Volcanic crater
A volcanic crater is an approximately circular depression in the ground caused by volcanic activity.[1] It is typically a bowl-shaped feature containing one or more vents. During volcanic eruptions, molten magma and volcanic gases rise from an underground magma chamber, through a conduit, until they reach the crater's vent, from where the gases escape into the atmosphere and the magma is erupted as lava. A volcanic crater can be of large dimensions, and sometimes of great depth. During certain types of explosive eruptions, a volcano's magma chamber may empty enough for an area above it to subside, forming a type of larger depression known as a caldera.
Geomorphology
In most volcanoes, the crater is situated at the top of a mountain formed from the erupted volcanic deposits such as
A crater may be breached during an eruption, either by explosions or by lava, or through later erosion. Breached craters have a much lower rim on one side.
Some volcanoes, such as maars, consist of a crater alone, with scarcely any mountain at all. These volcanic explosion craters are formed when magma rises through water-saturated rocks, which causes a phreatic eruption. Volcanic craters from phreatic eruptions often occur on plains away from other obvious volcanoes. Not all volcanoes form craters.
See also
- Caldera – Cauldron-like volcanic feature formed by the emptying of a magma chamber
References
- ^ "Glossary of Terms: C". physicalgeography.net. Retrieved 2008-04-12.
- ^ "Volcanic Craters". US National Park Service. Retrieved 30 June 2023.