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This page is about the geologic term. For other uses, see Hotspot. HotSpot is the primary Java Virtual Machine for desktops and servers produced by Sun Microsystems.

In geology, a hotspot is a location on the Earth's surface that has experienced active volcanism for a long period of time. Geology (from Greek γη gê, "earth" and λόγος Logos, "speech" lit Plate tectonics and hotspots Divergent plate boundaries At the J. Tuzo Wilson came up with the idea in 1963 that volcanic chains like the Hawaiian Islands result from the slow movement of a tectonic plate across a "fixed" hot spot deep beneath the surface of the planet. John Tuzo Wilson PhD, CC, OBE, DSc, FRS, FRSC, FRSE ( October 24, 1908 &ndash The Hawaiian Islands, once known as the Sandwich Islands, form an Archipelago of 19 Islands and Atolls numerous smaller Plate tectonics (from Greek τέκτων tektōn "builder" or "mason" describes the large scale motions of Earth 's Lithosphere Hotspots are thought to be caused by a narrow stream of hot mantle convecting up from the Earth's core-mantle boundary called a mantle plume,[1] although some geologists prefer upper-mantle convection as a cause. In Physics, heat, symbolized by Q, is Energy transferred from one body or system to another due to a difference in Temperature The mantle is a part of an Astronomical object. The interior of the Earth, similar to the other Terrestrial planets, is Chemically divided Convection in the most general terms refers to the movement of molecules within Fluids (i The core-mantle boundary (or CMB in the parlance of solid earth geophysicists lies between the Earth's Silicate mantle and its liquid Iron - Nickel A mantle plume is an upwelling of abnormally hot rock within the Earth's mantle. [2][3] This in turn has re-raised the antipodal pair impact hypothesis, the idea that pairs of opposite hotspots may result from the impact of a large meteor. [4] Geologists have identified some 40–50 such hotspots around the globe, with Hawaii, Réunion, Yellowstone, Galápagos, and Iceland overlying the most currently active. The Hawaii hotspot is perhaps the best known volcanic hotspot on Earth, responsible for the Hawaiian Islands in the Pacific Ocean. The Réunion hotspot is a Volcanic hotspot which currently lies under the Island of Réunion in the Indian Ocean. Galápagos hotspot is a volcanic hotspot responsible for the formation of the Galápagos Islands in the Pacific Ocean. The Iceland hotspot is a hotspot which is partly responsible for the high volcanic activity which has formed the island of Iceland.

Most hotspot volcanoes are basaltic because they erupt through oceanic lithosphere (e. Basalt (bəˈsɔːlt ˈbeisɔːlt ˈbæsɔːlt is a common Extrusive Volcanic rock. The lithosphere (IPA, from the Greek λίθος for "rocky" + σφαίρα for "sphere" is the solid outermost shell of a rocky Planet. g. , Hawaii, Tahiti). The Hawaiian Islands, once known as the Sandwich Islands, form an Archipelago of 19 Islands and Atolls numerous smaller Tahiti is the largest Island in the Windward group of French Polynesia, located in the Archipelago of Society Islands in the As a result, they are less explosive than subduction zone volcanoes, in which water is trapped under the overriding plate. In Geology, a subduction zone is an area on Earth where two tectonic plates meet and move towards one another with one sliding underneath the other Where hotspots occur under continental crust, basaltic magma is trapped in the less dense continental crust, which is heated and melts to form rhyolites. The continental crust is the layer of granitic, Sedimentary, and Metamorphic rocks which form the Continents and the areas of shallow seabed Basalt (bəˈsɔːlt ˈbeisɔːlt ˈbæsɔːlt is a common Extrusive Volcanic rock. Magma (Plurals magmas and magmata) is molten rock that sometimes forms beneath the surface of the Earth (or any other Terrestrial planet This page is about a volcanic rock For the ghost town see Rhyolite Nevada, and for the satellite system see Rhyolite/Aquacade. These rhyolites can be quite hot and form violent eruptions, despite their low water content. This page is about a volcanic rock For the ghost town see Rhyolite Nevada, and for the satellite system see Rhyolite/Aquacade. For example, the Yellowstone Caldera was formed by some of the most powerful volcanic explosions in geologic history. The Yellowstone Caldera is the volcanic Caldera in Yellowstone National Park in the United States. However, when rhyolitic magma is completely erupted, it may eventually turn into basaltic magma because it is no longer trapped in the less dense continental crust. An example of this activity is the Ilgachuz Range in British Columbia, which was created by an early complex series of trachyte and rhyolite eruptions, and late extrusion of a sequence of basaltic lava flows. The Ilgachuz Range is a name given to an extinct Shield volcano in British Columbia, Canada. Trachyte is an Igneous, Volcanic rock with an Aphanitic to Porphyritic texture This page is about a volcanic rock For the ghost town see Rhyolite Nevada, and for the satellite system see Rhyolite/Aquacade. [5]

