1.
Transit of Venus
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A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and a superior planet, becoming visible against the solar disk. During a transit, Venus can be seen from Earth as a black disk moving across the face of the Sun. The duration of such transits is usually measured in hours, a transit is similar to a solar eclipse by the Moon. While the diameter of Venus is more than 3 times that of the Moon, Venus appears smaller, Transits of Venus are among the rarest of predictable astronomical phenomena. They occur in a pattern that repeats every 243 years. The periodicity is a reflection of the fact that the periods of Earth. The last transit of Venus was on 5 and 6 June 2012, and was the last Venus transit of the 21st century, the previous pair of transits were in December 1874 and December 1882. The next transits of Venus will be on 10–11 December 2117, Venus transits are historically of great scientific importance as they were used to gain the first realistic estimates of the size of the Solar System. Observations of the 1639 transit, combined with the principle of parallax, the 2012 transit provided scientists with a number of other research opportunities, particularly in the refinement of techniques to be used in the search for exoplanets. Venus, with an orbit inclined by 3. 4° relative to the Earths, although the inclination between these two orbital planes is only 3. 4°, Venus can be as far as 9. 6° from the Sun when viewed from the Earth at inferior conjunction. Since the angular diameter of the Sun is about half a degree, sequences of transits usually repeat every 243 years. After this period of time Venus and Earth have returned to nearly the same point in their respective orbits. During the Earths 243 sidereal orbital periods, which total 88,757.3 days, Venus completes 395 sidereal orbital periods of 224.701 days each and this period of time corresponds to 152 synodic periods of Venus. Prior to 1518, the pattern of transits was 8,113.5 and 121.5 years, the current pattern will continue until 2846, when it will be replaced by a pattern of 105.5,129.5 and 8 years. Thus, the 243-year cycle is relatively stable, but the number of transits, for instance, there is a series which ended in 541 BC, and the series which includes 2117 only started in AD1631. Ancient Indian, Greek, Egyptian, Babylonian and Chinese observers knew of Venus, the early Greek astronomers called Venus by two names—Hesperus the evening star and Phosphorus the morning star. Pythagoras is credited with realizing they were the same planet, there is no evidence that any of these cultures knew of the transits. Venus was important to ancient American civilizations, in particular for the Maya, who called it Noh Ek, the Great Star or Xux Ek, the Wasp Star, they embodied Venus in the form of the god Kukulkán
2.
Campbell Island, New Zealand
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Campbell Island / Motu Ihupuku is an uninhabited subantarctic island of New Zealand, and the main island of the Campbell Island group. It covers 112.68 square kilometres of the groups 113, the island is mountainous, rising to over 500 metres in the south. A long fjord, Perseverance Harbour, nearly bisects it, opening out to sea on the east coast, Campbell Island is a UNESCO World Heritage Site. Campbell Island was discovered in 1810 by Captain Frederick Hasselborough of the sealing brig Perseverance, Captain Hasselborough was drowned on 4 November 1810 in Perseverance Harbour. The island became a hunting base, and the seal population was almost totally eradicated. The first sealing boom was over by the mid-1810s, the second was a brief revival in the 1820s. The whaling boom extended here in the 1830s and ’40s, in 1874, the island was visited by a French scientific expedition intending to view the transit of Venus. Much of the topography is named after aspects of, or people connected with. In the late 19th century, the became a pastoral lease. Sheep farming was undertaken from 1896 until the lease, along with the sheep, in 1883 the American schooner Sarah W. Hunt, a whaler, was near Campbell Island. Twelve men in two small whaleboats headed for the island in terrible weather looking for seals, one of the boats disappeared, and the other boat with six men aboard managed to make it ashore. Sanford Miner, the captain of the Sarah W. Hunt, assumed all the whalers were lost, fortunately for the stranded whalers, a seal protection boat, the Kekeno, happened to arrive at the island, and rescued the castaways. The captains behavior caused an international scandal, in 1907, a group of scientists spent eight days on the island group surveying. The 1907 Sub-Antarctic Islands Scientific Expedition conducted a survey and also took botanical, zoological and geological specimens. During World War II, a station was operative at Tucker Cove at the north shore of Perseverance Harbour as part of the Cape Expedition program. After the war, the facilities were used as a station until the summer of 1957/58, when a new base was established at Beeman Cove. The new location provided improved exposure for the instruments, particularly wind recordings. The new meteorological station at Beeman Cove was operated by the New Zealand government with ten full-time staff
3.
