How are pyroclastic flows created and why are they dangerous?
What will be an ideal response?
ANSWER: A volcano with a viscous magma content with a high concentration of volatiles will froth to form pumice and explode violently, fueled by the expansion of volatile gasses. The ash forms of shards of volcanic glass or shattered pumice. If the cloud is heavy enough, the ash and steam may roll down the slope of the volcano as a pyroclastic flow.
A pyroclastic flow has high steam temperatures, contains dense ash, and is violently turbulent, causing catastrophic danger inside the flow. The flow moves at very high speed and can travel up to 20 km from the volcano, making it very difficult to escape or avoid.
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What will be an ideal response?
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