Where is the continental limit of the Earth's most southern continent?
60th parallel south
Title: Continental shelf
Passage: The continental margin, between the continental shelf and the abyssal plain, comprises a steep continental slope followed by the flatter continental rise. Sediment from the continent above cascades down the slope and accumulates as a pile of sediment at the base of the slope, called the continental rise. Extending as far as 500 km (310 mi) from the slope, it consists of thick sediments deposited by turbidity currents from the shelf and slope. The continental rise's gradient is intermediate between the slope and the shelf.
Title: Continental drift
Passage: Continental drift is the movement of the Earth's continents relative to each other, thus appearing to ``drift ''across the ocean bed. The speculation that continents might have 'drifted' was first put forward by Abraham Ortelius in 1596. The concept was independently and more fully developed by Alfred Wegener in 1912, but his theory was rejected by some for lack of a mechanism (though this was supplied later by Arthur Holmes). The idea of continental drift has been subsumed by the theory of plate tectonics, which explains how the continents move.
Title: Africa
Passage: Africa is the world's second largest and second most - populous continent (behind Asia in both categories). At about 30.3 million km (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area. With 1.2 billion people as of 2016, it accounts for about 16% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, the Isthmus of Suez and the Red Sea to the northeast, the Indian Ocean to the southeast and the Atlantic Ocean to the west. The continent includes Madagascar and various archipelagos. It contains 54 fully recognised sovereign states (countries), nine territories and two de facto independent states with limited or no recognition. The majority of the continent and its countries are in the Northern Hemisphere, with a substantial portion and number of countries in the Southern Hemisphere.
Title: World Park Base
Passage: World Park Base was a non-governmental year-round Antarctic base located at Cape Evans on Ross Island in the Ross Dependency. The international environmental organization Greenpeace established World Park Base in 1987 in order to press its demand for the Antarctic Treaty nations to declare all of the continent of Antarctica a World Park. This would make the entire continent off-limits to commercial exploitation and pollution, and permit only limited scientific research. Greenpeace closed down and completely dismantled the base in 1992.
Title: List of island countries
Passage: This is a list of island countries. An island is a land mass (smaller than a continent) that is surrounded by water. Many island countries are spread over an archipelago, as is the case with the Federated States of Micronesia and the Indonesia (which consists of thousands of islands). Others consist of a single island, such as Nauru, or part of an island, such as Haiti. Although Australia is designated as a continent, it is often referred to as an island, as it has no land borders. Some declared island countries are not universally recognized as politically independent, such as Northern Cyprus. Some states, such as Taiwan, officially claim to hold continental territories but are de facto limited to control over islands.
Title: Mesozoic
Passage: Compared to the vigorous convergent plate mountain-building of the late Paleozoic, Mesozoic tectonic deformation was comparatively mild. The sole major Mesozoic orogeny occurred in what is now the Arctic, creating the Innuitian orogeny, the Brooks Range, the Verkhoyansk and Cherskiy Ranges in Siberia, and the Khingan Mountains in Manchuria. This orogeny was related to the opening of the Arctic Ocean and subduction of the North China and Siberian cratons under the Pacific Ocean. Nevertheless, the era featured the dramatic rifting of the supercontinent Pangaea. Pangaea gradually split into a northern continent, Laurasia, and a southern continent, Gondwana. This created the passive continental margin that characterizes most of the Atlantic coastline (such as along the U.S. East Coast) today.
Title: Lehmann discontinuity
Passage: The Lehmann discontinuity is an abrupt increase of "P"-wave and "S"-wave velocities at the depth of , discovered by seismologist Inge Lehmann. The thickness is 220 km. It appears beneath continents, but not usually beneath oceans, and does not readily appear in globally averaged studies. Several explanations have been proposed: a lower limit to the pliable asthenosphere, a phase transition, and most plausibly, depth variation in the shear wave anisotropy. Further discussion of the Lehmann discontinuity can be found in the book "Deformation of Earth Materials" by Shun-ichirō Karato.
