Final answer:
An explosive eruption produces a pyroclastic flow by collapsing the eruptive column and sending an avalanche of hot gases, ash, and rock materials at high speeds capable of destroying nearly everything in their path and preserving the buried materials.
Step-by-step explanation:
An explosive eruption produces a pyroclastic flow by emitting a mixture of hot gases, ash, and rock materials from the volcano at high speeds. Pyroclastic flows occur when the eruptive column collapses, sending an avalanche of volcanic debris downslope. The resulting flows can move at incredible speeds, often over 60 mph, and reach temperatures of about 1,000 degrees Celsius. This voluminous, fast-moving, and hot material destroys nearly everything in its path through a combination of thermal incineration and mechanical force.
As seen during the eruption of Mount Vesuvius, pyroclastic flows can drastically alter the landscape, burying cities like Pompeii and Herculaneum under a dense layer of ash and rock, preserving the ruins and organic materials for centuries. The material ejected during the eruption creates a rough, hilly region surrounding the crater rim, which is also known as the ejecta blanket.