Volcanism in the ancient world

Dr Robert Sturm (Austria)

In the ancient Greek and Roman world, volcanism was recognised as a divine phenomenon standing in close connection with the fire god, Hephaestus or Vulcan. Although there did not exist any term corresponding to the modern word “volcano”, people were aware of the destructive power arising from volcanic eruptions. Some early natural philosophers were already able to identify individual volcanic processes, such as lava flow and the generation of huge and extremely hot dust clouds. In the ancient Greek language, lava masses streaming downhill were simply named “rhea” (ῥύαξ or flow), whereas the Latin words “Vulcanius amnis” (Vulcanic stream), “saxa liquefacta” (liquefied rocks) and “massa ardens” (blazing mass) were used for the same phenomenon.

Volcanoes were of enormous importance for the ancient Mediterranean world, because their eruptions caused the destruction of adjacent settlements and even the annihilation of entire civilizations. According to our present historical and archaeological knowledge, three volcanoes had an immense influence on the development of Mediterranean cultures: (1) the volcano of Thira-Santorini, which left behind the huge caldera visible today; (2) Vesuvius near the city of Naples; and (3) Etna on the island of Sicily (Fig. 1).

In this article, I intend to describe these volcanoes in some detail and additionally want to provide some information on the disastrous eruptions produced by two of them. And, as we will see in the following sections, ancient volcanism had a similar impact on man and climate as well-documented eruptions of the modern times (for example, Krakatoa, Mount St Helens and Pinatubo).

The eruption of the Thira-Santorini volcano (sixteenth century BC)

The island of Santorini is situated in the centre the Greek Cyclades islands and once was marked by the activity of a huge volcano, which erupted in the Middle Bronze Age, sometime between 1650BC and 1550BC. During this natural disaster, the settlement of Akrotiri was completely covered in pumice and volcanic ash, thereby preserving the ancient urban structures, which can still be seen and visited today.

According to the results of recent scientific studies, the cataclysmic eruption of the island’s volcano was preceded by earthquakes reaching a magnitude 7 on the Richter scale. These seismic shocks caused the destruction of the town and the creation of 9m-high tsunami. The eruption itself occurred some days later and entailed the release of about 15 billion tons of magma, accompanied by an enormous cloud of volcanic ash. The disaster was not only responsible for the extinction of Akrotiri, but also for the destruction of Trianda on Rhodes and cities along the northern coast of Crete. Current scientific investigations suggest that the eruption of the Thira-Santorini volcano also caused the fall of the Minoan palace era and initiated Mycenaean imperialism in the Aegean region.

Based on findings of numerous volcanologists, the Thira-Santorini eruption has to be seen as the largest volcanic event of the last 10,000 years. Compared to Krakatoa, which is considered the second largest eruption witnessed by man, the Thira-Santorini disaster was four or five times more powerful. The Mediterranean volcano exploded with the power of several hundred atomic bombs detonating within a fraction of a second. As a result of this enormous eruption, a huge caldera with a diameter of 10km to 15km was formed (Fig. 2).

The eruption of the Vesuvius (79AD)

Mount Vesuvius, located in the bay of Naples in south-western Italy, has become one of the most famous volcanoes in the World as a result of its eruption in the year 79AD. This caused the complete destruction of the city of Pompeii and the town of Herculaneum. The mountain has an altitude of about 1,300m and was formed as a result of the subduction of the African plate under the Eurasian plate.

As reported in ancient Latin sources, in the high summer of the year 79AD, strange things began to occur – such as dead fish floating in the River Sarno, the inexplicable drying up of springs and wells and the wilting of vines on the slopes of the Vesuvius. Additionally, the number of rather weak earthquakes began to increase continuously. On the morning of 24 August, a tremendous explosion signalled the beginning of the eruption, which seemed to be quite harmless in its initial phase, but became much more dangerous at midday. At this time, a bigger explosion blew off the entire cone of the volcano and caused a mushroom cloud of pumice particles to rise 43km into the sky.