Title: Antarctica
Passage: Emilio Marcos Palma was the first person born south of the 60th parallel south (the continental limit according to the Antarctic Treaty), as well as the first one born on the Antarctic mainland, in 1978 at Base Esperanza, on the tip of the Antarctic Peninsula; his parents were sent there along with seven other families by the Argentine government to determine if the continent was suitable for family life. In 1984, Juan Pablo Camacho was born at the Frei Montalva Station, becoming the first Chilean born in Antarctica. Several bases are now home to families with children attending schools at the station. As of 2009, eleven children were born in Antarctica (south of the 60th parallel south): eight at the Argentine Esperanza Base and three at the Chilean Frei Montalva Station.
Title: Antarctica
Passage: Positioned asymmetrically around the South Pole and largely south of the Antarctic Circle, Antarctica is the southernmost continent and is surrounded by the Southern Ocean; alternatively, it may be considered to be surrounded by the southern Pacific, Atlantic, and Indian Oceans, or by the southern waters of the World Ocean. It covers more than 14,000,000 km2 (5,400,000 sq mi), making it the fifth-largest continent, about 1.3 times as large as Europe. The coastline measures 17,968 km (11,165 mi) and is mostly characterized by ice formations, as the following table shows:
Title: Continental crust
Passage: The continental crust consists of various layers, with a bulk composition that is intermediate to felsic. The average density of continental crust is about 2.7 g / cm, less dense than the ultramafic material that makes up the mantle, which has a density of around 3.3 g / cm. Continental crust is also less dense than oceanic crust, whose density is about 2.9 g / cm. At 25 to 70 km, continental crust is considerably thicker than oceanic crust, which has an average thickness of around 7 -- 10 km. About 40% of Earth's surface is currently occupied by continental crust. It makes up about 70% of the volume of Earth's crust.
Title: Antarctica
Passage: Antarctica (US English i/æntˈɑːrktɪkə/, UK English /ænˈtɑːktɪkə/ or /ænˈtɑːtɪkə/ or /ænˈɑːtɪkə/)[Note 1] is Earth's southernmost continent, containing the geographic South Pole. It is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 14,000,000 square kilometres (5,400,000 square miles), it is the fifth-largest continent in area after Asia, Africa, North America, and South America. For comparison, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice that averages 1.9 km (1.2 mi; 6,200 ft) in thickness, which extends to all but the northernmost reaches of the Antarctic Peninsula.
Title: Zealandia
Passage: Zealandia (/ ziːˈlændiə /), also known as the New Zealand continent or Tasmantis, is a nearly submerged mass of continental crust that sank after breaking away from Australia 60 -- 85 million years ago, having separated from Antarctica between 85 and 130 million years ago. It has variously been described as a continental fragment, a microcontinent and a continent. The name and concept for Zealandia were proposed by Bruce Luyendyk in 1995.
Title: Geological history of Earth
Passage: The Earth of the early Archean (4,000 to 2,500 million years ago) may have had a different tectonic style. During this time, the Earth's crust cooled enough that rocks and continental plates began to form. Some scientists think because the Earth was hotter, that plate tectonic activity was more vigorous than it is today, resulting in a much greater rate of recycling of crustal material. This may have prevented cratonisation and continent formation until the mantle cooled and convection slowed down. Others argue that the subcontinental lithospheric mantle is too buoyant to subduct and that the lack of Archean rocks is a function of erosion and subsequent tectonic events.
Title: Seafloor spreading
Passage: Earlier theories (e.g. by Alfred Wegener and Alexander du Toit) of continental drift postulated that continents ``ploughed ''through the sea. The idea that the seafloor itself moves (and also carries the continents with it) as it expands from a central axis was proposed by Harry Hess from Princeton University in the 1960s. The theory is well accepted now, and the phenomenon is known to be caused by convection currents in the asthenosphere, which is ductile, or plastic, and the brittle lithosphere.
Antarctica