Tasmantid Seamount Chain
The Tasmantid Seamount Chain (alternatively Tasmantid Seamounts, Tasman Seamounts, Tasman Seamount Chain, Tasmantide Volcanoes or the Tasmantids) is a long chain of seamounts in the South Pacific Ocean. The chain consists of over 16 extinct volcanic peaks, many rising more than from the seabed. It is one of the two parallel seamount chains alongside the East Coast of Australia; the Lord Howe and Tasmantid seamount chains both run north–south through parts of the Coral Sea and Tasman Sea. These chains have longitudes of approximately 159°E and 156°E respectively. Like its neighbour, the Tasmantid Seamount Chain has resulted from the Indo-Australian Plate moving northward over a stationary hotspot.W. J. Morgan and J. P. Morgan. Plate velocities in hotspot reference frame: electronic supplement'. It ranges in age from about 56 to 7 million years old. Features The Tasmantid Seamount Chain includes the following named seamounts: There is an unnamed seamount between Stra ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tasmanian Seamounts
The Tasmanian Seamounts (also ''Tasman Seamounts'' and ''Tasmania Seamounts'') are a group of seamounts (Submarine volcano, underwater volcanoes) located off the southern tip of Tasmania. The seamounts were created more than 55 million years ago by the Tasman Hotspot (geology), hotspot. The seamounts are ecologically important, and harbor a lush marine ecosystem, but are threatened by overfishing. For this reason, part of the Tasmanian Seamounts were incorporated into a marine reserve in 1999. Geology The Tasmanian Seamounts were created by the Tasman Hotspot (geology), hotspot, a long mantle plume that is currently the active center of Mount Erebus in Antarctica. The seamounts, created roughly 55 million years ago, are between deep, across, and tall. Ecology The Tasmanian Seamounts are an important feature of the south Tasmanian marine environment. While oceans generally contain few nutrients, the presence of seamounts increases the flowing speed of the water curren ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Extinct Volcano
A volcano is commonly defined as a vent or fissure in the Crust (geology), crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where list of tectonic plates, tectonic plates are divergent boundary, diverging or convergent boundary, converging, and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes resulting from divergent tectonic activity are usually non-explosive whereas those resulting from convergent tectonic activity cause violent eruptions."Mid-ocean ridge tectonics, volcanism and geomorphology." Geology 26, no. 455 (2001): 458. https://macdonald.faculty.geol.ucsb.edu/papers/Macd ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Fraser Island
K'gari ( , ), also known by its former name Fraser Island, is a World Heritage-listed sand island along the south-eastern coast in the Wide Bay–Burnett region of Queensland, Australia. The island lies approximately north of the state capital, Brisbane, and is within the Fraser Coast Region local council area. The world heritage listing includes the island, its surrounding waters and parts of the nearby mainland which make up the Great Sandy National Park. In the , the island had a population of 152. Up to 500,000 people visit the island each year. The island is part of the traditional lands of the Butchulla people, under the traditional name of "K'gari". European settlers who arrived in 1847 named the island "Fraser Island" after Captain James Fraser, master of ''Stirling Castle'', who was shipwrecked and died on the island in early August 1836. On 7 June 2023, the island was officially renamed K'gari by the state government. History Geological history The island was f ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Megaannum
A year is a unit of time based on how long it takes the Earth to orbit the Sun. In scientific use, the tropical year (approximately 365 solar days, 5 hours, 48 minutes, 45 seconds) and the sidereal year (about 20 minutes longer) are more exact. The modern calendar year, as reckoned according to the Gregorian calendar, approximates the tropical year by using a system of leap years. The term 'year' is also used to indicate other periods of roughly similar duration, such as the lunar year (a roughly 354-day cycle of twelve of the Moon's phasessee lunar calendar), as well as periods loosely associated with the calendar or astronomical year, such as the seasonal year, the fiscal year, the academic year, etc. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by changes in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are gener ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Gascoyne Seamount
Gascoyne Seamount, also called Gascoyne Guyot or Gascoyne Tablemount, is a guyot in the Tasman Sea of the South Pacific Ocean. Geography Located east of the Australian coastal town of Bermagui, Gascoyne Seamount is the southernmost and youngest significant seamount of the Tasmantid Seamount Chain. This is an underwater mountain range extending some to the north. The Tasmantid Seamount Chain has resulted from the Indo-Australian Plate moving northward over a stationary hotspot. Geology The seamount is about 7 million years old. It incorporates a tropical to subtropical, very shallow water calcareous algal/encrusting foraminiferid biota, suggesting deposition in water deep. Age diagnostic forms have not been recovered. Gascoyne Seamount is named after HMAS ''Gascoyne'', one of two ships in the Royal Australian Navy The Royal Australian Navy (RAN) is the navy, naval branch of the Australian Defence Force (ADF). The professional head of the RAN is Chief of Navy (Australi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Argon–argon Dating
