, and a freedman of Augustus, and reputed author of the '' Fabulae'' and the '' De astronomia'', although this is disputed.
Life and works ...
and
Apuleius
Apuleius ( ), also called Lucius Apuleius Madaurensis (c. 124 – after 170), was a Numidians, Numidian Latin-language prose writer, Platonist philosopher and rhetorician. He was born in the Roman Empire, Roman Numidia (Roman province), province ...
used for the South Pole the
romanised Greek name , from which derived the
Old French
Old French (, , ; ) was the language spoken in most of the northern half of France approximately between the late 8th [2-4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ...
(modern ) attested in 1270, and from there the Middle English , found first in a treatise written by the English author Geoffrey Chaucer.
Belief by Europeans in the existence of a —a vast continent in the far south of the globe to balance the northern lands of Europe, Asia, and North Africa—had existed as an intellectual concept since
classical antiquity
Classical antiquity, also known as the classical era, classical period, classical age, or simply antiquity, is the period of cultural History of Europe, European history between the 8th century BC and the 5th century AD comprising the inter ...
. The belief in such a land lasted until the European
discovery of Australia.
During the early 19th century, explorer
Matthew Flinders
Captain (Royal Navy), Captain Matthew Flinders (16 March 1774 – 19 July 1814) was a British Royal Navy officer, navigator and cartographer who led the first littoral zone, inshore circumnavigate, circumnavigation of mainland Australia, then ...
doubted the existence of a detached continent south of Australia (then called
New Holland) and thus advocated for the "Terra Australis" name to be used for Australia instead. In 1824, the colonial authorities in
Sydney
Sydney is the capital city of the States and territories of Australia, state of New South Wales and the List of cities in Australia by population, most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Syd ...
officially renamed the continent of New Holland to Australia, leaving the term "Terra Australis" unavailable as a reference to Antarctica. Over the following decades, geographers used phrases such as "the Antarctic Continent". They searched for a more poetic replacement, suggesting names such as ''Ultima'' and ''Antipodea''. ''Antarctica'' was adopted in the 1890s, with the first use of the name being attributed to the Scottish
cartographer
Cartography (; from , 'papyrus, sheet of paper, map'; and , 'write') is the study and practice of making and using maps. Combining science, aesthetics and technique, cartography builds on the premise that reality (or an imagined reality) can ...
John George Bartholomew.
Antarctica has also been known by the moniker ''Great White South'', after which British photographer
Herbert Ponting named one of his books on Antarctic photography, possibly as a counterpart to the epithet ''Great White North'' for
Canada
Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...
.
Geography

Positioned asymmetrically around the South Pole and largely south of the
Antarctic Circle
The Antarctic Circle is the most southerly of the five major circles of latitude that mark maps of Earth. The region south of this circle is known as the Antarctic, and the zone immediately to the north is called the Southern Temperate Zone. So ...
(one of the five major
circles of latitude that mark maps of the world), Antarctica is surrounded by the
Southern Ocean
The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the world ocean, generally taken to be south of 60th parallel south, 60° S latitude and encircling Antarctica. With a size of , it is the seco ...
.
Rivers
A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...
exist in Antarctica; the longest is the
Onyx
Onyx is a typically black-and-white banded variety of agate, a silicate mineral. The bands can also be monochromatic with alternating light and dark bands. ''Sardonyx'' is a variety with red to brown bands alternated with black or white bands. ...
. Antarctica covers more than , almost double the area of Australia, making it the fifth-largest continent, and comparable to the surface area of
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of Trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Su ...
. Its coastline is almost long:
, of the four coastal types, 44% of the coast is floating ice in the form of an
ice shelf
An ice shelf is a large platform of glacial ice floating on the ocean, fed by one or multiple tributary glaciers. Ice shelves form along coastlines where the ice thickness is insufficient to displace the more dense surrounding ocean water. T ...
, 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
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacier, glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice s ...
occur mainly in the
McMurdo Dry Valleys
The McMurdo Dry Valleys are a row of largely Antarctic oasis, snow-free valleys in Antarctica, located within Victoria Land west of McMurdo Sound. The Dry Valleys experience extremely low humidity and surrounding mountains prevent the flow of ...
or various
oases.
Lake Vostok
Lake Vostok () is the largest of Antarctica's 675 known subglacial lakes. Lake Vostok is located at the southern Pole of Cold, beneath Russia's Vostok Station under the surface of the central East Antarctic Ice Sheet, which is at above mean se ...
, discovered beneath Russia's
Vostok Station, is the largest
subglacial lake
A subglacial lake is a lake that is found under a glacier, typically beneath an ice cap or ice sheet. Subglacial lakes form at the boundary between ice and the underlying bedrock, where liquid water can exist above the lower melting point of ic ...
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
East Antarctica, also called Greater Antarctica, constitutes the majority (two-thirds) of the Antarctic continent, lying primarily in the Eastern Hemisphere south of the Indian Ocean, and separated from West Antarctica by the Transantarctic ...
by the
Transantarctic Mountains
The Transantarctic Mountains (abbreviated TAM) comprise a mountain range of uplifted rock (primarily sedimentary) in Antarctica which extends, with some interruptions, across the continent from Cape Adare in northern Victoria Land to Coats L ...
, which stretch from
Victoria Land
Victoria Land is a region in eastern Antarctica which fronts the western side of the Ross Sea and the Ross Ice Shelf, extending southward from about 70°30'S to 78th parallel south, 78°00'S, and westward from the Ross Sea to the edge of the Ant ...
to the
Ross Sea
The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who ...
. The vast majority of Antarctica is covered by the
Antarctic ice sheet
The Antarctic ice sheet is a continental glacier covering 98% of the Antarctic continent, with an area of and an average thickness of over . It is the largest of Earth's two current ice sheets, containing of ice, which is equivalent to 61% of ...
, which averages 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.
East Antarctica comprises
Coats Land
Coats Land is a region in Antarctica which lies westward of Queen Maud Land and forms the eastern shore of the Weddell Sea, extending in a general northeast–southwest direction between 20°00′W and 36°00′W. The northeast part was discover ...
,
Queen Maud Land
Queen Maud Land () is a roughly region of Antarctica Territorial claims in Antarctica, claimed by Norway as a dependent territory. It borders the claimed British Antarctic Territory 20th meridian west, 20° west, specifically the Caird Coast, ...
,
Enderby Land
Enderby Land is a projecting landmass of Antarctica. Its shore extends from Shinnan Glacier at about to William Scoresby Bay at , approximately of the earth's longitude (planets), longitude. It was first documented in western and eastern liter ...
,
Mac. Robertson Land,
Wilkes Land, and Victoria Land. All but a small portion of the region lies within the
Eastern Hemisphere
The Eastern Hemisphere is the half of the planet Earth which is east of the prime meridian (which crosses Greenwich, London, United Kingdom) and west of the antimeridian (which crosses the Pacific Ocean and relatively little land from pole to p ...
. East Antarctica is largely covered by the
East Antarctic Ice Sheet
The East Antarctic Ice Sheet (EAIS) lies between 45th meridian west, 45° west and 168th meridian east, 168° east longitudinally. It was first formed around 34 million years ago, and it is the largest ice sheet on the entire planet, with far gre ...
. There are numerous
islands
This is a list of the lists of islands in the world grouped by country, by continent, by body of water, and by other classifications. For rank-order lists, see the #Other lists of islands, other lists of islands below.
Lists of islands by count ...
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 Kerguelen Plateau (, ), also known as the Kerguelen–Heard Plateau, is an oceanic plateau and large igneous province (LIP) located on the Antarctic Plate, in the southern Indian Ocean. It is about to the southwest of Australia and is near ...
, the earliest of which formed around 40
Ma.
[
]Vinson Massif
Vinson Massif () is a large mountain massif in Antarctica that is long and wide and lies within the Sentinel Range of the Ellsworth Mountains. It overlooks the Ronne Ice Shelf near the base of the Antarctic Peninsula. The massif is located ab ...
, in the Ellsworth Mountains
The Ellsworth Mountains are the highest mountain ranges in Antarctica, forming a long and wide chain of mountains in a north to south configuration on the western margin of the Ronne Ice Shelf in Marie Byrd Land. They are bisected by Minneso ...
, is the highest peak in Antarctica at . Mount Erebus on Ross Island
Ross Island is an island in Antarctica lying on the east side of McMurdo Sound and extending from Cape Bird in the north to Cape Armitage in the south, and a similar distance from Cape Royds in the west to Cape Crozier in the east.
The isl ...
is the world's southernmost active volcano
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most oft ...
and erupts around 10 times each day. Ash from eruptions has been found from the volcanic crater
A volcanic crater is an approximately circular depression in the ground caused by volcanic activity. It is typically a bowl-shaped feature containing one or more vents. During volcanic eruptions, molten magma and volcanic gases rise from an ...
. 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 . It is one of the world's coldest and driest places—temperatures there may reach as low as , and the annual precipitation is .
Geologic history
From the end of the Neoproterozoic
The Neoproterozoic Era is the last of the three geologic eras of the Proterozoic geologic eon, eon, spanning from 1 billion to 538.8 million years ago, and is the last era of the Precambrian "supereon". It is preceded by the Mesoproterozoic era an ...
era to the Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
, Antarctica was part of the supercontinent
In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", ...
Gondwana
Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...
. Modern Antarctica was formed as Gondwana gradually broke apart beginning around 183 Ma. For a large proportion of the Phanerozoic
The Phanerozoic is the current and the latest of the four eon (geology), geologic eons in the Earth's geologic time scale, covering the time period from 538.8 million years ago to the present. It is the eon during which abundant animal and ...
, Antarctica had a tropical
The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...
or temperate climate
In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ra ...
, and it was covered in forests.
Paleozoic era (540–250 Ma)
During the Cambrian period
The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovici ...
, Gondwana had a mild climate. West Antarctica was partially in the Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...
, and during the time, large amounts of sandstone
Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...
s, limestone
Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...
s, and shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...
s were deposited. East Antarctica was at the equator
The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...
, where seafloor invertebrate
Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...
s and trilobite
Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most succ ...
s flourished in the tropical seas. By the start of the Devonian period
The Devonian ( ) is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at million years ago ( Ma), to the beginning of the succeeding C ...
(416 Ma), Gondwana was in more southern latitudes, and the climate was cooler, though fossils of land plants are known from then. Sand and silt
Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually ...
s were laid down in what is now the Ellsworth, Horlick, and Pensacola Mountains
The Pensacola Mountains () are a large group of mountain ranges and peaks that extend in a northeast–southwest direction in the Transantarctic Mountains System, Queen Elizabeth Land region of Antarctica.
They comprise the Argentina Range, Forre ...
.
Antarctica became glaciated during the Late Paleozoic icehouse beginning at the end of the Devonian period (360 Ma), though glaciation would substantially increase during the late Carboniferous
The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...
. It drifted closer to the South Pole, and the climate cooled, though flora
Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...
remained. After deglaciation during the latter half of the Early Permian
The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...
, the land became dominated by glossopterids (an extinct group of seed plants with no close living relatives), most prominently '' Glossopteris'', a tree interpreted as growing in waterlogged soils, which formed extensive coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal i ...
deposits. Other plants found in Antarctica during the Permian include Cordaitales
Cordaitales are an extinct order of gymnosperms, known from the early Carboniferous to the late Permian. Many Cordaitales had elongated strap-like leaves, resembling some modern-day conifers of the Araucariaceae and Podocarpaceae. They had co ...
, sphenopsids, ferns, and lycophyte
The lycophytes, when broadly circumscribed, are a group of vascular plants that include the clubmosses. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest lineag ...
s. At the end of the Permian, the climate became drier and hotter over much of Gondwana, and the glossopterid forest ecosystems collapsed, as part of the End-Permian mass extinction. There is no evidence of any tetrapod
A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetr ...
s having lived in Antarctica during the Paleozoic.
Mesozoic era (250–66 Ma)
The continued warming dried out much of Gondwana. During the Triassic
The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...
period, Antarctica was dominated by seed ferns (pteridosperms) belonging to the genus '' Dicroidium'', which grew as trees. Other associated Triassic flora included ginkgophytes, cycad
Cycads are seed plants that typically have a stout and woody (ligneous) trunk (botany), trunk with a crown (botany), crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants o ...
ophytes, conifer
Conifers () are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sin ...
s, and sphenopsids. Tetrapod
A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetr ...
s first appeared in Antarctica during the Early Triassic
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which ...
epoch
In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured.
The moment of epoch is usually decided b ...
, with the earliest known fossils found in the Fremouw Formation of the Transantarctic Mountains. Synapsid
Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant rept ...
s (also known as "mammal-like reptiles") included species such as '' Lystrosaurus'', and were common during the Early Triassic
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.9 Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which ...
.
The Antarctic Peninsula
The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martin in Argentina, and originally as Graham Land in the United Kingdom and the Palmer Peninsula in the United States, is the northernmost part of mainland Antarctica.
...
began to form during the Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...
period (). Africa separated from Antarctica in the Jurassic around 160 Ma, followed by the Indian subcontinent
The Indian subcontinent is a physiographic region of Asia below the Himalayas which projects into the Indian Ocean between the Bay of Bengal to the east and the Arabian Sea to the west. It is now divided between Bangladesh, India, and Pakista ...
in the early Cretaceous (about 125 Ma). ''Ginkgo
''Ginkgo'' is a genus of non-flowering seed plants, assigned to the gymnosperms. The scientific name is also used as the English common name. The order to which the genus belongs, Ginkgoales, first appeared in the Permian, , and ''Ginkgo'' is n ...
'' trees, conifers, Bennettitales
Bennettitales (also known as cycadeoids) is an extinct order of seed plants that first appeared in the Permian period and became extinct in most areas toward the end of the Cretaceous. Bennettitales were amongst the most common seed plants of th ...
, horsetails, ferns and cycads were plentiful during the time. About 80 million years ago, flowering plants became the most diverse groups of plants on the continent. In West Antarctica, coniferous forests dominated throughout the Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
period (146–66 Ma), though southern beech trees (''Nothofagus
''Nothofagus'', also known as the southern beeches, is a genus of 43 species of trees and shrubs native to the Southern Hemisphere, found across southern South America (Chile, Argentina) and east and southeast Australia, New Zealand, New Guin ...
'') became prominent towards the end of the Cretaceous. Ammonite
Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...
s were common in the seas around Antarctica, and dinosaurs were also present, though only a few Antarctic dinosaur genera
Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...
('' Cryolophosaurus'' and ''Glacialisaurus
''Glacialisaurus'' is a genus of sauropodomorph dinosaur from the Early Jurassic period (geology), period of Antarctica. It is known from two specimens; the holotype (name-bearing specimen), a partial Tarsus (skeleton), tarsus (ankle) and Metata ...
