Related topics: volcanic ash · earthquake · nasa · satellite · glaciers

Climbers to pay $13 fee on popular Mount Fuji trail

Hikers using the most popular route to climb Japan's Mount Fuji will be charged $13 each from July, with numbers capped to ease congestion and improve safety, a regional official said Tuesday.

Mars had its own version of plate tectonics

Plate tectonics is not something most people would associate with Mars. In fact, the planet's dead core is one of the primary reasons for its famous lack of a magnetic field. And since active planetary cores are one of the ...

NASA's Juno probe makes another close flyby of Io

The Juno spacecraft has revealed some fascinating things about Jupiter since it began exploring the system on July 4th, 2016. Not only is it the first robotic mission to study Jupiter up close while orbiting it since the ...

Ice and fire: Antarctic volcano may hold clues to life on Mars

On Deception Island in Antarctica, steam rises from the beaches, and glaciers dot the black slopes of what is actually an active volcano—a rare clash of ice and fire that provides clues to scientists about what life could ...

page 1 from 40

Volcano

A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot, molten rock, ash, and gases to escape from below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time. The word volcano is derived from the name of Vulcano island off Sicily. In turn, it was named after Vulcan, the Roman god of fire.

Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust (called "non-hotspot intraplate volcanism"), such as in the African Rift Valley, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America and the European Rhine Graben with its Eifel volcanoes.

Volcanoes can be caused by mantle plumes. These so-called hotspots, for example at Hawaii, can occur far from plate boundaries. Hotspot volcanoes are also found elsewhere in the solar system, especially on rocky planets and moons.

This text uses material from Wikipedia, licensed under CC BY-SA