What is a pyroclastic flow?

A pyroclastic flow is a fast-moving, highly destructive current of hot gas and volcanic matter that travels down the slopes of a volcano. These dense currents are produced by explosive eruptions and consist of mixed materials ranging from heavy rocks to lighter ashes. They are recognized as the deadliest of all volcanic hazards.

What we know

• A pyroclastic flow is a fast-moving current of hot gas and volcanic matter that flows along the ground away from a volcano. [1, 2]
• Pyroclastic flows are considered the deadliest of all volcanic hazards and are produced by certain explosive eruptions. [2]
• The denser components of pyroclastic currents are specifically referred to as pyroclastic flow, while lighter components are known as pyroclastic surges. [2]
• Pyroclastic currents can travel at extremely high speeds and possess extremely high temperatures. [2]

Where to go next

• what caused itHow do explosive volcanic eruptions occur?
• a case in pointWhat happens during a Plinian eruption?
• compared withWhat are pyroclastic surges?
• the bigger pictureHow are clastic rocks classified?
• how we knowWhat are lapilli and volcanic bombs?
• an unexpected connectionDo pyroclastic flows happen on other worlds?Pyroclastic currents are not unique to Earth and can also be observed on other astronomical bodies such as the moon.

Sources

• [1]pyroclastic flow (Wikidata Q221616) · CC0 1.0
• [2]Pyroclastic flow · CC BY-SA 4.0
• [3]Clastic rock · CC BY-SA 4.0
• [4]Lapilli · CC BY-SA 4.0
• [5]Mount Vesuvius · CC BY-SA 4.0