'', from the Early Jurassic Hanson Formation
The Hanson Formation (also known as the Shafer Peak Formation) is a geologic formation on Mount Kirkpatrick and north Victoria Land, Ross Dependency, Antarctica. It is one of the two major dinosaur-bearing rock groups found on Antarctica to date; ...
of the Transantarctic Mountains, and ''Antarctopelta
''Antarctopelta'' (; meaning 'Antarctic shield') is a genus of ankylosaurian dinosaur, a group of large, quadrupedal herbivores, that lived during the Maastrichtian stage of the Late Cretaceous period on what is now James Ross Island, Antarctica ...
'', ''Trinisaura
''Trinisaura'' is a genus of ornithopod dinosaur that lived during the late Campanian stage of the Late Cretaceous, Upper Cretaceous, around 73 to 72 million years ago in what is now James Ross Island off the coast of northern Antarctica near Pa ...
'', '' Morrosaurus'' and ''Imperobator
''Imperobator'' ("powerful warrior") is a genus of probable unenlagiid Paraves, paravian theropod dinosaurs, that lived during the Maastrichtian age of the Late Cretaceous in what is now James Ross Island in Antarctica. ''Imperobator'' is one of ...
'' from Late Cretaceous of the Antarctic Peninsula) have been described.
Cenozoic era before present (66–10 Ma)
During the early Paleogene
The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...
, the Antarctic land bridge
The Antarctic land bridge was a land bridge connecting the continents of South America, Antarctica, and Australia that existed from the Late Cretaceous to the Late Eocene. The land bridge consisted of the entire continent of Antarctica (at the time ...
continued to connect Antarctica with South America as well as to southeastern Australia. Fauna from the La Meseta Formation in the Antarctic Peninsula, dating to the Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
, is very similar to equivalent South American faunas; with marsupial
Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...
s, xenarthra
Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a superorder and major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and ...
ns, litoptern, and astrapotheria
Astrapotheria is an extinct order of South American and Antarctic hoofed mammals that existed from the late Paleocene to the Middle Miocene, ."The uruguaytheriine Astrapotheriidae from the rich middle Miocene Honda Group of the upper Magdalena R ...
n ungulate
Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...
s, as well as gondwanatheres and possibly meridiolestida
Meridiolestida is an extinct clade of mammals known from the Cretaceous and Cenozoic of South America and possibly Antarctica. They represented the dominant group of mammals in South America during the Late Cretaceous. Meridiolestidans were morph ...
ns. Marsupials are thought to have dispersed into Australia from South America via Antarctica by the early Eocene.
Around 53 Ma, Australia-New Guinea
New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...
separated from Antarctica, opening the Tasmanian Passage
The Tasmanian Passage, also Tasmanian Gateway or Tasmanian Seaway, is the name of ocean waters between Australia (continent), Australia and Antarctica.
It was formed from the separation of the two continental plates of Australia and Antarctica a ...
. The Drake Passage
The Drake Passage is the body of water between South America's Cape Horn, Chile, Argentina, and the South Shetland Islands of Antarctica. It connects the southwestern part of the Atlantic Ocean (Scotia Sea) with the southeastern part of the Pa ...
opened between Antarctica and South America around 30 Ma, resulting in the creation of the Antarctic Circumpolar Current that completely isolated the continent. Models of Antarctic geography suggest that this current, as well as a feedback loop
Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause and effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handle ...
caused by lowering CO2 levels, caused the creation of small yet permanent polar ice caps. As CO2 levels declined further the ice began to spread rapidly, replacing the forests that until then had covered Antarctica. Tundra
In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...
ecosystems continued to exist on Antarctica until around 14–10 million years ago, when further cooling lead to their extermination.
Present day
The geology
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...
of Antarctica, largely obscured by the continental ice sheet, is being revealed by techniques such as remote sensing
Remote sensing is the acquisition of information about an physical object, object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring inform ...
, ground-penetrating radar
Ground-penetrating radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. It is a non-intrusive method of surveying the sub-surface to investigate underground utilities such as concrete, asphalt, metals, pipes, cables ...
, and satellite imagery
Satellite images (also Earth observation imagery, spaceborne photography, or simply satellite photo) are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell im ...
. Geologically, West Antarctica closely resembles the South American Andes
The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...
. The Antarctic Peninsula was formed by geologic uplift and the transformation of sea bed sediment
Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...
s into metamorphic rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...
s.
West Antarctica was formed by the merging of several continental plates, which created a number of mountain ranges in the region, the most prominent being the Ellsworth Mountains. The presence of the West Antarctic Rift System has resulted in volcanism
Volcanism, vulcanism, volcanicity, or volcanic activity is the phenomenon where solids, liquids, gases, and their mixtures erupt to the surface of a solid-surface astronomical body such as a planet or a moon. It is caused by the presence of a he ...
along the border between West and East Antarctica, as well as the creation of the Transantarctic Mountains.
East Antarctica is geologically varied. Its formation began during the Archean
The Archean ( , also spelled Archaean or Archæan), in older sources sometimes called the Archaeozoic, is the second of the four geologic eons of Earth's history of Earth, history, preceded by the Hadean Eon and followed by the Proterozoic and t ...
Eon (4,000 Ma2,500 Ma), and stopped during the Cambrian Period. It is built on a craton
A craton ( , , or ; from "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two topmost layers, the crust and the uppermost mantle. Having often survived cycles of merging and rifting of contine ...
of rock, which is the basis of the Precambrian Shield
A shield is a piece of personal armour held in the hand, which may or may not be strapped to the wrist or forearm. Shields are used to intercept specific attacks, whether from close-ranged weaponry like spears or long ranged projectiles suc ...
. On top of the base are coal and sandstones, limestones, and shales that were laid down during the Devonian and Jurassic periods to form the Transantarctic Mountains. In coastal areas such as the Shackleton Range and Victoria Land, some faulting
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...
has occurred.
Coal was first recorded in Antarctica near the Beardmore Glacier
The Beardmore Glacier in Antarctica is one of the largest valley glaciers in the world, being long and having a width of .
It descends about from the Antarctic Plateau to the Ross Ice Shelf and is bordered by the Commonwealth Range of the Queen ...
by Frank Wild
John Robert Francis Wild (18 April 1873 – 19 August 1939) was an English sailor and explorer. He participated in five expeditions to Antarctica during the Heroic Age of Antarctic Exploration, for which he was awarded the Polar Medal ...
on the ''Nimrod'' Expedition in 1907, and low-grade coal is known to exist across many parts of the Transantarctic Mountains. The Prince Charles Mountains
The Prince Charles Mountains are a major group of mountains in Mac. Robertson Land in Antarctica, including the Athos Range, the Porthos Range, and the Aramis Range. The highest peak is Mount Menzies, with a height of . Other prominent peaks ...
contain deposits of iron ore
Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the f ...
. There are oil and natural gas field
A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the prese ...
s in the Ross Sea.
Climate
Antarctica is the coldest, windiest, and driest of Earth's continents.
Near the coast, the temperature can exceed 10 °C in summer and fall to below −40 °C in winter. Over the elevated inland, it can rise to about −30 °C in summer but fall below −80 °C in winter.