Southern Ocean
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As such, it is regarded as the fourth-largest of the five principal oceanic divisions, smaller than the Pacific, Atlantic, and Indian Oceans but larger than the Arctic Ocean. This ocean zone is cold, northward flowing waters from the Antarctic mix with warmer subantarctic waters. By way of his voyages in the 1770s, Captain James Cook proved that waters encompassed the southern latitudes of the globe. Since then, geographers have disagreed on the Southern Oceans northern boundary or even existence, considering the part of the Pacific, Atlantic. Others regard the seasonally-fluctuating Antarctic Convergence as the natural boundary, Borders and names for oceans and seas were internationally agreed when the International Hydrographic Bureau, the precusor to the IHO, convened the First International Conference on 24 July 1919. The IHO then published these in its Limits of Oceans and Seas, Australian authorities regard the Southern Ocean as lying immediately south of Australia. Map publishers using the term Southern Ocean on their maps include Hema Maps, Southern Ocean is an obsolete name for the Pacific Ocean or South Pacific, coined by Vasco Núñez de Balboa, the first European to discover it, who approached it from the north. The South Seas is an archaic synonym. A1745 British Act of Parliament established a prize for discovering a Northwest Passage to the Western and Southern Ocean of America, authors using Southern Ocean to name the waters encircling the unknown southern polar regions used varying limits. James Cooks account of his second voyage implies New Caledonia borders it, peacocks 1795 Geographical Dictionary said it lay to the southward of America and Africa, John Payne in 1796 used 40 degrees as the northern limit, the 1827 Edinburgh Gazetteer used 50 degrees. The United Kingdoms South Australia Act 1834 described the waters forming the southern limit of the new colony of South Australia as the Southern Ocean. The Colony of Victorias Legislative Council Act of 1881 delimited part of the division of Bairnsdale as along the New South Wales boundary to the Southern ocean. The limit then followed the west coast of Tasmania southwards to the South East Cape and then went eastwards to Broughton Island, New Zealand, the northern limits of the Southern Ocean were moved southwards in the IHOs 1937 second edition of the Limits of Oceans and Seas. From this edition, much of the northern limit ceased to abut land masses. As is discussed in detail below, prior to the 2002 edition the limits of oceans explicitly excluded the seas lying within each of them. The Great Australian Bight was unnamed in the 1928 edition, and it therefore encompassed former Southern Ocean waters but was technically not inside any of the three adjacent oceans by 1937. To perform direct comparisons of current and former limits of oceans it is necessary to consider, or at least be aware of, the limits of the Atlantic, Pacific and Indian Oceans have therefore been extended South to the Antarctic Continent. The IHO readdressed the question of the Southern Ocean in a survey in 2000, of its 68 member nations,28 responded, and all responding members except Argentina agreed to redefine the ocean, reflecting the importance placed by oceanographers on ocean currents
4.
New Zealand
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New Zealand /njuːˈziːlənd/ is an island nation in the southwestern Pacific Ocean. The country geographically comprises two main landmasses—the North Island, or Te Ika-a-Māui, and the South Island, or Te Waipounamu—and around 600 smaller islands. New Zealand is situated some 1,500 kilometres east of Australia across the Tasman Sea and roughly 1,000 kilometres south of the Pacific island areas of New Caledonia, Fiji, because of its remoteness, it was one of the last lands to be settled by humans. During its long period of isolation, New Zealand developed a distinct biodiversity of animal, fungal, the countrys varied topography and its sharp mountain peaks, such as the Southern Alps, owe much to the tectonic uplift of land and volcanic eruptions. New Zealands capital city is Wellington, while its most populous city is Auckland, sometime between 1250 and 1300 CE, Polynesians settled in the islands that later were named New Zealand and developed a distinctive Māori culture. In 1642, Dutch explorer Abel Tasman became the first European to sight New Zealand, in 1840, representatives of Britain and Māori chiefs signed the Treaty of Waitangi, which declared British sovereignty over the islands. In 1841, New Zealand became a colony within the British Empire, today, the majority of New Zealands population of 4.7 million is of European descent, the indigenous Māori are the largest minority, followed by Asians and Pacific Islanders. Reflecting this, New Zealands culture is derived from Māori and early British settlers. The official languages are English, Māori and New Zealand Sign Language, New Zealand is a developed country and ranks highly in international comparisons of national performance, such as health, education, economic freedom and quality of life. Since the 1980s, New Zealand has transformed from an agrarian, Queen Elizabeth II is the