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Stokes Magnetic Anomaly
The Stokes Magnetic Anomaly (also known as the Stokes Magnetic Anomaly System, SMAS, New Zealand Junction Magnetic Anomaly, JMA, great Nelson magnetic disturbance, Junction Anomaly, Campbell Magnetic Anomaly System, CMAS) is a magnetic anomaly on the Earth's surface that extends from New Caledonia to the Chatham Rise with complexity consistent with the theory of plate tectonics. History It is named after Captain (later Admiral) John Lort Stokes by G. C. Farr in 1916 as he described it first although such naming has proved controversial, hence many of the alternative names. The magnetic declinations were observed by Captain Stokes when captaining HMS Acheron and Commander (later Admiral) Byron Drury in HMS Pandora between 1851 and 1853. Geology The Stokes Magnetic Anomaly has been characterised for over and was essential for understanding the geology of Zealandia as a mainly underwater continent. It extends from south of New Caledonia to almost the eastern edge of the Camp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Anomaly
In geophysics, a magnetic anomaly is a local variation in the Earth's magnetic field resulting from variations in the chemistry or magnetism of the rocks. Mapping of variation over an area is valuable in detecting structures obscured by overlying material. The magnetic variation (geomagnetic reversals) in successive bands of ocean floor parallel with mid-ocean ridges was important evidence for seafloor spreading, a concept central to the theory of plate tectonics. Measurement Magnetic anomalies are generally a small fraction of the magnetic field. The total field ranges from 25,000 to 65,000 nanoteslas (nT). To measure anomalies, magnetometers need a sensitivity of 10 nT or less. There are three main types of magnetometer used to measure magnetic anomalies: # The fluxgate magnetometer was developed during World War II to detect submarines. It measures the component along a particular axis of the sensor, so it needs to be oriented. On land, it is often oriented vertically, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Island
The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, and to the south and east by the Pacific Ocean. The South Island covers , making it the world's 12th-largest island. At low altitude, it has an oceanic climate. The South Island is shaped by the Southern Alps which run along it from north to south. They include New Zealand's highest peak, Aoraki / Mount Cook at . The high Kaikōura Ranges lie to the northeast. The east side of the island is home to the Canterbury Plains while the West Coast is famous for its rough coastlines such as Fiordland, a very high proportion of native bush and national parks, and the Fox and Franz Josef Glaciers. The main centres are Christchurch and Dunedin. The economy relies on agriculture and fishing, tourism, and general manufacturing and services. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geography Of New Caledonia
The geography of New Caledonia (''Nouvelle-Calédonie''), an overseas collectivity of France located in the subregion of Melanesia, makes the continental island group unique in the southwest Pacific. Among other things, the island chain has played a role in preserving unique biological lineages from the Mesozoic. It served as a waystation in the expansion of the predecessors of the Polynesians, the Lapita culture. Under the Free French it was a vital naval base for Allied Forces during the War in the Pacific. The archipelago is located east of Australia, north of New Zealand, south of the Equator, and just west of Fiji and Vanuatu. New Caledonia comprises a main island, Grande Terre, the Loyalty Islands, and several smaller islands. Approximately half the size of Taiwan, the group has a land area of . The islands have a coastline of . New Caledonia claims an exclusive fishing zone to a distance of and a territorial sea of from shore. New Caledonia is one of the northernmost pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of New Zealand
The geology of New Zealand is noted for its volcanic activity, earthquakes and geothermal areas because of its position on the boundary of the Australian Plate and Pacific Plates. New Zealand is part of Zealandia, a microcontinent nearly half the size of Australia that broke away from the Gondwanan supercontinent about 83 million years ago. New Zealand's early separation from other landmasses and subsequent evolution have created a unique fossil record and modern ecology. New Zealand's geology can be simplified into three phases. First the basement rocks of New Zealand formed. These rocks were once part of the super-continent of Gondwana, along with South America, Africa, Madagascar, India, Antarctica and Australia. The rocks that now form the, mostly submerged, continent of Zealandia were then nestled between Eastern Australia and Western Antarctica. Secondly New Zealand drifted away from Gondwana and many sedimentary basins formed, which later became the sedimentary rocks cove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continents
A continent is any of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continents. Ordered from largest in area to smallest, these seven regions are: Asia, Africa, North America, South America, Antarctica, Europe, and Australia. "Most people recognize seven continents—Asia, Africa, North America, South America, Antarctica, Europe, and Australia, from largest to smallest—although sometimes Asia and Europe are considered a single continent, Eurasia." Variations with fewer continents may merge some of these, for example America, Eurasia, or Afro-Eurasia are sometimes treated as single continents, which can bring the total number as low as four. Zealandia, a largely submerged mass of continental crust, has also been described as a continent. Oceanic islands are frequently grouped with a nearby continent to divide all the world's land into geographical regions. Under this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Fragments
