Volcanism in the Galapagos Islands
Lava Tube and Pit Crater
|An inside view of a lava tube and a pit crater, both pictures show a collapsed top. Picture source: http://www.rit.edu/~rhrsbi/GalapagosPages/Vulcanism6.html|
Lava tubes form when the top layer of a flow solidifies while underneath the lava still flows downhill quickly. The lava flow will eventually form a tube like structure that are usually five to six meters wide and up to ten meters in height. Once the lava runs dry a huge, hallow tube underground is all that is left. Lava tubes can be seen on Puerto Ayora and Bellavista, on Santa Cruz Island.