The lowest natural air temperature ever recorded on Earth was at the Russian Vostok Station in Antarctica on 21 July 1983. A lower air temperature of was recorded in 2010 by satellite—however, it may have been influenced by ground temperatures and was not recorded at a height of above the surface as required for official air temperature records. Antarctica is colder than the Arctic
The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway ( ...
region, as much of Antarctica is over above sea level, where air temperatures are colder. The relative warmth of the Arctic Ocean
The Arctic Ocean is the smallest and shallowest of the world's five oceanic divisions. It spans an area of approximately and is the coldest of the world's oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, ...
is transferred through the Arctic sea ice
The Arctic ice pack is the sea ice cover of the Arctic Ocean and its vicinity. The Arctic ice pack undergoes a regular seasonal cycle in which ice melts in spring and summer, reaches a minimum around mid-September, then increases during fall a ...
and moderates temperatures in the Arctic region.
Winds are strong and persistent.
Antarctica is a polar desert
Polar deserts are the regions of Earth that fall under an ice cap climate (''EF'' under the Köppen classification). Despite rainfall totals low enough to normally classify as a desert, polar deserts are distinguished from true deserts (' or ' un ...
with little precipitation
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...
; the continent receives an average equivalent to about of water per year, mostly in the form of snow. The interior is dryer and receives less than per year, whereas the coastal regions typically receive more than . In a few blue-ice areas, the wind and sublimation remove more snow than is accumulated by precipitation. In the dry valleys, the same effect occurs over a rock base, leading to a barren and desiccated landscape.
Regional differences
East Antarctica is colder than its western counterpart because of its higher elevation. Weather front
A weather front is a boundary separating air masses for which several characteristics differ, such as air density, wind, temperature, and humidity. Disturbed and unstable weather due to these differences often arises along the boundary. For ins ...
s rarely penetrate far into the continent, leaving the centre cold and dry, with moderate wind speeds. Heavy snowfalls are common on the coastal portion of Antarctica, where snowfalls of up to in 48 hours have been recorded. At the continent's edge, strong katabatic wind
A katabatic wind (named ) is a downslope wind caused by the flow of an elevated, high-density air mass into a lower-density air mass below under the force of gravity. The spelling catabatic is also used. Since air density is strongly dependent o ...
s off the polar plateau often blow at storm force. During the summer, more solar radiation
Sunlight is the portion of the electromagnetic radiation which is emitted by the Sun (i.e. solar radiation) and received by the Earth, in particular the visible light perceptible to the human eye as well as invisible infrared (typically p ...
reaches the surface at the South Pole than at the equator
The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...
because of the 24 hours of sunlight received there each day.
Climate change
Ozone depletion
Scientists have studied the ozone layer
The ozone layer or ozone shield is a region of Earth's stratosphere that absorption (electromagnetic radiation), absorbs most of the Sun's ultraviolet radiation. It contains a high concentration of ozone (O3) in relation to other parts of the a ...
in the atmosphere
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...
above Antarctica since the 1970s. In 1985, British scientists, working on data they had gathered at Halley Research Station on the Brunt Ice Shelf, discovered a large area of low ozone
Ozone () (or trioxygen) is an Inorganic compound, inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , break ...
concentration over Antarctica. The 'ozone hole' covers almost the whole continent and was at its largest in September 2006; the longest-lasting event occurred in 2020. The depletion is caused by the emission of chlorofluorocarbon
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are fully or partly Halogenation, halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F). They are produced as volatility (chemistry), volat ...
s and halons into the atmosphere, which causes ozone to break down into other gases. The extreme cold conditions of Antarctica allow polar stratospheric clouds to form. The clouds act as catalysts
Catalysis () is the increase in reaction rate, rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst ...
for chemical reactions, which eventually lead to the destruction of ozone. The 1987 Montreal Protocol
The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. It was agreed on 16 ...
has restricted the emissions of ozone-depleting substances. The ozone hole above Antarctica is predicted to slowly disappear; by the 2060s, levels of ozone are expected to have returned to values last recorded in the 1980s.
The ozone depletion can cause a cooling of around in the stratosphere
The stratosphere () is the second-lowest layer of the atmosphere of Earth, located above the troposphere and below the mesosphere. The stratosphere is composed of stratified temperature zones, with the warmer layers of air located higher ...
. The cooling strengthens the polar vortex and so prevents the outflow of the cold air near the South Pole, which in turn cools the continental mass of the East Antarctic ice sheet. The peripheral areas of Antarctica, especially the Antarctic Peninsula, are then subjected to higher temperatures, which accelerate the melting of the ice. Models suggest that ozone depletion and the enhanced polar vortex effect may also account for the period of increasing sea ice extent, lasting from when observation started in the late 1970s until 2014. Since then, the coverage of Antarctic sea ice has decreased rapidly.
Biodiversity
Most species in Antarctica seem to be the descendants of species that lived there millions of years ago. As such, they must have survived multiple glacial cycle
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and gr ...
s. The species survived the periods of extremely cold climate in isolated warmer areas, such as those with geothermal heat or areas that remained ice-free throughout the colder climate.
Animals
Invertebrate life of Antarctica includes species of microscopic mite
Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as eac ...
s such as '' Alaskozetes antarcticus'', lice
Louse (: lice) is the common name for any member of the infraorder Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera was previously recognized as an order, until a 2021 genetic study determined th ...
, flea
Flea, the common name for the order (biology), order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by hematophagy, ingesting the blood of their hosts. Adult f ...
s (''Glaciopsyllus antarcticus''), nematodes
The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (he ...
, tardigrade
Tardigrades (), known colloquially as water bears or moss piglets, are a phylum of eight-legged segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them . In 1776, th ...
s, rotifer
The rotifers (, from Latin 'wheel' and 'bearing'), sometimes called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic Coelom#Pseudocoelomates, pseudocoelomate animals.
They were first describ ...
s, krill
Krill ''(Euphausiids)'' (: krill) are small and exclusively marine crustaceans of the order (biology), order Euphausiacea, found in all of the world's oceans. The name "krill" comes from the Norwegian language, Norwegian word ', meaning "small ...
and springtail
Springtails (class Collembola) form the largest of the three lineages of modern Hexapoda, hexapods that are no longer considered insects. Although the three lineages are sometimes grouped together in a class called Entognatha because they have in ...
s. The flightless midge
A midge is any small fly, including species in several family (biology), families of non-mosquito nematoceran Diptera. Midges are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid ...
''Belgica antarctica
''Belgica antarctica'', the Antarctic midge, is a species of flightless midge, endemic to the continent of Antarctica. At long, it is the largest purely terrestrial animal native to the continent. It also has the smallest known insect genome as ...
'', the largest purely terrestrial animal in Antarctica, reaches in size.
Antarctic krill
Antarctic krill (''Euphausia superba'') is a species of krill found in the Antarctica, Antarctic waters of the Southern Ocean. It is a small, swimming crustacean that lives in large schools, called swarms, sometimes reaching densities of 10,000� ...
, which congregates in large schools
A school is the educational institution (and, in the case of in-person learning, the building) designed to provide learning environments for the teaching of students, usually under the direction of teachers. Most countries have systems of ...
, is the keystone species
A keystone species is a species that has a disproportionately large effect on its natural environment relative to its abundance. The concept was introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in main ...
of the ecosystem
An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...
of the Southern Ocean, being an important food organism for whales, seals, leopard seals, fur seals, squid
A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...
, icefish, and many bird species, such as penguins and albatross
Albatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Paci ...
es. Some species of marine animals exist and rely, directly or indirectly, on phytoplankton
Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...
