lava lake
Lava lakes can be as deep as 120 m (400 ft), and can take as long as 30 years to cool and solidify. Active lava lakes typically consist of a partially solidified shiny gray crust because its surface is constantly cooled by the atmosphere. The crust is seldom more than 5-30 cm thick, or more than a few minutes or hours old, because the crust continually circulates, breaks, and sinks into the moving molten lava below. The pattern of movement on the surface of lava lakes is often compared to the type of large-scale movement that occurs between the huge plates that make up the Earth's crust, including subduction, spreading, and strike-slip movement. Lava lakes occur at relatively few volcanoes in the world. For example, since 1980, lava lakes have formed at Kilauea Volcano in Hawai'i, Mount Erebus in Antarctica (involving rare phonolitic lava), Erta' Ale in Ethiopia and Nyiragongo in Zaire. Related category GEOLOGY AND PLANETARY SCIENCE Source: U.S. Geological Survey Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |