Related topics: geologists

Oral traditions and volcanic eruptions in Australia

In Australia, the onset of human occupation (about 65,000 years?) and dispersion across the continent are the subjects of intense debate and are critical to understanding global human migration routes. A lack of ceramic artifacts ...

A twist in the story of volcanic eruptions and mass extinctions

An emerging scientific consensus is that gases—in particular carbon gases–released by volcanic eruptions millions of years ago contributed to some of Earth's greatest mass extinctions. But new research at The City College ...

Mapping the path of climate change

Since 1880, the Earth's temperature has risen by 1.9 degrees Fahrenheit and is predicted to continue rising, according to the NASA Global Climate Change website. Scientists are actively seeking to understand this change and ...

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.

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