How deadly, fast-moving flows of volcanic rock and gas cheat friction

Lab experiments show the mixtures travel so far and so fast by riding on air

Pyroclastic flow in an eruption

FAST FLOW  Simulating avalanches of volcanic material called pyroclastic flows in the lab show how these currents cover so much ground. 

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Dumping literal tons of hot volcanic material down a lab flume may finally have revealed how searing mixtures of hot gas and rock travel so far from volcanic eruptions.