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A hotspot's position on the Earth's surface is independent of tectonic plate boundaries, and so hotspots may create a chain of volcanoes as the plates move above them. There are two hypotheses that attempt to explain their origins. One suggests that hotspots are due to mantle plumes that rise as thermal diapirs from the core–mantle boundary. [2]
To qualify as a biodiversity hotspot on Myers' 2000 edition of the hotspot map, a region must meet two strict criteria: it must contain at least 1,500 species of vascular plants (more than 0.5% of the world's total) as endemics, and it has to have lost at least 70% of its primary vegetation. [6] Globally, 36 zones qualify under this definition. [7]
The narrow vertical conduit, postulated to connect the plume head to the core-mantle boundary, is viewed as providing a continuous supply of magma to a hotspot. As the overlying tectonic plate moves over this hotspot, the eruption of magma from the fixed plume onto the surface is expected to form a chain of volcanoes that parallels plate motion ...
A volcanic arc is part of an arc-trench complex, which is the part of a subduction zone that is visible at the Earth's surface. A subduction zone is where a tectonic plate composed of relatively thin, dense oceanic lithosphere sinks into the Earth's mantle beneath a less dense overriding plate.
The Conservation International reassessed Myers definition of a hotspot and by 1999 criteria for a hotspot developed to be used globally. A hotspot needs 1,500 endemic vascular plant species and a loss of at least 30 percent of its original land. [2] [3] [4] With these criteria, 25 hotspots were identified in 1999 and published in the journal ...
Where hotspots are developed beneath the continents the products are different, as the mantle-derived magmas cause melting of the continental crust, forming granitic magmas that reach the surface as rhyolites. The Yellowstone hotspot is an example of continental hotspot magmatism, which also displays time-progressive shifts in magmatic activity.
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Hotspot (geology), an area of unusually high volcanic activity; Hot spot (veterinary medicine), an irritated skin lesion; Hot spot, a location with a high level of radioactive contamination; Biodiversity hotspot, a region of significant variety and variability of life; Hot spot effect in subatomic physics, regions of high energy density or ...