countrys head of state and is represented by a governor-general. In addition, New Zealand is organised into 11 regional councils and 67 territorial authorities for local government purposes, the Realm of New Zealand also includes Tokelau, the Cook Islands and Niue, and the Ross Dependency, which is New Zealands territorial claim in Antarctica. New Zealand is a member of the United Nations, Commonwealth of Nations, ANZUS, Organisation for Economic Co-operation and Development, Pacific Islands Forum, and Asia-Pacific Economic Cooperation. Dutch explorer Abel Tasman sighted New Zealand in 1642 and called it Staten Landt, in 1645, Dutch cartographers renamed the land Nova Zeelandia after the Dutch province of Zeeland. British explorer James Cook subsequently anglicised the name to New Zealand, Aotearoa is the current Māori name for New Zealand. It is unknown whether Māori had a name for the country before the arrival of Europeans. Māori had several names for the two main islands, including Te Ika-a-Māui for the North Island and Te Waipounamu or Te Waka o Aoraki for the South Island. Early European maps labelled the islands North, Middle and South, in 1830, maps began to use North and South to distinguish the two largest islands and by 1907, this was the accepted norm. The New Zealand Geographic Board discovered in 2009 that the names of the North Island and South Island had never been formalised and this set the names as North Island or Te Ika-a-Māui, and South Island or Te Waipounamu
5.
Natural history
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Natural history is the research and study of organisms including animals, fungi and plants in their environment, leaning more towards observational than experimental methods of study. It encompasses scientific research but is not limited to it, with articles nowadays more often published in magazines than in academic journals. Grouped among the sciences, natural history is the systematic study of any category of natural objects or organisms. That is a broad designation in a world filled with many narrowly focused disciplines. For example, geobiology has a strong multi-disciplinary nature combining scientists, a person who studies natural history is known as a naturalist or natural historian. The English term natural history is a translation of the Latin historia naturalis and its meaning has narrowed progressively with time, while the meaning of the related term nature has widened. In antiquity, it covered essentially anything connected with nature or which used materials drawn from nature. For example, Pliny the Elders encyclopedia of this title, published circa 77 to 79 AD, covers astronomy, geography, man and his technology, medicine and superstition as well as animals and plants. Medieval European academics considered knowledge to have two divisions, the humanities and divinity, with science studied largely through texts rather than observation or experiment. In modern terms, natural philosophy roughly corresponded to modern physics and chemistry, natural history had been encouraged by practical motives, such as Linnaeus aspiration to improve the economic condition of Sweden. Similarly, the Industrial Revolution prompted the development of geology to help find useful mineral deposits, the astronomer, William Herschel was also a natural historian. Instead of working with plants or minerals he worked with the stars and he spent his time building telescopes to see the stars and the rest of the time watching the stars. In the beginning, he believed there to be a known as a nebulae. Herschel can be considered a natural historian because he observed the natural world, in the process he made charts of all the stars and kept records of all that he saw. S. Wilcove and T. Eisner, The close observation of organisms—their origins, their evolution, their behavior and it encompasses changes in internal states insofar as they pertain to what organisms do. Some definitions go further, focusing on observation of organisms in their environment. Bartholomew, A student of history, or a naturalist, studies the world by observing plants. A common thread in many definitions of natural history is the inclusion of a component, as seen in a recent definition by H. W. Greene
6.
Henri Filhol
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Henri Filhol was a French medical doctor, malacologist and naturalist born in Toulouse. He was the son of Édouard Filhol, curator of the Museum of Toulouse, after receiving his early education in Toulouse, he moved to Paris, where he obtained doctorates in medicine and science. In 1879 he was appointed professor of zoology at the Faculty of Toulouse, from 1894 to 1902 he occupied the chair of comparative animal anatomy at the Muséum national dHistoire naturelle in Paris. In 1897 he became a member of the Académie des sciences, in the field of paleontology, he performed important studies of fossilized mammals in the phosphorites in Quercy. He served as the doctor and naturalist on the French 1874 Transit of Venus expedition to Campbell Island, New Zealand, with a peak on the island, Filhol Peak. In 1883 with Alphonse Milne-Edwards, Léon Vaillant, Edmond Perrier and others, he embarked on a scientific journey aboard the Talisman
7.
