What is a strato volcano?

Question

I need to know the definition of a strato volcano

Answer 1

A stratovolcano, also called a composite volcano, is a tall, conical volcano composed of many layers of hardened lava, tephra, and volcanic ash. These volcanoes are characterized by a steep profile and periodic, explosive eruptions. The lava that flows from them is viscous, and cools and hardens before spreading very far. The source magma of this rock is classified as acidic, having high to intermediate levels of silica (as in rhyolite, dacite, or andesite). This is in contrast to less viscous basic magma that forms shield volcanoes (such as Mauna Loa in Hawaii), which have a wide base and more gently sloping profile.

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 — they are built up from sequential outpourings of eruptive materials.


Stratovolcanoes are a common feature of subduction zones, forming chains or 'arcs' along tectonic plate boundaries where oceanic crust is subsumed under continental crust (Continental Arc Volcanism, e.g. Cascade Range, central Andes) or another oceanic plate (Island arc Volcanism, e.g. Japan, Aleutian Islands). The magma that forms stratovolcanoes arises when water, which is trapped both in hydrated minerals and in the porous basalt rock of the upper oceanic crust, is released into mantle rock of the asthenosphere above the sinking oceanic slab. The release of water from hydrated minerals is termed "dewatering," and occurs at specific pressure/temperature conditions for specific minerals as the plate subducts to lower depths. The water freed from the subducting slab lowers the melting point of the overlying mantle rock, which then undergoes partial melting and rises due to its density relative to the surrounding mantle rock, and pools temporarily at the base of the lithosphere. The magma then rises through the crust, incorporating silica rich crustal rock, leading to a final intermediate composition. When the magma nears the surface it pools in a magma chamber under the volcano. The relatively low pressure of the magma allows water and other volatiles (CO2, S2-, Cl-) dissolved in the magma to begin to come out of solution, much like when a bottle of carbonated water is opened. Once a critical volume of magma and gas accumulates, the obstacle provided by the volcanic cone is overcome, leading to a sudden explosive eruption.

Answer 2

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RE:
What is a strato volcano?
I need to know the definition of a strato volcano

Answer 3

Mt. St. Helens is a strato volcano. They're characterized by violent eruptions and pyroclastic flows. Lava from these volcano's have a very high gas content.

Answer 4

Boooooo... I've seen this question before.

Strato Volcanoes comprise the largest percentage (~60%) of the Earth's individual volcanoes and most are characterized by eruptions of andesite and dacite - lavas that are cooler and more viscous than basalt.

Answer 5

Stratovolcano
Steep, conical volcanoes built by the eruption of viscous lava flows, tephra, and pyroclastic flows, are called stratovolcanoes. Usually constructed over a period of tens to hundreds of thousands of years, stratovolcanoes may erupt a variety of magma types, including basalt, andesite, dacite, and rhyolite.

Answer 6

They used to be called shield volcanoes. Instead of a roundish cone, the volcano creates a long wall with its liquidy, non-violent eruptions.

Answer 7

Here's some links to give you alot of info on Volcanoes. :D

Answer 8

its a volcano that spews liquid hot magma into the stratosphere

Answer 9

Maybe it's one that has its head in the clouds! Har har.