Santorini

Santorini is a volcanic island, the southernmost of the Cyclades. The island was formed from the sometimes explosive outflows of the least three separate volcanoes connected by a common magma chamber. In about 1450 B.C. (the exact date is debated), Santorini was effectively destroyed by a cataclysmic eruption, culminating in an explosion which pulverized about 56 cubic miles of the island. (The eruption of Mt Saint Helen’s, Krakatoa and Mount Mazama (Crater lake) were minor in comparison.) The resulting ash cloud and tsunami devastated civilizations in the southern and central Aegean Sea, including the Minoan civilization in Crete. Significant ash deposits have been identified as far away as eastern Turkey and Egypt.

Today while traversing the island to the towns of Oia and Fira, we saw the rapidly eroding walls of the caldera, whose layers reveal Santorini’s explosive past. Several deposits of ash (one more than 10 meters thick) provide evidence of at least two significant eruptions prior to the 1450 BC blast. We saw many mines dug into the sides of the caldera into these deposits, the material extracted was used to provide pozitlan for the construction of underwater portions of the Suez Canal. The mine openings, support structures and shipping platforms are still clearly visible.

Presently, Santorini is classified an active volcano, with two small islands currently being formed in the caldera. Two significant earthquakes occurred in the 20th Century, the more severe in 1956, which caused significant damage to the towns dotting the island. The islands are being closely monitored for future seismic activity.