Marseille
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Marseille, also known as Marseilles in English, is a city in France. Known to the ancient Greeks and Romans as Massalia, Marseille was the most important trading centre in the region, Marseille is now Frances largest city on the Mediterranean coast and the largest port for commerce, freight and cruise ships. The city was European Capital of Culture, together with Košice, Slovakia and it hosted the European Football Championship in 2016, and will be the European Capital of Sport in 2017. The city is home to campuses of Aix-Marseille University and part of one of the largest metropolitan conurbations in France. Marseille is the second largest city in France after Paris and the centre of the third largest metropolitan area in France after Paris, further east still are the Sainte-Baume, the city of Toulon and the French Riviera. To the north of Marseille, beyond the low Garlaban and Etoile mountain ranges, is the 1,011 m Mont Sainte Victoire. To the west of Marseille is the artists colony of lEstaque, further west are the Côte Bleue, the Gulf of Lion. The airport lies to the north west of the city at Marignane on the Étang de Berre, the citys main thoroughfare stretches eastward from the Old Port to the Réformés quarter. Two large forts flank the entrance to the Old Port—Fort Saint-Nicolas on the south side and Fort Saint-Jean on the north. Further out in the Bay of Marseille is the Frioul archipelago which comprises four islands, one of which, If, is the location of Château dIf, the main commercial centre of the city intersects with the Canebière at rue St Ferréol and the Centre Bourse. To the south east of central Marseille in the 6th arrondissement are the Prefecture and the fountain of Place Castellane. To the south west are the hills of the 7th arrondissement, the railway station—Gare de Marseille Saint-Charles—is north of the Centre Bourse in the 1st arrondissement, it is linked by the Boulevard dAthènes to the Canebière. Marseille has a Mediterranean climate with mild, humid winters and warm to hot, december, January, and February are the coldest months, averaging temperatures of around 12 °C during the day and 4 °C at night. Marseille is officially the sunniest major city in France with over 2,900 hours of sunshine while the average sunshine in France is around 1,950 hours, less frequent is the Sirocco, a hot, sand-bearing wind, coming from the Sahara Desert. Snowfalls are infrequent, over 50% of years do not experience a single snowfall, Massalia, whose name was probably adapted from an existing language related to Ligurian, was the first Greek settlement in France. It was established within modern Marseille around 600 BC by colonists coming from Phocaea on the Aegean coast of Asia Minor. The connection between Massalia and the Phoceans is mentioned in Thucydidess Peloponnesian War, he notes that the Phocaean project was opposed by the Carthaginians, the founding of Massalia has also been recorded as a legend. Protis was invited inland to a banquet held by the chief of the local Ligurian tribe for suitors seeking the hand of his daughter Gyptis in marriage, at the end of the banquet, Gyptis presented the ceremonial cup of wine to Protis, indicating her unequivocal choice
8.
Jetty
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A jetty is a structure that projects from the land out into water. Often, jetty refers to a walkway accessing the centre of an enclosed waterbody, the term is derived from the French word jetée, thrown, and signifies something thrown out. The nes jetties at Dunkirk were founded in the beach, by the aid of compressed air. Below low water of spring tides, and their solid masonry portion, on a foundation was raised 50 feet. Above low water of neap tides, hence a bar is produced that diminishes the available depth in the approach channel. By carrying out a solid jetty over the bar, however on each side of the outlet, the currents are concentrated in the channel across the bar. Where a river is narrow near its mouth, has a generally feeble discharge and a tidal range. The channel, also, beyond the outlet of the river Nervion into the Bay of Biscay has been regulated by jetties, and by extending the south-west jetty out for nearly 0
9.
