Pyroclastic flows are a leading cause of eruption-related deaths. Now, lab tests reveal the mind-bending reason they may rush down a volcano’s flanks.

Pyroclastic flows are made up of a mix of hot lava, pumice, ash and volcanic gases. They can reach temperatures of up to 1,000 degrees Celsius and can—in extreme cases—move down the slopes of ...

Pyroclastic flows contain a deadly combination of hot rock fragments and gas. Temperatures regularly top 1,000 degrees Fahrenheit, and these torrents can careen down mountainsides at hundreds of ...

Pyroclastic flow is how 30,000 people died in the eruption of Mount Pelee in 1902. When Vesuvius erupted in 79 A.D., more than 13,000 people died in pyroclastic flow, although the exact death toll ...

Image: R. Simmon / NASA. Terra/MODIS image of potential pyroclastic flow deposits in the ocean west of Paluweh in Indonesia, taken February 2, 2013. Image: R. Simmon / NASA.

Pyroclastic flows are a mixture of hot gas along with volcanic matter, like ash and rock fragments, she said. They are incredibly hot and can travel faster than a moving vehicle in some cases.

Even some of the fastest known pyroclastic flows observed, such as the blast at Mount St. Helens, was moving around ~600 kilometers per hour (370 mph). So, then what if the flow was dense instead?

These pyroclastic flows, or pyroclastic density currents, can travel at speeds of hundreds of metres per second and can travel tens to hundreds of miles from their source.

When Vesuvius erupted in 79 A.D., pyroclastic flows of more than 900 degrees instantly vaporized the flesh of the residents of the nearby town of Herculaneum, while the people of Pompeii perished ...

The most recent pyroclastic flows with significant reach were recorded on Feb. 10, 2022, Oct. 23, 2021, Dec. 13, 2020, and Feb. 11, 2014, Marco Viccaro, president of Italy’s national volcanology ...

The pyroclastic flow sped down a slope of broken rock, or talus scree, called Sciara del Fuoco. Though a few hundred residents call Stromboli home, the eruption did not affect any homes or buildings.

In Guatemala, pyroclastic flow from Sunday’s eruption topped 1,800 degrees Fahrenheit (about 1,000 degrees Celsius), CNN meteorologist Ivan Cabrera said.