What You Should Know About Mt. Vesuvius, the World's Most Famous Volcano

Mt. Vesuvius is an Italian volcano that erupted on August 24* A.D. 79 blanketing the towns and 1000s of residents of Pompeii, Stabiae, and Herculaneum. Pompeii was buried 10' deep, while Herculaneum was buried under 75' of ash. This volcanic eruption is the first to be described in detail. The letter-writing Pliny the Younger was stationed about 18 mi. away in Misenum from which vantage point he could see the eruption and feel the preceding earthquakes.

His uncle, the naturalist Pliny the Elder, was in charge of area warships, but he turned his fleet to rescuing residents and died.

_{*In Pompeii Myth-Buster, Professor Andrew Wallace-Hadril argues that the event occurred in the fall.Translating Pliny's Letter adjusts the date to September 2, to coincide with later calendar changes. This article also explains the dating to A.D. 79, the first year of Titus' reign, a year not referred to in the relevant letter.}

Historical Importance:

In addition to Pliny's recording, the sights and sounds of the first volcano to be described in detail, the volcanic covering of Pompeii and Herculaneum provided an amazing opportunity for future historians: The ash preserved and protected a vibrant city against the elements until future archaeologists unearthed this snapshot in time.

• Letter about the death of his uncle and the appearance of the volcano, from Pliny the Younger to Tacitus the historian

Eruptions:

Mt. Vesuvius had erupted before and continued to erupt about once a century until about A.D. 1037, at which point the volcano grew quiet for about 600 years. During this time, the area grew, and when the volcano erupted in 1631, it killed about 4000 people. During the rebuilding efforts, the ancient ruins of Pompeii were discovered on March 23, 1748.

Today's population around Mt. Vesuvius is about 3 million, which is potentially catastrophic in the area of such a dangerous "Plinian" volcano.

Precursors and the Volcanic Eruption in A.D. 79:

Prior to the eruption, there were earthquakes, including a substantial one in A.D. 62* that Pompeii was still recovering from in 79. There was another earthquake in 64, while Nero was performing in Naples. Earthquakes were seen as facts of life. However, in 79, springs and wells dried up, and in August, the earth cracked, the sea became turbulent, and the animals showed signs that something was coming. When the eruption of the 24th of August began, it looked like a pine tree in the sky, according to Pliny, spewing noxious fumes, ash, smoke, mud, stones, and flames.

_{* In Pompeii Myth-Buster, Professor Andrew Wallace-Hadril argues that the event occurred in 63.}

Type of Volcano:

Named after the naturalist Pliny, the type of eruption of Mt. Vesuvius is referred to as "Plinian." In such an eruption a column of various materials (called tephra) is ejected into the atmosphere, creating what looks like a mushroom cloud (or, perhaps, pine tree). Mt. Vesuvius' column is projected to have reached about 66,000' in height.

Ash and pumice spread by the winds rained for about 18 hours. Buildings started to collapse and people began to escape. Then came high-temperature, high-velocity gasses and dust, and more seismic activity.

_References:

• _{Volcanic Phenomena at Pompeii}
• _{[formerly at < www.mnsu.edu/emuseum/archaeology/sites/europe/pompeii.html> Pompeii]}
• _{[formerly at <volcano.und.edu/vwdocs/volc_images/img_vesuvius.html> Vesuvius Italy]}
• _{[formerly at <vulcan.fis.uniroma3.it/vesuvio/79_eruption.html> The 79 AD Eruption of Vesuvius]}