Stratovolcano

From Free net encyclopedia

(Redirected from Composite volcano)

A stratovolcano is a tall, conical mountain (volcano) composed of both hardened lava and volcanic ash. The shape of these volcanos is characteristically steep in profile because the lava flows that formed these volcanos were highly viscous, and so cooled and hardened before spreading very far. Such lava are classed as acidic to be high in silica. At the other end of the spectrum are shield volcanoes (such as Mauna Loa in Hawaii), which are formed from less viscous, basic lavas (high in metals such as magnesium and iron), giving them a wide base and more gently sloping profile. Many stratovolcanos exceed a height of 2500 m. They are often created by subduction of tectonic plates.

Although stratovolcanoes are sometimes called composite volcanoes, volcanologists prefer to use the term stratovolcano to distinguish among volcanoes because all volcanoes of any size have a composite (layered) structure — that is, are built up from sequential outpourings of eruptive materials.

Examples

Image:Sthelens1.jpg

Image:Kazbegi1.jpg

External link

de:Schichtvulkan et:Kihtvulkaan fr:Stratovolcan is:Eldkeila nl:Stratovulkaan no:Stratovulkan sk:Stratovulkán sv:Stratovulkan