Contents

Following the trail of a hotspot

As the continents and seafloor drift across the mantle plume, "hotspot" volcanoes generally leave unmistakable evidence of their passage through seafloor or continental crust. "Ocean Floor" redirects here For the 2001 song by Audio Adrenaline, see Lift (Audio Adrenaline album. A mantle plume is an upwelling of abnormally hot rock within the Earth's mantle. In the case of the Hawaiian hotspot, the islands themselves are the remnant evidence of the movement of the seafloor over the hotspot in the Earth's mantle. The Yellowstone hotspot emerged in the Columbia Plateau of the US Pacific Northwest. The Columbia River Plateau is a geologic and geographic region that lies across parts of the U The Pacific Northwest is a region in the northwest of North America (the term refers to the land not the ocean The Deccan Traps of India are the result of the emergence of the hotspot currently under Réunion Island, off the coast of eastern Africa. The Deccan Traps are a Large igneous province located on the Deccan Plateau of west-central India (between 17-24N 73-74E and one of the largest Volcanic Réunion ( French: Réunion or formally La Réunion; previously Île Bourbon) is an island located in the Indian Ocean, east of Geologists use hotspots to help track the movement of the Earth's plates. Such hotspots are so active that they often record step-by-step changes in the direction of the Earth's magnetic poles. Paleomagnetism is the study of the record of the Earth's magnetic field preserved in various Magnetic Minerals through time Thanks to lava flows from a series of eruptions in the Columbia Plateau, scientists now know that the reversal of magnetic poles takes about 5,000 years, fading until there is no detectable magnetism, then reforming in near-opposite directions. Lava is molten rock expelled by a Volcano during an eruption When first expelled from a volcanic vent it is a Liquid at Temperatures The Columbia River Plateau is a geologic and geographic region that lies across parts of the U A geomagnetic reversal is a change in the orientation of Earth's magnetic field such that the positions of magnetic north and magnetic south become interchanged In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials.

Hotspots versus island arcs

Hotspot volcanoes should not be confused with island arc volcanoes. A volcanic arc is a chain of volcanic islands or Mountains formed by Plate tectonics as an oceanic Tectonic plate subducts under While each will appear as a string of volcanic islands. Island arcs are formed by subducting, converging tectonic plates. In Geology, a subduction zone is an area on Earth where two tectonic plates meet and move towards one another with one sliding underneath the other When one oceanic plate meets another, the denser plate is forced downward into a deep ocean trench. This plate melts and becomes new molten material that fuels a chain of volcanoes, such as the Aleutian Islands near Alaska. The Aleutian Islands (possibly from Chukchi aliat, " Island " are a chain of more than 300 small volcanic islands forming a Volcanic Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent

List of hotspots

[6]

Distribution of selected hotspots. The numbers in the figure are related to the listed hotspots on the left.
Distribution of selected hotspots. The numbers in the figure are related to the listed hotspots on the left.
World map showing the locations of selected prominent hotspots. 1) Divergent plate boundaries, 2) Transform plate boundaries, 3) Convergent plate boundaries, 4) Plate boundary zones, 5) Selected prominent hotspots
World map showing the locations of selected prominent hotspots. 1) Divergent plate boundaries, 2) Transform plate boundaries, 3) Convergent plate boundaries, 4) Plate boundary zones, 5) Selected prominent hotspots
Over millions of years, the Pacific Plate has moved over the Hawaii hotspot, creating a trail of underwater mountains that stretch across the Pacific
Over millions of years, the Pacific Plate has moved over the Hawaii hotspot, creating a trail of underwater mountains that stretch across the Pacific
Over millions of years, the Pacific Plate has moved over the Bowie hotspot, creating the Kodiak-Bowie Seamount chain in the Gulf of Alaska
Over millions of years, the Pacific Plate has moved over the Bowie hotspot, creating the Kodiak-Bowie Seamount chain in the Gulf of Alaska

Former hotspots

References

  1. ^ "Hotspots": Mantle thermal plumes
  2. ^ Earth's interior: Raising hot spots
  3. ^ Christiansen, Robert L. The Tristan hotspot is a volcanic hotspot which is responsible for the volcanic activity which forms the volcanoes in the southern Atlantic Ocean. The Yellowstone Caldera is the volcanic Caldera in Yellowstone National Park in the United States. The Mackenzie hotspot was a hotspot that existed about 1267 million years ago across Canada from the Northwest Territories and Nunavut. ; Foulger, G.R. & Evans, John R. Gillian Foulger is a Professor of Geophysics at Durham University. (2002), “Upper-mantle origin of the Yellowstone hotspot”, Geological Society of America Bulletin (Geological Society of America) 114 (10): 1245-1256, <http://www.dur.ac.uk/g.r.foulger/Offprints/Yellowstone.pdf> 
  4. ^ Jonathan T. Hagstrum. Antipodal hotspots and bipolar catastrophes: Were oceanic large-body impacts the cause?. Retrieved on 2008-03-21. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 630 - Byzantine emperor Heraclius restores the True Cross to Jerusalem.
  5. ^ Report on Preliminary Geology and Geochemistry of the Ilga Claim group
  6. ^ Steinberger B. , (2000), Plumes in a convecting mantle: Models and observations for individual hotspots, Journal of Geophysical Research, volume 105 (B5), pages 11127-11152

External links

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