. Antarctic sea life includes penguin
Penguins are a group of aquatic flightless birds from the family Spheniscidae () of the order Sphenisciformes (). They live almost exclusively in the Southern Hemisphere. Only one species, the Galápagos penguin, is equatorial, with a sm ...
s, blue whale
The blue whale (''Balaenoptera musculus'') is a marine mammal and a baleen whale. Reaching a maximum confirmed length of and weighing up to , it is the largest animal known ever to have existed. The blue whale's long and slender body can ...
s, orca
The orca (''Orcinus orca''), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant species in the genus '' Orcinus'', it is recognizable by its black-and-white-patterned body. A cosmopol ...
s, colossal squids and fur seal
Fur seals are any of nine species of pinnipeds belonging to the subfamily Arctocephalinae in the family Otariidae. They are much more closely related to sea lions than Earless seal, true seals, and share with them external ears (Pinna (anatomy ...
s. The Antarctic fur seal was very heavily hunted in the 18th and 19th centuries for its pelt
A fur is a soft, thick growth of hair that covers the skin of almost all mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an ...
by seal hunters from the United States and the United Kingdom. Leopard seals are apex predator
An apex predator, also known as a top predator or superpredator, is a predator at the top of a food chain, without natural predators of its own.
Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the hig ...
s in the Antarctic ecosystem and migrate across the Southern Ocean in search of food.
There are approximately 40 bird species that breed on or close to Antarctica, including species of petrel
Petrels are tube-nosed seabirds in the phylogenetic order Procellariiformes.
Description
Petrels are a monophyletic group of marine seabirds, sharing a characteristic of a nostril arrangement that results in the name "tubenoses". Petrels enco ...
s, penguins
Penguins are a group of aquatic flightless birds from the family Spheniscidae () of the order Sphenisciformes (). They live almost exclusively in the Southern Hemisphere. Only one species, the Galápagos penguin, is equatorial, with a sm ...
, cormorants, and gulls
Gulls, or colloquially seagulls, are seabirds of the subfamily Larinae. They are most closely related to terns and Skimmer (bird), skimmers, distantly related to auks, and even more distantly related to waders. Until the 21st century, most gul ...
. Various other bird species visit the ocean around Antarctica, including some that normally reside in the Arctic. The emperor penguin
The emperor penguin (''Aptenodytes forsteri'') is the tallest and heaviest of all living penguin species and is Endemism in birds, endemic to Antarctica. The male and female are similar in plumage and size, reaching in length and weighing fr ...
is the only penguin that breeds during the winter in Antarctica; it and the Adélie penguin
The Adélie penguin (''Pygoscelis adeliae'') is a species of penguin common along the entire coast of the Antarctic continent, which is the only place where it is found. It is the most widespread penguin species, and, along with the emperor peng ...
breed farther south than any other penguin.
A Census of Marine Life by some 500 researchers during the International Polar Year was released in 2010. The research found that more than 235 marine organisms live in both polar regions, having bridged the gap of . Large animals such as some cetacean
Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively c ...
s and birds make the round trip annually. Smaller forms of life, such as sea cucumbers and free-swimming snails, are also found in both polar oceans. Factors that may aid in their distribution include temperature differences between the deep ocean at the poles and the equator of no more than and the major current systems or marine conveyor belts which are able to transport eggs and larva
A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...
.
Fungi
About 1,150 species of fungi
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
have been recorded in the Antarctic region, of which about 750 are non-lichen
A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...
-forming. Some of the species, having evolved under extreme conditions, have colonised structural cavities within porous rocks and have contributed to shaping the rock formations of the McMurdo Dry Valleys and surrounding mountain ridges.
The simplified morphology
Morphology, from the Greek and meaning "study of shape", may refer to:
Disciplines
*Morphology (archaeology), study of the shapes or forms of artifacts
*Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...
of such fungi, along with their similar biological structures, metabolism systems capable of remaining active at very low temperatures, and reduced life cycles, make them well suited to such environments. Their thick-walled and strongly melanised cells make them resistant to UV radiation. An Antarctic endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
species, the crust-like lichen '' Buellia frigida'', has been used as a model organism
A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Mo ...
in astrobiology
Astrobiology (also xenology or exobiology) is a scientific field within the List of life sciences, life and environmental sciences that studies the abiogenesis, origins, Protocell, early evolution, distribution, and future of life in the univ ...
research.
The same features can be observed in algae and cyanobacteria
Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteri ...
, suggesting that they are adaptation
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the p ...
s to the conditions prevailing in Antarctica. This has led to speculation that life on Mars
The possibility of life on Mars is a subject of interest in astrobiology due to the planet's proximity and similarities to Earth. To date, no conclusive evidence of past or present life has been found on Mars. Cumulative evidence suggests that ...
might have been similar to Antarctic fungi, such as '' Cryomyces antarcticus'' and '' Cryomyces minteri''. Some of the species of fungi, which are apparently endemic to Antarctica, live in bird dung, and have evolved so they can grow inside extremely cold dung, but can also pass through the intestines of warm-blooded animals.
Plants
Throughout its history, Antarctica has seen a wide variety of plant life. In the Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
, it was dominated by a fern-conifer
Conifers () are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sin ...
ecosystem, which changed into a temperate rainforest
Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...
by the end of that period. During the colder Neogene
The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...
(17–2.5 Ma), a tundra
In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...
ecosystem replaced the rainforests. The climate of present-day Antarctica does not allow extensive vegetation to form. A combination of freezing temperatures, poor soil quality
Soil quality refers to the condition of soil based on its capacity to perform ecosystem services that meet the needs of human and non-human life.Tóth, G., Stolbovoy, V. and Montanarella, 2007. Soil Quality and Sustainability Evaluation - An integ ...
, and a lack of moisture and sunlight inhibit plant growth, causing low species diversity
Species diversity is the number of different species that are represented in a given community (a dataset). The effective number of species refers to the number of equally abundant species needed to obtain the same mean proportional species abundan ...
and limited distribution. The flora
Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...
largely consists of bryophyte
Bryophytes () are a group of embryophyte, land plants (embryophytes), sometimes treated as a taxonomic Division (taxonomy), division referred to as Bryophyta ''Sensu#Common qualifiers, sensu lato'', that contains three groups of non-vascular pla ...
s (25 species of liverworts
Liverworts are a group of non-vascular plant, non-vascular embryophyte, land plants forming the division Marchantiophyta (). They may also be referred to as hepatics. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in wh ...
and 100 species of moss
Mosses are small, non-vascular plant, non-vascular flowerless plants in the taxonomic phylum, division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Wilhelm Philippe Schimper, Schimp. 1879) may also refer to the parent group bryo ...
es). There are three species of flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
s, all of which are found in the Antarctic Peninsula: '' Deschampsia antarctica'' (Antarctic hair grass), '' Colobanthus quitensis'' (Antarctic pearlwort) and the non-native '' Poa annua'' (annual bluegrass).
Other organisms
Of the 700 species of algae in Antarctica, around half are marine phytoplankton
Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...
