Mount Vesuvius

Mount Vesuvius Eruption of 79AD

WHAT IS IT? Mount Vesuvius is located just off the Gulf of Naples in Italy. It was created by the collision of the African and Eurasian plates. It is a stratovolcano, which is a volcano that is made up of many layers of hardened lava and ash. These layers are known as strata.

Leading up to the eruption in 79AD there were significant earthquakes in 62AD and 64AD, with many more in the four days before the eruption. The eruption released 4km3 of ash and rock composed of leucite and phonolite, covering the cities of Pompeii and Herculaneum completely.

PLINY THE YOUNGER The following is a quote from Pliny the Younger, an eyewitness to the eruption: “I cannot give you a more exact description of its appearance than by comparing to a pine tree; for it shot up to a great height in the form of a tall trunk, which spread out at the top as though into branches.”

“PLINIAN” From Pliny the Younger’s description of this eruption came the term “plinian.” This refers to a particular type of eruption characterized by a large column of gas and ash being shot high into the stratosphere. Plinian eruptions are also sometimes called “Vesuvius eruptions.”

STAGE ONE The event took place in two stages, the eruption and the flow. The eruption which is now called a plinian eruption probably lasted up to twenty hours. Pumice, a glassy sort of lava, rained down, leaving deposits of up to 2.8 meters.

STAGE TWO

Deadly rock and hot gas combined to create the second stage in the form of a pyroclastic flow. Pyroclastic flows can travel as fast as 700km an hour and reach temperatures of 1000°C.

REDISCOVERY Although quite forgotten, Pompeii and Herculaneum were very well preserved because of their ash covering. It wasn’t until the eighteenth century that Pompeii was rediscovered, and then only by accident.

HUMAN REMAINS Old buildings weren’t the only thing found in Pompeii. A shocking 1,150 human remains were also there. The falling ash, as it hardened, formed a sort of cast, which preserved the shape of bodies. Often quite detailed, it is easy to see exactly what these people had been doing when they died.

CASUALTIES Although 1,150 casts were found in Pompeii, it certainly did not represent all those who died due to the eruption. It is believed that about thirty-eight percent of those were killed by large rocks or collapsed roofs, and the other sixty-two percent likely died from inhaling ash or from falling debris.

BIBLIOGRAPHY Mount Vesuvius 79AD. (n.d.). Wikimedia Commons. Retrieved November 21, 2009, from File:Mt Vesuvius 79 AD eruption 3.svg: http://commons.wikimedia.org/wiki/File:Mt_Vesuvius_79_AD_eruption_3.svg Mount Vesuvius 79AD. (n.d.). Wikipedia. Retrieved November 15, 2009, from Mount Vesuvius: http://en.wikipedia.org/wiki/Mount_Vesuvius Naples – Italy: 16th Port of Call – SUNSHINE ROUTE (n.d). Retrieved November 22, 2009 from: http://www.solarnavigator.net/geography/naples_italy.htm Plinian Eruption. (n.d.). Wikimedia Commons. Retrieved November 21, 2009, from File: Plinian Eruption-blank.svg: http://commons.wikimedia.org/wiki/File:Plinian_Eruption-blank.svg Plinian Eruption. (n.d.). Wikipedia. Retrieved November 21, 2009, from Plinian Eruption: http://en.wikipedia.org/wiki/Plinian_eruption Stratovolcano. (n.d.). Wikipedia. Retrieved November 20, 2009, from Stratovolcano: http://en.wikipedia.org/wiki/Stratovolcano