Pressures within pyroclastic flows may be as much as three times as great as observations had suggested.

Volcanologist Professor Chris Jackson discovers evidence of the deadly pyroclastic flow.

A lava flow was spotted by satellites winding down the flanks of Mount Etna during an explosive outburst on June 2, which also released a large pyroclastic flow in the opposite direction. | Credit ...

In the Philippines, Mayon is erupting spectacularly, creating a lava flow that stretches over 3 kilometers (2 miles) from the crater, 600-meter lava fountains, pyroclastic flows that followed gullies ...

Mount Etna, the rambunctious volcano on the Italian island of Sicily, grumbled back to life on Monday, spewing hot ash and lava in a pyroclastic flow, the nation's volcano monitoring body said.

But the defining event of Monday’s eruption was the more rare pyroclastic flow from the southwestern crater not visible from a distance.

Italy’s Mount Etna volcano violently erupted on Monday, sending plumes of toxic ash and smoke billowing into the sky as people on the mountain ran for safety to escape the danger.

But the defining event of Monday’s eruption was the more rare pyroclastic flow from the southwestern crater not visible from a distance.