Hotspots are anomalous areas of surface volcanism that cannot be directly
associated with plate tectonic processes. Many hotspots lie well within the
interiors of plates; an example is the volcanism of the Hawaiian Islands.
Other hotspots lie at or near an ocean ridge, an example
is the volcanism that forms Iceland. Much more voluminous than normal
ocean ridge volcanism; this volcanism resulted in a thick oceanic crust and
the elevation of Iceland above sea level.
In many cases hotspots lie at the end of well-defined lines of volcanic
edifices or volcanic ridges. These are known as hotspot tracks. The hotspot
track associated with the Hawaiian hotspot is the Hawaiian–Emperor island–
seamount chain that extends across the Pacific plate to the Aleutian Islands.
There is little agreement on the total number of hotspots
The definition of a hotspot tends to be quite subjective, partic-
ularly with regard to volcanism on or adjacent to plate boundaries. Hotspots
occur both in the oceans and on the continents. They do not appear to be
uniformly distributed over the Earth’s surface.