A volcano is actually a spot in Earth’s crust the place the floor is related to chambers of liquid rock under. Earth’s crust consists of tectonic plates that sit on high of hotter, softer rock within the mantle. Volcanoes most frequently happen on the boundaries the place plates meet. This occurs on land however there are additionally many underwater volcanoes, a few of that are very giant. There are additionally volcanoes, together with these in Hawaii, that sit in the course of tectonic plates. It’s thought that these are related to the mantle by 3000 km deep chimneys of liquid rock referred to as mantle plumes.
Based on the US Geological Society, there are about 1500 doubtlessly lively volcanoes on land. There are at all times dozens of them erupting. In 2020, greater than 60 volcanoes have erupted or continued to erupt.
Volcano are maybe finest recognized due to the hazards they current. Streams of lava can dissipate and destroy something of their path. Whereas explosions can inject large portions of ash into the ambiance. It’s thought that vast bouts of volcanic eruptions within the historic previous clogged up the ambiance, altering the local weather in drastic ways in which precipitated main extinction occasions.
There are additionally volcanoes on different worlds within the photo voltaic system. Olympus Mons on Mars is an extinct volcano. In the meantime, Io, a moon of Jupiter, is the photo voltaic system’s most geologically lively world with greater than 400 lively volcanoes surrounded by swimming pools of effervescent rock. Now we have additionally discovered loads of proof of ice volcanoes, together with on Pluto, which erupt not rock however compounds that might sometimes be liquids or gases on earth, similar to water and ammonia.