Monday, April 23, 2012

A Rain of Pumice and Ash

In the summer of AD 79, the Roman Empire was at its height. A Roman fleet was stationed at a town called Misentum, on the western coast of Italy about 150 miles south of Rome. Misentum was on the western horn of the Bay of Naples, and in one of its lavish seaside villas, the commander of the naval detachment, a philosopher named Pliny, laid on a blanket in the yard, writing his latest work. Pliny was famous, fat, rich, and Roman, and was attended to by a sizeable staff who answered every command he instituted.

Pliny's sister Plinia, who shared the villa with him, appeared and drew his attention to an oddly shaped cloud coming from inland. Pliny called for his shoes and moved to a place where he could better see what was happening. From the earth sprouted a vertical column of gray and white, rising straight up toward the sky. Once it reached a certain height, the cloud spread out to the side, so it gave the impression of a pine tree's umbrella canopy. Pliny, being a prolific writer of nature, immediately recognized it as curious enough to warrant a closer inspection. He most likely recognized it as a volcanic eruption, although he could not tell at first from which specific hill it was rising. Later, it would be revealed to be Vesuvius, and what Pliny was observing was only the first stage of its colossal eruption.

Pliny decided to ready a ship to allow him a view from the sea. He offered to bring Plinia's 17-year-old son with him, but the boy, unimpressed by the phenomenon, preferred to remain in the villa, and his mother refused to leave her child. As Pliny therefore headed toward a small, fast cutter he had chosen to take, he received an urgent letter from Rectina, the wife of one of his friends, pleading for assistance; their house was in a town at the foot of the erupting volcano, and they had no means of escape except by sea. Grasping the scope of the danger, Pliny changed his orders and commanded several larger galleys to accompany him into the the heart of the Bay of Naples to evacuate as many as possible from the coastal villages of Pompeii and Stabia. On his way in, Pliny noted that the cloud he had first seen owed its gray and white coloring to the fact that it was comprised of rocks, ash, and pumice projected violently into the air; now, with some time having passed, that cloud of debris was raining down on the Bay, the ships, and the coastal towns, pelting the inhabitants and making passage difficult, even by sea.

Pliny, all the while painstakingly noting the natural effects in his journal, commanded his ships into the heart of the bay, even as numerous other Pompeiian and Stabian ships were frantically fleeing the volcano. His helmsman, concerned about the danger, advised Pliny to flee, to which the commander replied, "Fortes fortuna iuvat" - "Fortune favors the brave" - and they made for the town of Stabia, where they met with another of Pliny's friends, Pomponianus. As they landed, both parties were being pelted with falling pieces of rock, which by this point covered the ground.

Pomponianus was visibly upset. Pliny, in an attempt to calm his friend by displaying his own composure, ordered his servants to carry him into the bathroom for some relaxation time. He was relaxed and happy and repeatedly told Pomponianus and his staff that there was nothing to fear; the fires on the side of the mountain were probably abandoned peasant bonfires, or burning houses left unattended. Even as the home continued to be pelted by the falling stones and ash, Pliny cheerfully ate, and then took a nap; the depth of his sleep was confirmed by the servants outside the room, who could hear the corpulent commander snoring heavily.

Eventually the rocks and debris gathering outside piled up so high that they threatened to seal the house in. Pomponianus awoke Pliny, informing him of this development and telling him they must make a decision soon. The group decided to abandon Pomponianus's villa and escape across the sea while they could; they all tied pillows to their heads to protect themselves from the falling objects and, although Pliny had slept through the night and the sun had risen, the volcanic cloud had blocked out the sun almost completely, so they needed to light torches to see as well. The party headed down to the water's edge, anxious to escape the disaster. Pliny saw the choppy, disturbed water and realized it was too difficult to navigate, so he called for his servants again to set down a blanket. The heavyset man then laid down on it for a rest, exhausted by the travel and exhibiting increasingly severe breathing difficulties, and called for some cold water to drink.

The initial, ash- and pumice-spewing phase of the eruption of Pompeii - known now to vulcanologists as the Plinian phase - was about to come to an end, and the parties of Pliny and his friend Pomponianus could sense it. Fires were drawing nearer to the town of Stabia, and the air reeked strongly of sulfur. Many of the people cried out to the gods for assistance, and others were convinced that the gods were all dead and the world was coming to a fiery end. They informed Pliny that it was time to go, and the big man struggled to get to his feet. Despite being supported by two of his slaves, he could barely stand, and almost immediately collapsed to the ground. The rest of the party, fearing for their own lives, fled.

Not long thereafter, Vesuvius exploded into two pyroclastic clouds, asphyxiating anyone left in the towns of Oplontis, Herculaneum, and Pompeii, burying the latter in over nine feet of ash, dust, pumice, rocks, and debris. There is no more mention of Pliny's friend Rectina, and it is likely that she was not rescued in time. Pomponianus and his party managed to escape the eruption, catching up with Plinia and her son - Gaius Plinius Cecilius Secundus, commonly called Pliny the Younger, and eventually reaching the esteemed position of Roman Consul, it was he who interviewed the survivors and chronicled the incident in a series of letters to the historian Tactitus. Pliny the Elder's body was discovered two days later, in the ash-buried ruins of Pomponianus's villa; it was reported that he choked on the volcanic fumes, but as no one else in his party was affected, it seems likely that he instead died of a heart attack or another weight or fitness-related malady exasperated by the choking atmosphere.

Vesuvius itself last erupted in 1948, and is today a national park. Any seismographic activity is vigilantly monitored by the Osservatorio Vesuvio, and there are numerous plans to evacuate the 600,000 or so people in its shadow.

Links and Sources:
Wikipedia articles on Pliny the Elder and the eruption of Vesuvius in 79 AD.

The letter from Pliny the Younger to Tactius is online here.

Painting of Pompeiians fleeing Vesuvius is by Peter Bianchi, from National Geographic.
Map is from NASA.

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