Authorities emphasized there was no danger to the population, and the pyroclastic flow — a fast-moving mixture of rock fragments, gas and ash — was limited to about 2 kilometers (more than a ...

Pyroclastic density current (PDC): A turbulent, high-density flow composed of volcanic ash, lapilli and gases that descends rapidly along a volcano’s slope following an eruption.

The government agency wrote in a translated post that a pyroclastic flow, a combination of ash, rock, and gas, "probably produced by the collapse of material from the northern side of the Southeast ...

A volcanic eruption in Italy left people scurrying for cover from what officials are saying is a pyroclastic flow. Several videos circulating online show people running as smoke from the side of ...