Final answer:
A volcanic eruption is the crustal change that involves the release of large amounts of heat, explained by the theory of plate tectonics and the presence of hotspots beneath the Earth's crust.
Step-by-step explanation:
The crustal change that involves the release of large amounts of heat is a volcanic eruption. During a volcanic eruption, magma from the Earth's mantle makes its way to the surface, releasing not only molten rock but also a tremendous amount of heat into the environment. The heat can significantly affect local temperatures and cause pyroclastic flows, which incinerate nearly everything in their path.
Plate tectonics is the geological theory that explains various crustal changes, including volcanic eruptions. The Earth's crust is broken up into multiple tectonic plates that float on the semi-fluid asthenosphere beneath them. The boundaries where these plates interact are often sites of intense geological activity, such as earthquakes, mountain formation, and volcanic eruptions.
When it comes to hotspots, these are areas in the mantle where heat rises in plumes from deep within the Earth. As a tectonic plate moves over a hotspot, the heat can lead to the creation of a chain of volcanoes. For example, the Hawaiian island chain was formed by the Pacific Plate moving over such a hotspot. Not only do hotspots form volcanic islands, but they can also be found under continental crust, as with the Yellowstone hotspot, producing significant volcanic activity.