<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 volcano 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 eruption . </P> <P> Mount Vesuvius spewed forth a deadly cloud of tephra and gases to a height of 33 kilometres (21 mi), ejecting molten rock, pulverized pumice and hot ash at the 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>

When did the eruption of mount vesuvius occur