Volcanic Hazards | Pyroclastic Flow, Pyroclastic Surge & Tephra

Pyroclastic flows from Unzen were generated by gravitational collapse of the growing lava dome, near the city of Shimabara, Nagasaki (1991). Most of the flows traveled from 1 to 3 km, but some flows reached more than 4 km, burning houses and killing people in the evacuated zone of Kita-kamikoba on the eastern foot of the volcano.The velocities of the flows ranged from 15 to 25 m/s on the gentle middle flank. Scientific paper: http://link.springer.com/article/10.1007/BF00301514#page-1 Other detai

Pyroclastic flows may be even more destructive than previously thought | Science News

Surviving a Pyroclastic Flow

You must c C reate an account to continue watching

Pyroclastic flows (referred to more often today, as pyroclastic density currents) are rapidly moving avalanches of hot rock, dust and gas that flow down the sides of a volcano. What makes them especially devastating is that they are extremely hot and can travel for several miles from a volcano. They can form during an eruption when hot pulverized rock and gas that first rapidly rises into the sky falls back, forming pyroclastic flows that race down the sides of the volcano. Other times, pyroclas