University of Edinburgh

BSL Geography Glossary - Pyroclastic Density Current - definition

Definition: During an explosive volcanic eruption, gravity can cause the eruption column to collapse creating a pyroclastic density current. The material in the current will be very hot, about 800°C, and can travel with speeds of 50 to 100 miles per hour. Pyroclastic density currents contain volcanic stones and rocks. During an eruption in Pompeii, Italy, people and animals were killed and then buried by pyroclastic density currents, and only rediscovered recently.