Mount Vesuvius is one of a line of volcanos where two tectonic plates (African and Eurasian) collide. The others volcanos along the plate are either extinct or haven’t erupted variously in tens of thousands or hundreds of years. Vesuvius in the only volcano to have erupted on mainland Europe for several centuries.
Mount Vesuvius has erupted often. Though there have been several large eruptions, the famous eruption of 79 AD was the most destructive. Vesuvius has erupted every century or so and more but has not erupted since 1944. Some eruptions have been so large that they blanketed all of southern Europe.
The 79 AD eruption that destroyed Pompeii and Herculaneum was described by Pliny (a Roman lawyer, author, and civil magistrate) in two letters to the historian Tacitus which have survived for almost two thousand years. Because of his thorough descriptions, the explosive eruption at Vesuvius is termed a “Plinian eruption.” According to Pliny, Vesuvius ejected a cloud of stones, ash and fumes about twenty miles high. The molten rock and pumice released was a hundred thousand times the thermal energy of the atomic bomb at Hiroshima.
An estimated 16,000 people died due to pyroclastic flows which are fast-moving currents of hot gas and rock (1800+° F) which can flow downhill at speed up to 450 mph. Today, Because of its location and explosive eruptions, Vesuvius is considered one of the most dangerous volcanoes in the world. The area is the most densely populated volcanic region in the world with 3,000,000 people living in nearby Naples and the surrounding areas.
Tomorrow, One of Pliny’s Letters on the eruption of Vesuvius.
Archaeological investigations constantly add to the body of knowledge about the dark days of Pompeii and Herculaneum. Two decades ago the story of the eruption of Vesuvius went that in August of 79 AD a quiet mountainside with vineyards growing on its slopes exploded killing an estimated 16,000 victims and burying two towns, several smaller communities, and much of the countryside under layers of ash and mud. Over time the names of the towns, even their existence, was lost to memory until they were rediscovered in the seventeenth and eighteenth centuries.
What is known for sure is that in February, 62 AD the area was rocked by an earthquake that caused massive destruction along the bay of Naples and in Pompeii. The city was undergoing restoration when the volcano erupted. Since six hundred sheep were reported to have died on the slopes of Vesuvius, the earthquake was likely associated with Vesuvius.
The main (actually only) eyewitness reports that survive of the eruption of Vesuvius and the destruction that followed are two letters from Pliny the Younger, a nephew of a prominent Admiral of the Roman fleet who died attempting to rescue survivors, written 25 years after the event. (They’ll have their own day later.) The actual date of the eruption has even been called into question. While August has long been the date attributed to the eruption, some experts claim that the cooler weather clothing the victims wore and the food in season – even some references in one of Pliny’s letters – indicate November 23rd as the correct date.
The residents of Pompeii, a busy trading town in Campania which was several centuries old, were originally believed to have been killed by suffocation from poisonous gases, experts now believe – based on the condition of the bodies (see pic of contorted limbs of cast of family unit at display in British Museum)– that they died from the superheated temperatures. The town was buried under 13-20 feet of pumice and ash. More wealthy resort town of Herculaneum was initially inundated by a flow of superheated ash (pyroclastic flow) that buried the town under about 75 feet of pumice and ash that hardened into “tuff” and encased the town in an airtight shell that left the town remarkably preserved. It has revealed fewer of its secrets because it lies beneath to small towns. (See pics)
Tomorrow, A Visit from Author V.C. Locey