Thomson Holidays

The volcano history of Santorini

Holiday boat trips to the volcanic islets of the Santorini island caldera

Famous for its remarkable sunset views from impressive clifftop heights, the Cycladic island of Santorini is considered one of the most romantic holiday destinations in the world.

The island of Santorini lies in an active volcanic area called the Hellenic Volcanic Arc in the south Aegean Sea where steep, red and black cliffs surround a large sea-flooded caldera that makes it not only an island of incredible beauty but a magnet for vulcanologists.

More than two million years of volcanic activity have helped shape Santorini and it history is on open display in the multi-coloured stratified layers of the steep inner cliff walls of the caldera that strike visitors with awe as they approach the island by boat.

The Santorini caldera was born in a massive Bronze Age eruption that devastated the eastern Mediterranean around 1640 BC, wiped out the Minoan civilisation on the north coast of Crete and deposited a layer of white pumice and ash nearly ten metres thick over the whole island group.

Along with Etna in Italy, Furnas in the Azores and Teide in Gran Canaria, the eruption on Santorini is among the most studied in the world and named as one of the 15 'Decade Volcanoes' that have helped shape the history of the world.

Still active today, there have been many minor and medium sized eruptions in modern times with the last significant one recorded as recently as 1950. Lava outflows were also recorded in 1939 and 1941.

Inside the caldera is direct evidence of volcanic activity in the islets that was first reported by writers in Greek and Roman literature. The islet of Mikri Kameni appeared in a 1570 eruption and Nea Kameni (it translates as New Burnt Island) was formed in five years of volcanic activity after 1707 with many gas explosions and falls of volcanic ash.

In 1870, an eruption resulted in lava flows that united the islets of Nea and Mikri Kameni while activity between 1925 and 1928 saw the further growth of Nea Kameni and the collapse of its eastern shoreline.

Despite continuous volcanic activity, with fumeroles spurting out hot gases on a daily basis, hundreds of holiday visitors to Santorini take boats trips to the islets throughout the summer season from May to October.

The main islets of Palea and Nea Kameni sit in the in the centre of the caldera and boats arrive regularly each day bringing trippers eager for a taste of hot,barren rocks and sulfurous fumes.

Any new eruption in the islets may prove to be a double-edged sword. The small island of Santorini can accommodate more than 50,000 tourists in the summer holiday months and the villages along the caldera rim would provide a spectacular viewing platform for visitors.

However, such an tourist draw is likely to be short lived. The economic impact on Santorini would be dire should risk-averse authorities rule that the even was too dangerous for the public. Modern Santorini is almost wholly dependant on tourism and the economic fallout could be a devastating as any eruption.

Some seismic unrest was noted in 2011 and continued for more than a year. Scientists put this down to an influx of fresh magma into the chamber beneath the ilsets of the caldera. It was estimated that about 14 million cubic metres of magma entered the chamber and raised the caldera floor by 14mm.

Instruments have now been dotted at strategic points around the caldera and on the islets while an international team of scientists from Greece, France and Spain, is monitoring underwater volcanic activity very closely.