. Multicoloured snow algae are especially abundant in the coastal regions during the summer. Even sea ice
Sea ice arises as seawater freezes. Because ice is less density, dense than water, it floats on the ocean's surface (as does fresh water ice). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world' ...
can harbour unique ecological communities, as it expels all salt from the water when it freezes, which accumulates into pockets of brine
Brine (or briny water) is a high-concentration solution of salt (typically sodium chloride or calcium chloride) in water. In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawat ...
that also harbour dormant microorganisms. When the ice begins to melt, brine pockets expand and can combine to form brine channels, and the algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...
inside the pockets can reawaken and thrive until the next freeze. Bacteria have also been found as deep as under the ice. It is thought to be likely that there exists a native bacterial community within the subterranean water body of Lake Vostok
Lake Vostok () is the largest of Antarctica's 675 known subglacial lakes. Lake Vostok is located at the southern Pole of Cold, beneath Russia's Vostok Station under the surface of the central East Antarctic Ice Sheet, which is at above mean se ...
. The existence of life there is thought to strengthen the argument for the possibility of life on Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined a ...
's moon Europa, which may have water beneath its water-ice crust. There exists a community of extremophile bacteria in the highly alkaline waters of Lake Untersee. The prevalence of highly resilient creatures in such inhospitable areas could further bolster the argument for extraterrestrial life in cold, methane-rich environments.
Conservation and environmental protection
The Agreed Measures for the Conservation of Antarctic Fauna and Flora, first international agreement to protect Antarctica's biodiversity was adopted in 1964. The overfishing of krill
Krill ''(Euphausiids)'' (: krill) are small and exclusively marine crustaceans of the order (biology), order Euphausiacea, found in all of the world's oceans. The name "krill" comes from the Norwegian language, Norwegian word ', meaning "small ...
(an animal that plays a large role in the Antarctic ecosystem) led officials to enact regulations on fishing. The Convention for the Conservation of Antarctic Marine Living Resources, an international treaty that came into force in 1980, regulates fisheries, aiming to preserve ecological relationships. Despite these regulations, illegal, unreported and unregulated fishing, illegal fishing—particularly of the highly prized Patagonian toothfish which is marketed as Chilean sea bass in the U.S.—remains a problem.
In analogy to the 1980 treaty on Sustainable fishery, sustainable fishing, countries led by New Zealand and the United States negotiated a treaty on mining. This Convention on the Regulation of Antarctic Mineral Resources, Convention on the Regulation of Antarctic Mineral Resource Activities was adopted in 1988. After a strong campaign from environmental organisations, first Australia and then France decided not to ratify the treaty. Instead, countries adopted the Protocol on Environmental Protection to the Antarctic Treaty (the Madrid Protocol), which entered into force in 1998. The Madrid Protocol bans all mining, designating the continent as a "natural reserve devoted to peace and science".
The pressure group Greenpeace established World Park Base, a base on Ross Island from 1987 to 1992 as part of its attempt to establish the continent as a Transboundary protected area, World Park. The Southern Ocean Whale Sanctuary was established in 1994 by the International Whaling Commission. It covers and completely surrounds the Antarctic continent. All commercial whaling is banned in the zone, though Japan has continued to hunt whales in the area, ostensibly for research purposes.
Despite these protections, the biodiversity in Antarctica is still at risk from human activities. Antarctic Specially Protected Area, Specially protected areas cover less than 2% of the area and provide better protection for Charismatic species, animals with popular appeal than for less visible animals. There are more terrestrial protected areas than marine protected areas. Ecosystems are impacted by local and global threats, notably pollution
Pollution is the introduction of contaminants into the natural environment that cause harm. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the component ...
, the Invasive species, invasion of non-native species, and the various Climate change in Antarctica, effects of climate change.
History of exploration
Early world maps, like the Piri Reis map, 1513 Piri Reis map, feature the hypothetical continent ''Terra Australis''. Much larger than and unrelated to Antarctica, ''Terra Australis'' was a landmass that Classical antiquity, classical scholars presumed necessary to balance the known lands in the northern hemisphere.
James Cook, Captain James Cook's ships, and , crossed the Antarctic Circle on 17 January 1773, in December 1773, and again in January 1774. Cook came within about of the Antarctic coast before retreating in the face of field ice in January 1773. In 1775, he called the existence of a polar continent "probable", and in another copy of his General journal, journal he wrote: "[I] firmly believe it and it's more than probable that we have seen a part of it".
19th century
Seal hunting, Sealers were among the earliest to go closer to the Antarctic landmass, perhaps in the earlier part of the 19th century. The oldest known human remains in the Antarctic region was a skull, dated from 1819 to 1825, that belonged to a young woman on Yamana Beach at the South Shetland Islands. The woman, who was likely to have been part of a Seal hunting, sealing expedition, was found in 1985.
The first person to see Antarctica or its ice shelf was long thought to have been the British sailor Edward Bransfield, a captain in the Royal Navy, who discovered the tip of the Antarctic peninsula on 30 January 1820. However, a captain in the Imperial Russian Navy, Fabian Gottlieb von Bellingshausen
Faddey Faddeyevich Bellingshausen or Fabian Gottlieb Benjamin von Bellingshausen ( – ) was a Russian cartographer, explorer, and naval officer of Baltic German descent, who attained the rank of admiral. He participated in the first Russi ...
, recorded seeing an ice shelf on 27 January. The American sealer Nathaniel Palmer, whose sealing ship was in the region at this time, may also have been the first to sight the Antarctic Peninsula.
The First Russian Antarctic Expedition, led by Bellingshausen and Mikhail Lazarev on the 985-ton sloop-of-war Vostok (sloop-of-war), ''Vostok'' and the 530-ton support vessel Mirny (sloop-of-war), ''Mirny'', reached a point within of Queen Maud's Land, Queen Maud Land and recorded sighting an ice shelf at , on 27 January 1820. The sighting happened three days before Bransfield sighted the land of the Trinity Peninsula of Antarctica, as opposed to the ice of an ice shelf, and 10 months before Palmer did so in November 1820. The first documented landing on Antarctica was by the English-born American sealer John Davis (sealer), John Davis, apparently at Hughes Bay on 7 February 1821, although some historians dispute this claim, as there is no evidence Davis landed on the Antarctic continent rather than an offshore island.
On 22 January 1840, two days after the discovery of the coast west of the Balleny Islands, some members of the crew of the 18371840 expedition of the French explorer Jules Dumont d'Urville disembarked on the Dumoulin Islands, off the coast of Adélie Land, where they took some mineral, algae, and animal samples, erected the French flag, and claimed French Territorial claims in Antarctica, sovereignty over the territory. The American captain Charles Wilkes led an expedition in 1838–1839 and was the first to claim he had discovered the continent. The British naval officer James Clark Ross failed to realise that what he referred to as "the various patches of land recently discovered by the American, French and English navigators on the verge of the Antarctic Circle" were connected to form a single continent. The American explorer Mercator Cooper landed on East Antarctica on 26 January 1853.
The first confirmed landing on the continental mass of Antarctica occurred in 1895 when the Norwegian-Swedish whaling ship Antarctic (ship), ''Antarctic'' reached Cape Adare.
20th century
During the ''Nimrod'' Expedition led by the British explorer Ernest Shackleton
Sir Ernest Henry Shackleton (15 February 1874 – 5 January 1922) was an Anglo-Irish Antarctic explorer who led three British expeditions to the Antarctic. He was one of the principal figures of the period known as the Heroic Age of Antarcti ...
in 1907, parties led by Edgeworth David became the first to climb Mount Erebus and to reach the South Magnetic Pole, south magnetic pole. Douglas Mawson, who assumed the leadership of the Magnetic Pole party on their perilous return, retired in 1931. Between December 1908 and February 1909, Shackleton and three members of his expedition became the first humans to traverse the Ross Ice Shelf, the first to cross the Transantarctic Mountains (via the Beardmore Glacier), and the first to set foot on the south Polar Plateau. On 14 December 1911, Amundsen's South Pole expedition, an expedition led by Norwegian explorer Roald Amundsen
Roald Engelbregt Gravning Amundsen (, ; ; 16 July 1872 – ) was a Norwegians, Norwegian explorer of polar regions. He was a key figure of the period known as the Heroic Age of Antarctic Exploration.