When the volcanic ash rained down on Pompeii, it formed a dense and muddy cover measuring several centimetres in thickness. From this point on, people recognised the seriousness of their situation and tried to flee the town. In the late afternoon, another massive explosion filled the air, resulting in the release of another column of ash. This cloud contained much heavier material and smothered the town under its enormous weight (Fig. 4). Under metres of thick layers of mud and stones, most of the buildings began to collapse, killing the few survivors that had been left huddled near walls and under stairs for greater protection.

In the late evening, the remaining ash cloud above the volcano collapsed under its own weight and overran the city of Pompeii in six devastating waves. The super-heated air immediately burnt the lungs of the remaining citizens and literally baked the bodies of men, women and children. Finally, the corpses mummified in this way were buried under a thick layer of volcanic ash (Fig. 5).

After the natural disaster, Pompeii fell into oblivion until the middle of the eighteenth century, when archaeological exploration of the ancient site began. Excavations have been ongoing ever since and will be continued in the future, because Pompeii represents a fantastic window into the past.

Ancient activity of Etna on Sicily

Mount Etna represents a so-called composite volcano, which is located on the north-eastern edge of Sicily and measures 3,279m in height. The total size of the volcanic area amounts to about 1,000km². There are numerous towns and villages surrounding Etna, among which Catania on the south-eastern slope of the mountain is the largest settlement, all taking advantage of the fertile volcanic soil on the slopes. The volcano has been spewing lava for thousands of years, with the first recorded eruption dating to the year 475BC.

In the ancient Greek and Roman world, Mount Etna played an important role in several respects: it was considered the home of Hephaestus and the workshop of Cyclops. As reported in ancient text sources, in 396BC, the volcano was marked by such an enormous eruption that it stopped the Carthaginian army from occupying Catania, which saved the lives of many Greeks. During an eruption in the year 122BC, Catania became covered by such a thick layer of volcanic ash that the ruling Romans granted the city a tax break, until the urban infrastructure and architecture had been fully repaired.

The most disastrous eruption began on 8 March 1669, when Etna rumbled for three days and destroyed Catania with enormous quantities of lava. According to current estimates, over 18,000 citizens perished during this catastrophe. Today, Mount Etna still ranks among the most active volcanoes in the world and thus represents a preferential research object by volcanologists.

Some concluding remarks

In earlier contributions, I focused on the mines and artwork of the ancient Greek and Roman cultures. In those articles, I demonstrated that the techniques of quarrying and mechanical treatment of the stony material passed through a continuous evolutionary process, which was also responsible for the great success of these civilizations. However, although the Greek and Romans became temporary rulers of the ancient world, they were powerless in the face of natural disasters, of which earthquakes and volcanic eruptions were of the greatest significance. Many people living in the vicinity of a volcano, who were taking advantage of the fertility of the soil and the abundance of minerals (all the result of the volcano itself), were not aware of the imminent danger and thought that they would stand under protection of the gods. When they finally recognised the hopelessness of their situation, it was too late to escape death.

Further reading

Chester, D. K., Duncan, A. M., Guest, J. E. & Kilburn, C. R. J.: Mount Etna: The Anatomy of a Volcano. Chapman and Hall (1985).

Friedrich, W. L.: Fire in the Sea – The Santorini Volcano: Natural History and the Legends of Atlantis. Cambridge University Press (1999).

Sigurdsson, H. & Carey, S.: The eruption of Vesuvius in AD 79. In: Jashemski, W. M. F. & Meyer, F. G. The natural history of Pompeii. Cambridge University Press (2002), pp. 29-36.

Sturm, R.: Cameos from ancient Greece and Rome: small but precious treasures. Deposits Magazine, 34, 44-46 (2013).

Sturm, R.: Tauern gold: the history of gold mining in the Central Alps. Deposits Magazine, 37, 39-40 (2014).

Sturm, R.: Mining in ancient Greece and Rome. Deposits Magazine, 41, 43-45 (2015).

Sturm, R.: Marble from the Isle of Paros – a tour of the ancient quarries. Deposits Magazine (2017).

Sturm, R.: Roman quarries in Austria and Germany – a short sight-seeing tour. Deposits Magazine (2017).