History - Ancient history - Volcanoes - Pompeii - Mount Vesuvius
You are in Pompeii in AD 79. After hours of falling ash, a dark cloud suddenly races from Mount Vesuvius toward the city. What is now the greatest danger?
Correct!
The dark cloud is a pyroclastic flow. This mixture of hot gases, ash and rock fragments travels down the volcano at tremendous speed. It can reach temperatures of several hundred degrees and moves far faster than a fleeing person.
Pompeii was not buried by a great lava flow, but mainly by ash and other volcanic material. Those layers preserved buildings, everyday objects and even the cavities left by many victims' bodies for almost 1,700 years.
Source: Archaeological Park of Pompeii