Born in Borge, Østfold, Norway, Am ...
from the ship ''Fram (ship), Fram'' became the first to reach the geographic South Pole, using a route from the Bay of Whales and up the Axel Heiberg Glacier. One month later, the doomed Terra Nova Expedition, ''Terra Nova'' Expedition reached the pole.
The American explorer Richard E. Byrd led four expeditions to Antarctica during the 1920s, 1930s, and 1940s, using the first mechanised Transport in Antarctica, tractors. His expeditions conducted extensive geographical and scientific research, and he is credited with surveying a larger region of the continent than any other explorer. In 1937, Ingrid Christensen became the first woman to step onto the Antarctic mainland. Caroline Mikkelsen had landed on an island of Antarctica, earlier in 1935.
The South Pole was next reached on 31 October 1956, when a U.S. Navy group led by Rear Admiral George J. Dufek landed an aircraft there. Six women were flown to the South Pole as a publicity stunt in 1969. In the summer of 19961997, Norwegian explorer Børge Ousland became the first person to cross Antarctica alone from coast to coast, helped by a kite on parts of the journey. Ousland holds the record for the fastest unsupported journey to the South Pole, taking 34 days.
Demographics
The first semi-permanent inhabitants of regions near Antarctica (areas situated south of the Antarctic Convergence) were British and American sealers who used to spend a year or more on South Georgia and the South Sandwich Islands, South Georgia, from 1786 onward. During the whaling era, which lasted until 1966, the population of the island varied from over 1,000 in the summer (over 2,000 in some years) to some 200 in the winter. Most of the whalers were Norwegian, with an increasing proportion from Britain.
Antarctica's population consists mostly of the staff of research stations in Antarctica (which are continuously maintained despite the population decline in the winter), although there are 2 all-civilian bases in Antarctica: the Esperanza Base and the Villa Las Estrellas, Villa Las Estrellas base. The number of people conducting and supporting scientific research and other work on the continent and its nearby islands varies from about 1,200 in winter to about 4,800 in the summer, with an additional 136 people in the winter to 266 people in the summer from the 2 civilian bases (as of 2017). Some of the research stations are staffed year-round, the winter-over personnel typically arriving from their home countries for a one-year assignment. The Russian Orthodox Church, Russian Orthodox Trinity Church (Antarctica), Holy Trinity Church at the Bellingshausen Station on King George Island (South Shetland Islands), King George Island opened in 2004; it is staffed year-round by one or two priests, who are similarly rotated every year.
The first child born in the southern polar region was a Norwegian girl, Solveig Gunbjørg Jacobsen, born in Grytviken on 8 October 1913. Emilio Marcos Palma was the first person born south of the 60th parallel south and the first to be born on the Antarctic mainland at the Esperanza Base of the Argentine Army, on 7 January 1978.
The Antarctic Treaty System, Antarctic Treaty prohibits any Military activity in the Antarctic, military activity in Antarctica, including the establishment of military bases and fortifications, military manoeuvres, and weapons testing. Military personnel or equipment are permitted only for scientific research or other peaceful purposes. Operación 90, Operation 90 by the Military of Argentina, Argentine military in 1965 was conducted to strengthen Argentina's claim in Antarctica.
Antarctic English, a distinct variety of the English language, has been found to be spoken by people living on Antarctica and the subantarctic islands.
Politics
Antarctica's status is regulated by the 1959 Antarctic Treaty and other related agreements, collectively called the Antarctic Treaty System. Antarctica is defined as all land and ice shelves south of 60° S for the purposes of the Treaty System. The treaty was signed by twelve countries, including the Soviet Union, the United Kingdom, Argentina, Chile, Australia, and the United States. Since 1959, a further 42 countries have Vienna Convention on the Law of Treaties#Signature, ratification and accession, acceded to the treaty. Countries can participate in decision-making if they can demonstrate that they do significant research on Antarctica; , 29 countries have this 'consultative status'. Decisions are based on Consensus decision-making, consensus, instead of a Voting, vote. The treaty set aside Antarctica as a scientific preserve and established freedom of scientific investigation and environmental protection.
Territorial claims
In 1539, the Monarchy of Spain, King of Spain, Charles V, Holy Roman Emperor, Charles V, created the Governorate of Terra Australis, which encompassed lands south of the Strait of Magellan and thus theoretically Antarctica, the existence of which was only hypothesized at the time, granting this Governorate to Pedro Sancho de la Hoz, who in 1540 transferred the title to the conquistador Pedro de Valdivia. Spain claimed all the territories to the south of the Strait of Magellan until the South Pole
The South Pole, also known as the Geographic South Pole or Terrestrial South Pole, is the point in the Southern Hemisphere where the Earth's rotation, Earth's axis of rotation meets its surface. It is called the True South Pole to distinguish ...
, with eastern and western borders to these claims specified in the Treaty of Tordesillas and Treaty of Zaragoza, Zaragoza respectively. In 1555 the claim was incorporated to Kingdom of Chile, Chile.
In the present, sovereignty over regions of Antarctica is claimed by seven different countries. While a few of these countries have mutually recognised each other's claims, the validity of the claims is not recognised universally. New claims on Antarctica have been suspended since 1959, although in 2015, Norway formally defined Queen Maud Land as including the unclaimed area between it and the South Pole.
The Argentine, British, and Chilean claims overlap and have caused friction. In 2012, after the British Foreign & Commonwealth Office designated a previously unnamed area Queen Elizabeth Land in tribute to Elizabeth II, Queen Elizabeth II's Diamond Jubilee of Elizabeth II, Diamond Jubilee, the Argentine government protested against the claim. The UK passed some of the areas it claimed to Australia and New Zealand after they achieved independence. The claims by Britain, Australia, New Zealand, France, and Norway do not overlap and are recognised by each other. Other member nations of the Antarctic Treaty do not recognise any claim, yet have shown some form of territorial interest in the past.
* has a designated "Brazilian Antarctica, zone of interest" that is not considered an actual claim.
* formally reserved its right to make a claim.
* inherited the Soviet Union's right to claim territory under the original Antarctic Treaty.
* formally reserved its right to make a claim.
* reserved its right to make a claim in the original Antarctic Treaty.
Economy and tourism
Deposits of coal, hydrocarbons, iron ore, platinum, copper, chromium, nickel, gold, and other minerals have been found in Antarctica, but not in large enough quantities to extract. The Protocol on Environmental Protection to the Antarctic Treaty, which came into effect in 1998 and is due to be reviewed in 2048, restricts the exploitation of Antarctic resources, including minerals.
Tourism, Tourists have been Tourism in Antarctica, visiting Antarctica since 1957. Tourism is subject to the provisions of the Antarctic Treaty and Environmental Protocol; the self-regulatory body for the industry is the International Association of Antarctica Tour Operators. Tourists arrive by small or medium ship at specific scenic locations with accessible concentrations of iconic wildlife. Over 74,000 tourists visited the region during the 2019–2020 season, of which 18,500 travelled on cruise ships but did not leave them to explore on land. The numbers of tourists fell rapidly after the start of the COVID-19 pandemic. Some nature conservation groups have expressed concern over the potential adverse effects caused by the influx of visitors and have called for limits on the size of visiting cruise ships and a tourism quota. The primary response by Antarctic Treaty parties has been to develop guidelines that set landing limits and closed or restricted zones on the more frequently visited sites.
