GEOLOGY

Detailed explanation-1: -Mantle plumes are the likely cause of “hot spots, ” volcanic regions not created by plate tectonics. As a mantle plume reaches the upper mantle, it melts into a diapir. This molten material heats the asthenosphere and lithosphere, triggering volcanic eruptions.

Detailed explanation-2: -Mantle plumes can be emitted from the core-mantle boundary region to reach the Earth’s crust. Because of the lateral displacement of the tectonic plates at the surface, the mantle plumes can create a series of aligned hot-spot volcanoes. A mid-ocean ridge and a subducted plate are also shown.

Detailed explanation-3: -Hot spot volcanoes occur far from plate boundaries. Because the hot spot is caused by mantle plumes that exist below the tectonic plates, as the plates move, the hot spot does not, and may create a chain of volcanoes on the Earth’s surface.

Detailed explanation-4: -As the tectonic plate moves over the stationary hot spot, the volcanoes are rafted away and new ones form in their place. This results in chains of volcanoes, such as the Hawaiian Islands.

Detailed explanation-5: -Mantle plumes influence surface processes, including continental break-up and mass extinctions. The location of two large low-seismic-velocity provinces in the lowermost mantle can be associated with most present-day hotspots and ancient large igneous provinces.