Volcanoes

Volcanoes, like earthquakes , occur in particular regions. The pattern of volcano distributions is another important clue to understanding plate tectonic processes. The spatial relationship between volcanoes and earthquakes, as well as the differing styles of volcanic eruption, are two other keys to interpreting plate interactions.

 

Volcanoes provide samples of the Earth's interior that we would otherwise never be able to access. They contribute gases to the atmosphere and water to the oceans. Volcanoes are also an integral part of Earth's plate tectonic cycle. New oceanic lithosphere is created by eruptions along the mid-ocean ridge system. Old lithosphere is destroyed in subduction zones, although some of it resurfaces through the arc volcanoes that overlie subducting slabs.

Most of the world's volcanic eruptions occur beneath the ocean, along the mid-ocean ridge system. These lavas chill under water to form blobby "pillows," which are characteristic of submarine eruptions. In Iceland the mid-ocean ridge actually rises above sea level. Here the basaltic lavas fountain and flow effusively, rather than explosively.

 

 

 

 

 

 

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