Corona
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A corona is an aura of plasma that surrounds the sun and other stars. The Suns corona extends millions of kilometres into space and is most easily seen during a solar eclipse. The word corona is a Latin word meaning crown, from the Ancient Greek κορώνη, the high temperature of the Suns corona gives it unusual spectral features, which led some in the 19th century to suggest that it contained a previously unknown element, coronium. Instead, these features have since been explained by highly ionized iron. Bengt Edlén, following the work of Grotrian, first identified the coronal spectral lines in 1940 as transitions from low-lying metastable levels of the configuration of highly ionised metals. These high stages of ionisation indicate a temperature in excess of 1,000,000 kelvins. Light from the corona comes from three sources, from the same volume of space. The suns corona is much hotter than the surface of the Sun. The corona is 10−12 times as dense as the photosphere, the corona is separated from the photosphere by the relatively shallow chromosphere. The exact mechanism by which the corona is heated is still the subject of some debate, the outer edges of the Suns corona are constantly being transported away due to open magnetic flux and hence generating the solar wind. The corona is not always evenly distributed across the surface of the sun, during periods of quiet, the corona is more or less confined to the equatorial regions, with coronal holes covering the polar regions. However, during the Suns active periods, the corona is evenly distributed over the equatorial and polar regions, the solar cycle spans approximately 11 years, from solar minimum to the following minimum. Associated with sunspots are coronal loops, loops of magnetic flux, the magnetic flux pushes the hotter photosphere aside, exposing the cooler plasma below, thus creating the relatively dark sun spots. The astronomers usually distinguish several regions, as described below, active regions are ensembles of loop structures connecting points of opposite magnetic polarity in the photosphere, the so-called coronal loops. They generally distribute in two zones of activity, which are parallel to the solar equator, the average temperature is between two and four million kelvins, while the density goes from 109 to 1010 particle per cm3. If flares are very violent, they can also perturb the photosphere, on the contrary, quiescent prominences are large, cool dense structures which are observed as dark, snake-like Hα ribbons on the solar disc. Their temperature is about 5000–8000 K, and so they are considered as chromospheric features. In 2013, images from the High Resolution Coronal Imager revealed never-before-seen magnetic braids of plasma within the layers of these active regions
10.
New Caledonia
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New Caledonia is a special collectivity of France located in the southwest Pacific Ocean,1,210 km east of Australia and 16,136 km east of Metropolitan France. The Chesterfield Islands are in the Coral Sea, locals refer to Grande Terre as Le Caillou. New Caledonia has an area of 18,576 km2. Its population of 268,767 consists of a mix of Kanak people, people of European descent, Polynesian people, the capital of the territory is Nouméa. The earliest traces of human presence in New Caledonia date back to the Lapita period, the Lapita were highly skilled navigators and agriculturists with influence over a large area of the Pacific. British explorer Captain James Cook was the first European to sight New Caledonia, on 4 September 1774 and he named it New Caledonia, as the northeast of the island reminded him of Scotland. The west coast of Grande Terre was approached by Jean-François de Galaup, comte de Lapérouse in 1788, shortly before his disappearance, from then until 1840, only a few sporadic contacts with the archipelago were recorded. Contacts became more frequent after 1840, because of the interest in sandalwood from New Caledonia, the trade ceased at the start of the 20th century. The victims of this trade were called Kanakas, like all the Oceanian people, the first missionaries from the London Missionary Society and the Marist Brothers arrived in the 1840s. In 1849, the crew of the American ship Cutter was killed, cannibalism was widespread throughout New Caledonia. On 24 September 1853, under orders from Napoleon III, Admiral Febvrier Despointes took formal possession of New Caledonia, a few dozen free settlers settled on the west coast in the following years. New Caledonia became a colony, and from the 1860s until the end of the transportations in 1897, about 22,000 criminals. Among the convicts were many Communards arrested after the failed Paris Commune, including Henri de Rochefort, between 1873 and 1876,4,200 political prisoners were relegated in New Caledonia. Only 40 of them settled in the colony, the rest returned to France after being granted amnesty in 1879 and 1880. In 1864, nickel was discovered on the banks of the Diahot River and with the establishment of the Société Le Nickel in 1876, mining began in earnest. The French imported labourers to work in the mines, first from neighbouring islands, then from Japan, the Dutch East Indies, the French government also attempted to encourage European immigration, without much success. The indigenous population was excluded from the French economy, even as workers in the mines, and they were ultimately confined to reservations. This sparked a violent reaction in 1878 as High Chief Atal of La Foa managed to unite many of the central tribes, the Europeans brought new diseases such as smallpox and measles
11.
