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Where do stratovolcanoes erupt?
Stratovolcanoes are common at subduction zones, forming chains and clusters along plate tectonic boundaries where oceanic crust is drawn under continental crust (continental arc volcanism, e.g. Cascade Range, Andes, Campania) or another oceanic plate (island arc volcanism, e.g. Japan, Philippines, Aleutian Islands).
Why do stratovolcanoes erupt violently?
Stratovolcanoes can erupt with great violence. Pressure builds in the magma chamber as gases, under immense heat and pressure, are dissolved in the liquid rock. Because they form in a system of underground conduits, stratovolcanoes may blow out the sides of the cone as well as the summit crater.
What causes Stratovolcanoes to form?
An eruption of highly viscous (very sticky) magma tends to produce steep-sided volcanoes with slopes that are about 30–35°. That’s because the viscous volcanic material doesn’t flow that far from where it is erupted, so it builds up in layers forming a cone-shaped volcano known as a stratovolcano.
What are 3 characteristics of Stratovolcanoes?
A stratovolcano is a tall, conical volcano composed of one layer 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 highly viscous, and cools and hardens before spreading very far.
What causes stratovolcanoes to form?
Are stratovolcanoes explosive or effusive?
Explosive and Quiet Eruptions Stratovolcanoes typically alternate between explosive and non-explosive, or “effusive,” eruptions. Those relatively quiet effusive eruptions produce the lava flows, which are more fluid: in other words, less “viscous.” (Viscosity is a liquid’s resistance to flow.)
Why are stratovolcanoes worse than shield volcanoes?
Why do stratovolcanoes erupt violently and shield volcanoes do not? The difference is the viscosity of the lava. High-viscosity lavas do not flow easily. Pressure builds up within the magma chamber and eruptions are explosive and violent.
What are stratovolcanoes made up of?
What are Stratovolcanoes? Stratovolcanoes, also called composite volcanoes, are typically steep-sided, symmetrical cones built of alternating layers of lava flows, volcanic ash, and other eruptive products (see animation courtesy of Exploring the Environment).
What are the hazards of Stratovolcanoes?
Additionally, strato volcanoes are steep piles of ash, lava, and domes that are often rained heavily on, shaken by earthquakes, or oversteepened by intruding blobs of magma (or all of these). This makes the likelihood of landslides, avalanches, and mudflows all very high.
Why are eruptions of stratovolcanoes generally more explosive than those of shield volcanoes?
Stratovolcanoes show inter-layering of lava flows and pyroclastic material, which is why they are sometimes called composite volcanoes. Due to the higher viscosity of magmas erupted from these volcanoes, they are usually more explosive than shield volcanoes.