Continental may refer to: Places * Continent, the major landmasses of Earth * Continental, Arizona, a small community in Pima County, Arizona, US * Continental, Ohio, a small town in Putnam County, US Arts and entertainment * ''Continental'' (album), an album by Saint Etienne * Continental (card game), a rummy-style card game * ''Continental'' (film), a 2013 film * Continental Singers, a Christian music organization Companies * Continental AG, a German automotive parts and technologies manufacturer * Continental Airlines, a former American airline * Continental Electronics, an American radio transmitter manufacturer * Continental Films, a German-controlled French film company during the Nazi occupation of France * Continental Illinois, a defunct large bank * Continental Mortgage and Loan Company (later known as Continental, Inc.), the former name of HomeStreet Bank * Continental Motors, Inc., a Chinese manufacturer of aircraft engines * Continental Records, a former American re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Anomalies
In geophysics, a magnetic anomaly is a local variation in the Earth's magnetic field resulting from variations in the chemistry or magnetism of the rocks. Mapping of variation over an area is valuable in detecting structures obscured by overlying material. The magnetic variation (geomagnetic reversals) in successive bands of ocean floor parallel with mid-ocean ridges was important evidence for seafloor spreading, a concept central to the theory of plate tectonics. Measurement Magnetic anomalies are generally a small fraction of the magnetic field. The total field ranges from 25,000 to 65,000 nanoteslas (nT). To measure anomalies, magnetometers need a sensitivity of 10 nT or less. There are three main types of magnetometer used to measure magnetic anomalies: # The fluxgate magnetometer was developed during World War II to detect submarines. It measures the component along a particular axis of the sensor, so it needs to be oriented. On land, it is often oriented vertically, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of . Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of . Antarctica is, on average, the coldest, driest, and windiest of the continents, and it has the highest average elevation. It is mainly a polar desert, with annual precipitation of over along the coast and far less inland. About 70% of the world's freshwater reserves are frozen in Antarctica, which, if melted, would raise global sea levels by almost . Antarctica holds the record for the lowest measured temperature on Earth, . The coastal regions can reach temperatures over in summer. Native species of animals include mites, nematodes, penguins, seals and tardigrades. Where vegetation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marie Byrd Land
Marie Byrd Land (MBL) is an unclaimed region of Antarctica. With an area of , it is the largest unclaimed territory on Earth. It was named after the wife of American naval officer Richard E. Byrd, who explored the region in the early 20th century. The territory lies in West Antarctica, east of the Ross Ice Shelf and the Ross Sea and south of the Pacific Ocean portion of the Southern Ocean, extending eastward approximately to a line between the head of the Ross Ice Shelf and Eights Coast. It stretches between 158°W and 103°24'W. The inclusion of the area between the Rockefeller Plateau and Eights Coast is based upon Byrd's exploration. Overview Because of its remoteness, even by Antarctic standards, most of Marie Byrd Land (the portion east of 150°W) has not been claimed by any sovereign state. It is by far the largest single unclaimed territory on Earth, with an area of (including Eights Coast, immediately east of Marie Byrd Land). In 1939, United States President Frankl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lord Howe Rise
The Lord Howe Rise is a deep sea plateau which extends from south west of New Caledonia to the Challenger Plateau, west of New Zealand in the south west of the Pacific Ocean. To its west is the Tasman Basin and to the east is the New Caledonia Basin. Lord Howe Rise has a total area of about 1,500,000 square km, and generally lies about 750 to 1,200 metres under water. It is part of Zealandia, a much larger continent that is now mostly submerged, and so is composed of continental crust. Formation The Lord Howe Rise was formed by seafloor spreading which also resulted in the creation of the Tasman Sea. It was rifted away from Eastern Australia by a mid-ocean ridge that was active from 80 to 60 million years ago, and now lies 800 kilometres offshore from mainland Australia. The Lord Howe Rise contains a line of seamounts called the Lord Howe Seamount Chain which formed during the Miocene period when this part of Zealandia existed over the Lord Howe hotspot. Lord Howe was th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Challenger Plateau
The Challenger Plateau is a large submarine plateau west of New Zealand and south of the Lord Howe Rise. It has an approximate diameter of and an area of about . The water depth over the plateau varies between to and is covered by up to of sedimentary rocks of Upper Cretaceous to recent in age. The plateau originated in the Gondwanan breakup and is one of the five major submerged parts of Zealandia, a largely submerged continent A continent is any of several large landmasses. Generally identified by convention rather than any strict criteria, up to seven geographical regions are commonly regarded as continents. Ordered from largest in area to smallest, these seven .... References Geography of the New Zealand seabed Plateaus of the Pacific Ocean Zealandia {{marine-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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