underground cavities
Introduction
A cave, cavern or grotto is a more or less extensive cavity in the terrain formed by natural or artificial causes.[1] It is usually the result of some type of erosion by water currents, ice or lava, or less commonly, a combination of several of these factors. In the most common cases, caves are formed by the dissolution of limestone rock by slightly acidic water.
Sometimes it is suitable to serve as shelter for animals and humans, and can be adapted for housing in the form of cave houses and other anthropic uses. They are generally humid and dark; Some only fit one person, while others, such as the network in Mammoth Cave National Park (Kentucky), are kilometers long. There are very deep caverns such as in Abkhazia, where the greatest drop is reached in the Verióvkina cave with more than 2000 m below the surface level.
Training and classification
Contenido
Las cuevas se forman mediante procesos de espeleogénesis") que involucran actividad química, geológica, fuerzas tectónicas e influencias atmosféricas.
Dependiendo del momento en que se crearon las cuevas en relación con la formación de la roca que las componen, se pueden dividir en:.
Primary or volcanic caves
Some caverns form at the same time as the surrounding rock. These are called primary caves or syngenetic caves, according to the classification of J. Montoriol-Pous.[2].
A volcanic tube is formed during eruptive activity at the same time as the host rock (sygenetic character) by movements of fluid lava between already consolidated lava (rheogenetic character) and are the most common of these primary caves. The lava expelled by a volcano flows downwards and when the surface cools it hardens, acting as a thermal insulator under which the lava continues to flow until the eruption ends and ends up leaving an empty hole inside the tube.
The most important lava tube is located in Hawaii. Kazumura Cave, located near the coastal city of Hilo (Hawaii), is the longest and deepest tube in the world and is the eighth longest cave in the United States.