Tourism in Antarctica is, in part, ecologically focused with expeditions being offered for bird watching tours due to the high numbers of Adélie penguin, Adélie, King penguin, King, and Gentoo penguinsamong other species. One site in particularMcDonald Beachis known to be a high-traffic area for tourists watching the Adélie penguins who number more than 40,000.
Overland sightseeing flights operated out of Australia and New Zealand until the Mount Erebus disaster in 1979, when an Air New Zealand plane crashed into Mount Erebus, killing all of the 257 people on board. Qantas resumed commercial overflights to Antarctica from Australia in the mid-1990s. There are many List of airports in Antarctica, airports in Antarctica.
Research
In 2017, there were more than 4,400 scientists undertaking research in Antarctica, a number that fell to just over 1,100 in the winter. There are over 70 permanent and seasonal research stations on the continent; the largest, United States' McMurdo Station, is capable of housing more than 1,000 people. The British Antarctic Survey has five major research stations on Antarctica, one of which is completely portable. The Belgian Princess Elisabeth Antarctica, Princess Elisabeth station is one of the most modern stations and the first to be Carbon neutrality, carbon-neutral. Argentina, Australia, Chile, and Russia also have a large scientific presence on Antarctica.
Geologists primarily study plate tectonics, meteorites, and the breakup of Gondwana. Glaciologists study the history and dynamics of floating ice, seasonal snow, glaciers, and ice sheets. Biologists, in addition to researching wildlife, are interested in how low temperatures and the presence of humans affect adaptation and survival strategies in organisms. Biomedical scientists have made discoveries concerning the spreading of viruses and the body's response to extreme seasonal temperatures.
The view of space from Earth is improved by a thinner atmosphere at higher elevations and a lack of water vapour in the atmosphere caused by freezing temperatures. Astrophysics, Astrophysicists at the Amundsen–Scott South Pole Station study cosmic microwave background radiation and neutrinos from space.
The largest neutrino detector in the world, the IceCube Neutrino Observatory, is at the Amundsen-Scott Station. It consists of around 5,500 Optical module, digital optical modules, some of which reach a depth of , that are held in of ice. Scientists also observed higher radiation dose rates around the coast of Antarctica compared with the global average: this is attributed to cosmic rays going through the thinner atmosphere compared to equatorial latitudes.
Antarctica provides a unique environment for the study of meteorites: the dry polar desert preserves them well, and meteorites older than a million years have been found. They are relatively easy to find, as the dark stone meteorites stand out in a landscape of ice and snow, and the flow of ice accumulates them in certain areas.
The Adelie Land meteorite, discovered in 1912, was the first to be found. Meteorites contain clues about the composition of the Solar System and its early development. Most meteorites come from asteroids, but a few meteorites found in Antarctica came from the Moon and Mars.
Major scientific organizations in Antarctica have released strategy and action plans focused on advancing national interests and objectives in Antarctica, supporting cutting-edge research to understand the interactions between the Antarctic region and climate systems. The British Antarctic Survey (BAS) released a 10-year (2023–2033) strategy report to reduce greenhouse gas emissions and to focus on creating sustainable living on Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
. Environmental sustainability is named as one of the top focus areas by the BAS strategy, highlighting the main challenge and priority to embed environmental sustainability into everything.
In 2022, the Australian Antarctic Program (AAP) released a new Strategy and 20-year Action Plan (2022–2036) to modernize its Antarctic program. The global climate system was highlighted as one of the main priorities that will be supported and studied through the AAP Strategy Plan. It emphasizes the importance of understanding the vital role of Antarctica and the Southern Ocean in climate and weather to improve current knowledge and inform management responses.
In 2021, the United States Antarctic Program (USAP) released a Midterm Assessment on the 2015 Strategic Vision for Antarctic and Southern Ocean Research, stressing the prominent role of the Southern Ocean in the global carbon cycle and sea level rise. The USAP outlines the Changing Antarctic Ice Sheets Initiative as a top priority to enhance understanding of why ice sheets are changing now, and how they will change in the future.
Antarctic ice sheets are a central focus of contemporary climate research due to urgent questions about their stability and reaction to global warming. Satellite technology enables researchers to study the ice sheets both through on-site fieldwork and remote sensing
Remote sensing is the acquisition of information about an physical object, object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring inform ...
, facilitating detailed analyses of ice dynamics to predict future changes in a warming world.
The INStabilities & Thresholds in ANTarctica (INSTANT) Scientific Research Programme proposes three research themes, investigating the complex interactions between the atmosphere
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...
, ocean, and solid Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
in Antarctica. Its aims include improving the understanding and predictions of these processes to aid decision makers in risk assessment, management, and mitigation related to Antarctic climate change.
The Australian-led ICECAP project utilized advanced aerogeophysical techniques to map deep subglacial basins and Channel (geography), channels that connect the ice sheet to the ocean. This mapping improves predictions of ice sheet stability, the impacts of climate change on the ice sheets, and their potential contributions to global sea level rise
The sea level has been rising from the end of the last ice age, which was around 20,000 years ago. Between 1901 and 2018, the average sea level rose by , with an increase of per year since the 1970s. This was faster than the sea level had e ...
.
Culture
Music and film
The southernmost music festival in the world, Icestock, has been held at McMurdo Station since 1989. The organizers, performers, and attendees of Icestock are all personnel working at McMurdo or nearby Scott Base. The Antarctic Film Festival is held annually between bases, with 48 stations registered to participate as of 2022. The festival is designed for short films of 5 minutes or less.
In 2011, Australian classical harpist Alice Giles became the first professional musician to perform in Antarctica. The first full-length fictional film to be shot in Antarctica was ''South of Sanity'', a 2012 low budget British horror film. An upcoming film directed by Nick Cassavetes and starring Anthony Hopkins, ''Bruno Penguin and the Staten Island Princess'', will be the first major Cinema of the United States, Hollywood production to shoot in Antarctica.
Sport
Sporting events held on Antarctica include the Antarctic Ice Marathon & 100k ultra race, Antarctica Marathon and Antarctica Cup Yacht Race. Football in Antarctica, Association football has been played since the early twentieth century, with teams representing bases or visiting ships.
Holidays
There are two principal holidays celebrated across Antarctica: Midwinter Day on the day of the southern winter solstice (June 20 or 21) and Antarctica Day on December 1, which commemorates the signing of the Antarctic Treaty in 1959.
See also
* Index of Antarctica-related articles
Notes
References
Bibliography
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Further reading
* De Pomereu, Jean; and McCahey, Daniella. ''Antarctica: A History in 100 Objects'' (Conway, 2022
online book review
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* Ivanov, Lyubomir; Ivanova, Nusha (2022). ''The World of Antarctica''. Generis Publishing. 241 pp.
External links
* of the Antarctic Treaty Secretariat (de facto government)
* High resolution map (2022) �
Reference Elevation Model of Antarctica
(Reference Elevation Model of Antarctica, REMA)
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British Antarctic Survey (BAS)
U.S. Antarctic Program Portal
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Antarctica,
Antarctic region
Articles containing video clips
Continents
Demilitarized zones
Extreme points of Earth
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Polar regions of the Earth