Nagasaki
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Nagasaki is the capital and the largest city of Nagasaki Prefecture on the island of Kyushu in Japan. Part of Nagasaki was home to a major Imperial Japanese Navy base during the First Sino-Japanese War, during World War II, the American atomic bombings of Hiroshima and Nagasaki made Nagasaki the second and, to date, last city in the world to experience a nuclear attack. As of 1 January 2009, the city has an population of 446,007. The total area is 406.35 km², a small fishing village set in a secluded harbor, Nagasaki had little historical significance until contact with Portuguese explorers in 1543. An early visitor was Fernão Mendes Pinto, who came on a Portuguese ship which landed nearby in Tanegashima and his followers who remained behind converted a number of daimyōs. The most notable among them was Ōmura Sumitada, the little harbor village quickly grew into a diverse port city, and Portuguese products imported through Nagasaki were assimilated into popular Japanese culture. The Portuguese also brought them many goods from China. Thus, for a period after 1580, the city of Nagasaki was a Jesuit colony, under their administrative. It was administered by the captain of the Portuguese black ship, the highest representative of the Portuguese Crown and it became a refuge for Christians escaping maltreatment in other regions of Japan. In 1587, however, Toyotomi Hideyoshis campaign to unify the country arrived in Kyūshū, however, the expulsion order went largely unenforced, and the fact remained that most of Nagasakis population remained openly practicing Catholic. In 1596, the Spanish ship San Felipe was wrecked off the coast of Shikoku, in response, Hideyoshi ordered the crucifixions of twenty-six Catholics in Nagasaki on February 5 of that year. Portuguese traders were not ostracized, however, and so the city continued to thrive, in 1602, Augustinian missionaries also arrived in Japan, and when Tokugawa Ieyasu took power in 1603, Catholicism was still tolerated. Many Catholic daimyōs had been allies at the Battle of Sekigahara. Once Osaka Castle had been taken and Toyotomi Hideyoshis offspring killed, though, in addition, the Dutch and English presence allowed trade without religious strings attached. Thus, in 1614, Catholicism was officially banned and all missionaries ordered to leave, most Catholic daimyo apostatized, and forced their subjects to do so, although a few would not renounce the religion and left the country for Macau, Luzon and Japantowns in Southeast Asia. A brutal campaign of persecution followed, with thousands of converts across Kyūshū and other parts of Japan killed, tortured, catholicisms last gasp as an open religion and the last major military action in Japan until the Meiji Restoration was the Shimabara Rebellion of 1637. Consequently, in Tokugawa society the word Shimabara solidified the connection between Christianity and disloyalty, constantly used again and again in Tokugawa propaganda, the Shimabara Rebellion also convinced many policy-makers that foreign influences were more trouble than they were worth, leading to the national isolation policy. The Great Fire of Nagasaki destroyed much of the city in 1663, including the Mazu shrine at the Kofukuji Temple patronized by the Chinese sailors, in 1720 the ban on Dutch books was lifted, causing hundreds of scholars to flood into Nagasaki to study European science and art
12.
Subantarctic
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The Subantarctic is a region in the southern hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° – 60° south of the Equator, the subantarctic region includes many islands in the southern parts of the Indian Ocean, Atlantic Ocean and Pacific Ocean, especially those situated north of the Antarctic Convergence. Subantarctic glaciers are, by definition, located on islands within the subantarctic region, all glaciers located on the continent of Antarctica are by definition considered to be Antarctic glaciers. The subantarctic region comprises two zones and three distinct fronts. The northernmost boundary of the region is the rather ill-defined Subtropical Front. To the south of the STF is a zone, the Subantarctic Zone. South of the SAZ is the Subantarctic Front, South of the SAF is another marine zone, called the Polar Frontal Zone. The SAZ and the PFZ together form the subantarctic region, the southernmost boundary of the PFZ is the Antarctic Convergence, located approximately 200 kilometers south of the Antarctic Polar Front. The ACC is the most important ocean current in the Southern Ocean, flowing eastward through the southern portions of the Atlantic, Indian, and Pacific Oceans, the ACC links these three otherwise separate oceanic basins. Extending from the sea surface to depths of 2000–4000 meters, and with a width of as great as 2000 kilometers, the ACC carries up to 150 Sverdrups, equivalent to 150 times the volume of water flowing in all the worlds rivers. The ACC and the global thermohaline circulation strongly influence regional and global climate as well as underwater biodiversity, the halothermal circulation is that portion of the global ocean circulation that is driven by global density gradients created by surface heat and evaporation. Several distinct water masses converge in the vicinity of the APF or Antarctic Convergence. This convergence creates an environment, noted for its very high marine productivity. Because of this, all lands and waters situated south of the Antarctic Convergence are considered to belong to the Antarctic from a climatological, biological and hydrological standpoint. However, the text of the Antarctic Treaty, article VI states, therefore, Antarctica is defined from a political standpoint as all land and ice shelves south of 60°S latitude. Because they are located far to the north of the Antarctic Convergence and have a temperate climate. The geography of islands is characterized by tundra, with some trees on Snares. These islands are all located near the Antarctic Convergence and are considered to be subantarctic islands
