Tectonic–climatic interaction have sculpted their local and regional environments. Aside from admiring their majestic beauty, one might wonder how these geologic wonders work and what role they play in changing the landscape and atmosphere. Principally, volcanoes are geologic features that exude magmatic material from below Earth's surface onto the surface. Upon reaching the surface, the term "magma" disappears and "lava" becomes the common nomenclature. This lava cools and forms igneous rock. By examining igneous rocks, it is possible to derive a chain of events that led from the original melt of the magma to the crystallization of the lava at Earth's surface.
Magma chamber of magma chambers can be mapped using seismology: seismic waves from earthquakes move more slowly through liquid rock than solid, allowing measurements to pinpoint the regions of slow movement which identify magma chambers. As a volcano erupts, surrounding rock will collapse into the emptying chamber. If the chamber's size is reduced considerably, the resulting depression at the surface can form a caldera. Magma chamber A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is under great pressure, and, given enough time, that pressure can