Structure
Dark profile of Hualālai, showing typical shape of a shield volcano.
Because of their gradual buildup and near continuous eruptive characteristics, shield volcanoes are the largest volcanoes on Earth,[4][n 1] usually being at least 3 to 4 mi (5 to 6 km) across and surpassing 1,500 to 2,000 ft (457 to 610 m) in height. The largest shield volcano (and the largest active volcano) in the world is Mauna Loa in Hawaiʻi, which projects 13,677 ft (4,169 m) above sea level.[3]
Shield volcanoes are composed almost exclusively of basalt.[4] Their lower slopes are generally gentle (~2 degrees), but steepen with elevation (reaching ~10 degrees) before flattening near the summit, giving the volcanoes a convex shape.[1]
Over the volcano's lifespan, collapse-driven calderas that form on shield volcanoes are often filled up, and new ones formed elsewhere, in an ongoing cycle of collapse and regeneration.[4]
Dark profile of Hualālai, showing typical shape of a shield volcano.
Because of their gradual buildup and near continuous eruptive characteristics, shield volcanoes are the largest volcanoes on Earth,[4][n 1] usually being at least 3 to 4 mi (5 to 6 km) across and surpassing 1,500 to 2,000 ft (457 to 610 m) in height. The largest shield volcano (and the largest active volcano) in the world is Mauna Loa in Hawaiʻi, which projects 13,677 ft (4,169 m) above sea level.[3]
Shield volcanoes are composed almost exclusively of basalt.[4] Their lower slopes are generally gentle (~2 degrees), but steepen with elevation (reaching ~10 degrees) before flattening near the summit, giving the volcanoes a convex shape.[1]
Over the volcano's lifespan, collapse-driven calderas that form on shield volcanoes are often filled up, and new ones formed elsewhere, in an ongoing cycle of collapse and regeneration.[4]
No comments:
Post a Comment