Lava tube

[3][4] Lava tubes are often considered when preparing hazard maps or managing an eruptive crisis.

While the core of the channel tend to stay very hot, its sides cool down rapidly forming solidified walls called levees.

The surface of the flow solidify forming a crust which will thicken and lead to the formation of a lava tube.

A runner is a bead of lava that is extruded from a small opening and then runs down a wall.

Lava tubes can also be extremely long; one tube from the Mauna Loa 1859 flow enters the ocean about 50 kilometers (30 mi) from its eruption point, and the Cueva del Viento–Sobrado system on Teide, Tenerife island, is over 18 kilometers (11 mi) long, due to extensive braided maze areas at the upper zones of the system.

The largest of these lava tubes is 2 meters (7 ft) in diameter and has columnar jointing due to the large cooling surface.

Lunar lava tubes have been discovered[11] and have been studied as possible human habitats, providing natural shielding from radiation.

[18] Evidence of Martian lava tubes has also been observed on the Southeast Tharsis region and Alba Mons.

[19][20] Caves, including lava tubes, are considered candidate biotopes of interest for extraterrestrial life.

Valentine Cave, a lava tube in Lava Beds National Monument , California shows the classic tube shape; the grooves on the wall mark former flow levels.
Thurston Lava Tube in Hawaii Volcanoes National Park , Hawaii. The step mark, more visible on the right wall, indicates the depth at which the lava flowed for a period of time.
Rare characteristics of lava tubes are lava pillars . This is the Manjanggul lava pillar located in the Manjanggul lava tubes, on the island of Jeju-do , Korea .
Lavacicles on the ceiling of Mushpot Cave in Lava Beds National Monument
Close-up of a skylight on a coastal plain, with lava stalactites forming on the roof of the tube, Hawaii Volcanoes National Park
Entrance of a lava tube, Big island, Hawaii