<Tr> <Th> VEI </Th> <Td> 5 </Td> </Tr> <Tr> <Th> Impact </Th> <Td> Buried the Roman settlements of Pompeii, Herculaneum, Oplontis and Stabiae . </Td> </Tr> <P> Mount Vesuvius, a stratovolcano in modern - day Italy, erupted in 79 AD in one of the most catastrophic volcanic eruptions in European history . Historians have learned about the eruption from the eyewitness account of Pliny the Younger, a Roman administrator and poet . The event is the namesake for the Vesuvian type of volcanic eruptions . </P> <P> Mount Vesuvius violently spewed forth a deadly cloud of super-heated tephra and gases to a height of 33 km (21 mi), ejecting molten rock, pulverized pumice and hot ash at a massive rate of 1.5 million tons per second, ultimately releasing 100,000 times the thermal energy of the Hiroshima - Nagasaki bombings . Several Roman settlements were obliterated and buried underneath massive pyroclastic surges and ashfall deposits, the best known being Pompeii and Herculaneum . </P>

What happened to mount vesuvius in 79 ad