Amazing Video of a Pyroclastic Flow at Santiaguito in Guatemala

Santa Maria (which is known also as Santiaguito) in Guatemala put on quite a show, with impressive explosive eruptions that produced numerous pyroclastic flows (also known as pyroclastic density currents, or PDCs) during May 2014. As many of you know, pyroclastic flows are some of the most deadly of the volcanic hazards. However, an intrepid geologist from the INSIVUMEH (the geological survey of Guatemala which monitors the country's copious volcanic activity), got close enough to capture some amazing footage of a pyroclastic flow in action. Pyroclastic flows are more or less avalanches made of hot volcanic debris. They can be formed from the collapse of an ash column when the force pushing the volcanic debris (tephra) can no longer push that material up against gravity, and it falls back down to earth as a flow. They can also be formed from the disintegration of a volcanic dome, where lava is ...