Hotspots are not usually located on the edges of tectonic plates, above mantle plumes, where the convection of the Earth’s mantle creates a column of hot material that rises until it reaches the crust, which tends to be thinner than in other areas of the Earth. The temperature of the plume causes the crust to melt and form pipes, which can vent magma. Because the tectonic plates move whereas the mantle plume remains in the same place, each volcano becomes dormant after a while and a new volcano is then formed as the plate shifts over the hotspot. The Hawaiian Islands are thought to be formed in such a manner, as well as the Snake River Plain, with the Yellowstone Caldera of the North American plate currently above the hot spot. Another example is India’s Deccan plateau which is the result of lava outflow from the Reunion hotspot. in
CHRONICLE IAS ACADEMY  Chronicle IAS Academy subsidence of a crater. (xi) Geysers: They are intermittent hot springs that from time to time spout steam and hot water from their craters. (xii)Fumaroles: It is a vent through which there is emission of gases and water vapour. (xiii)Cryptodomes: These are formed when viscous lava forces its way up and causes a bulge. The 1980 eruption of Mount St. Helens was an example. Lava under great
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