Argon–argon (or 40Ar/39Ar) dating is a radiometric dating method invented to supersede Potassium-argon dating, potassiumargon (K/Ar) dating in accuracy. The older method required splitting samples into two for separate potassium and argon measurements, while the newer method requires only one rock fragment or mineral grain and uses a single measurement of isotopes of argon, argon isotopes. 40Ar/39Ar dating relies on neutron irradiation from a nuclear reactor to convert a stable form of potassium (39K) into the radioactive 39Ar. As long as a standard of known age is co-irradiated with unknown samples, it is possible to use a single measurement of argon isotopes to calculate the 40K/40Ar* ratio, and thus to calculate the age of the unknown sample. 40Ar* refers to the radiogenic 40Ar, i.e. the 40Ar produced from radioactive decay of 40K. 40Ar* does not include atmospheric argon adsorbed to the surface or inherited through diffusion and its calculated value is derived from measuring t ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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K–Ar Dating
Potassium–argon dating, abbreviated K–Ar dating, is a radiometric dating method used in geochronology and archaeology. It is based on the measurement of the product of the radioactive decay of an isotope of potassium (K) into argon (Ar). Potassium is a common element in many materials, such as feldspars, micas, clay minerals, tephra, and evaporites. In these materials, the decay product can escape the liquid (molten) rock but starts to accumulate when the rock solidifies (Recrystallization (geology), recrystallizes). The amount of argon sublimation that occurs is a function of the sample's purity, the composition of the mother material, and several other factors. These factors introduce error limits on the upper and lower bounds of dating so that the final determination of age is reliant on the environmental factors during formation, melting, and exposure to decreased pressure or open air. Time since recrystallization is calculated by measuring the ratio of the amount of accum ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tasmantid Hotspot
The Tasmantid hotspot is a volcanic hotspot located in the South Pacific Ocean. The northward movement of the Indo-Australian Plate over the last 60 million years coupled with volcanism of the Tasmantid hotspot has resulted in a north–south line of submarine volcanoes called the Tasmantid Seamount Chain. This includes over 10 seamounts, the youngest of which is the seven million year old Gascoyne Seamount. The Tasmantid hotspot is now south of Gascoyne Seamount and is defined by a prominent zone of seismic activity. Due to plate tectonics the hotspot was under different parts of the seabed in the past. It was initially centred under what is now the southern Coral Sea about 60 million years ago somewhere close to where the present Louisiade Plateau is located, so it has been suggested that the Louisiade Plateau might be a large igneous province created by the hotspot. At the southern boundary of the plateau are volcanic rocks that appear in age and type to be able ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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156th Meridian East
The meridian 156° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Pacific Ocean, Australasia, the Southern Ocean, and Antarctica to the South Pole. The 156th meridian east forms a great circle with the 24th meridian west. From Pole to Pole Starting at the North Pole and heading south to the South Pole, the 156th meridian east passes through: : See also *155th meridian east The meridian 155° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Pacific Ocean, Australasia, the Southern Ocean, and Antarctica to the South Pole. The 155th meridian east forms a gr ... * 157th meridian east {{geographical coordinates, state=collapsed e156 meridian east ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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159th Meridian East
The meridian 159° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Pacific Ocean, Australasia, the Southern Ocean, and Antarctica to the South Pole. The 159th meridian east forms a great circle with the 21st meridian west. From Pole to Pole Starting at the North Pole and heading south to the South Pole, the 159th meridian east passes through: : See also * 158th meridian east *160th meridian east The meridian 160° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Asia, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole. The 160th meridian east forms a great circle wit ... {{geographical coordinates, state=collapsed e159 meridian east ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Longitude
Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (λ). Meridians are imaginary semicircular lines running from pole to pole that connect points with the same longitude. The prime meridian defines 0° longitude; by convention the International Reference Meridian for the Earth passes near the Royal Observatory in Greenwich, south-east London on the island of Great Britain. Positive longitudes are east of the prime meridian, and negative ones are west. Because of the Earth's rotation, there is a close connection between longitude and time measurement. Scientifically precise local time varies with longitude: a difference of 15° longitude corresponds to a one-hour difference in local time, due to the differing position in relation to the Sun. Comparing local time to an absol ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |