History Focus for August 24

A short focus on a person or event associated with this day in History.

Vesuvius - Elevation: 4,200 feet

Vesuvius is famous for the catastrophic eruption in 79 A.D. that buried the towns of Herculaneum and Pompeii. Stabiae and a number of other smaller settlements were also destroyed. Scientists believe that Vesuvius had two eruptions that rate among the largest known in Europe prior to the disaster of 79 A. D.. There was also a smaller eruption in 62 A. D.

The 79 A.D. eruption of Vesuvius was the first volcanic eruption ever to be described in detail. From 18 miles west of the volcano, Pliny the Younger, witnessed the eruption and later recorded his observations in two letters. He described the earthquakes before the eruption, the eruption column, air fall, the effects of the eruption on people, pyroclastic flows, and even tsunami. Because of his records volcanologists now use the term "plinian" to refer to sustained explosive eruptions which generate high-altitude eruption columns and blanket large areas with ash. It is estimated by his records that at times during the eruption the column of ash was 20 miles tall. About 1 cubic mile of ash was erupted in about 19 hours.

About 10 feet of tephra fell on Pompeii, burying everything except the roofs of some buildings. The city was abandoned and its location forgotten. Herculaneum was a more leisurely town about a third of the size of Pompeii and about a quarter of the population. Herculaneum did not have a major harbor nor was it a trade center. It was a seaside resort. Pyroclastic surges are responsible for the deaths in the city. Herculaneum was buried under 75 feet of ash deposited by a pyroclastic flow. About 5,000 people lived in the city at the time of the eruption.

In 1595, excavations discovered artifacts at Pompeii and centuries of pillaging followed. Archeological excavations began in the mid-nineteenth century. Now, much of Pompeii has been excavated and it has revealed much about how people lived during that time. We have also learned much about how they died during the eruption. There are numerous molds of people in their final moments. The molds generally show the people in various stages of agony. Deposits at Pompeii are dominated by air fall deposits of pumice and lapilli. Deposits at Herculaneum are dominated by pyroclastic flow deposits. Air fall deposits tend to be soft and can be scraped away with a shovel. Pyroclastic flow deposits tend to be hard because the hot ash tends to fuse together. Perhaps Pompeii is better known because the air fall deposits were easier to remove. Perhaps it was of greater interest since it was a larger, more important city.

The patron saint of. the city of Naples is San Gennaro. His special function is to preserve the Neopolitans from the fate met by the citizens of Pompeii and Herculaneum in 79 AD. Vesuvius stands 10 miles inland from the city. Despite the menacing presence of Vesuvius the area has been heavily populated for over 2,000. Clouds of steam, dust and ash swathe its crest. In 1631 a particularly severe eruption killed above 18,000 people. It is this event which the people of Naples commemorate through their patron saint. However, eruptions in this century have also been as spectacular if not as destructive. In 1906, after a week of sinister silence, Vesuvius exploded, sending red hot rocks and ash a mile high. Explosions burst its sides and lava flowed out, covering villages and killing people. From sea the mountain appears red like a huge glowing pyramid at night. The volcano has again become active in the past two years, possibly preparing for another blowout. But the people of Naples remain unshaken in their belief that San Gennaro will preserve them.

Sources: Compton’s Encyclopedia | Microsoft(R) Encarta(R) 96

© Phillip Bower