I N T R O D U C T I O N  -  S a n t o r i n i  V o l c a n o

Thera, Santorini, Greece
View of Fira, Santorini's main town on the caldera rim.

Volcano number: 0102-04 (according to Volcanoes of the World, 1981 edition)
summit elevation: 565 m
location: 36°25'N, 25°25'E


Thanks to its extraordinary beauty, Santorini is one of the major tourist attractions of Europe. With its marvelous climate and perfect observation conditions, its prominent caldera it is also an eldorado for volcanologists.

Santorini's volcano
The island group of Santorini is the most well-known and active volcanic centre of the Hellenic Volcanic Arc in the south Aegean Sea. It is a complex stratovolcano with a large caldera created by several large explosive eruptions. The different products of ca. 2 million years of volcanic activity have accumulated around a small non-volcanic basement, that once formed a small island similar to the other cycladic islands. Most of the volcanic layers are visible in the multi-colored sequences of the impressive steep inner walls of the caldera, striking the visitor who reaches the island by boat.

The Minoan eruption
The most recent large eruption -
the Minoan eruption - occurred in the late Bronze Age at around 1640 BC and devastated the Eastern Mediterranean. It was one of the biggest known volcanic explosions in younger time. Its deposits form the characteristic, tens of meters thick layer of white pumice and ash that blankets almost the whole of the island group. (Unbelievably, despite its abundance, pumice is sold in Fira and Oia as tourist souvenirs...)

The Minoan eruption destroyed a rich and highly developed economic and cultural centre of that time. Since 1969, intense archaeological excavations have brought to light an important Cycladic town which had been buried beneath the Minoan ash-layer for almost 4000 years. Although it appears that people had time to evacuate their island in time before the eruption, carrying most of their goods with them, the findings from Akrotiri are impressive: especially, they include well-preserved and magnificent wall paintings, ceramics and other objects. Thanks to the work of numerous archaeologists, a new light was thrown on an important prehistoric period and culture. The spectacular discovery even induced continuing speculations that relate the volcanic destruction of Santorini to the legend of the sunken Atlantis. (for a more detailed treatment of this subject follow this link)

The awakened interest on this peculiar island triggered an intensive research, not only among archaeologists, but also and in particular among volcanologists. Few volcanoes have been studied as intensively as Santorini. So far, three large international congresses only about Thera ("Thera and the Aegean world") and numerous workshops, field-trips etc. have been held on Santorini.
Together with Etna (Italy), Piton de la Fournaise (Réunion, France), Furnas (Acores, Portugal) and Teide (Gran Canaria, Spain) volcanoes, Santorini was chose as one of 5 European volcanoes where research had been focused during a special research project titled "The European laboratory volcanoes", initiated and supported by the European Commission.

Why "Decade Volcano" ?
The international volcanological organization
IAVCEI nominated 15 volcanoes "Decade volcanoes". All of them present a potentially high risk and/or are specially connected to human histry of the world: Avachinsky-Koriaksky (Russia), Colima (Mexico), Etna (Italy), Galeras (Colombia), Mauna Loa (Hawaii, USA), Merapi (Indonesia), Niragongo (Congo), Rainier (USA), Sakurajima (Japan), Santa Maria/Santiaguito (Guatemala), Santorini (Greece), Taal (Philippines), Teide (Tenerife, Spain), Ulawun (Papua New Guinea), Unzen (Japan), Vesuvius (Italy). 
The aim the Decade Volcanoes programme was to direct attention to this selected number of active volcanoes and to encourage research and public awareness. By this, the understanding of the volcanoes and the hazards posed by them has been greatly improved during the past years.

Is Santorini an active volcano?
Yes. Although at present dormant, Santorini has been active several times in historic time. During the past time span elapsed since its last major explosive eruption (in about 1640 BC) numerous minor and medium-sized, mainly effusive eruptions have built the dark-colored lava shiels of
Nea and Palea Kameni inside the caldera. Their first appearance was witnessed and reported by Greek and Roman writers. The last eruption occured in 1950. At present, only fumarolic activity, mainly inside the recently active craters, which are easily vistited on a daily basis by hundreds of tourists during the summer season from May to October.

Santorini's beauty
On few places in the world the relation between volcanism and human life has been as intense as on Santorini. The particular conditions developed an outstanding cultural and artistic style that dates several thousands of years back. Many things could be mentioned here, but one is (in my opinion) outstanding: Santorini's architecture.
Its origins are found in the simple technique of excavating the light and easily removed pumice and the necessity to collect rain water. The special properties of the volcanic ash allow to build easily water-proof cisterns and vaults. Also, protection from the strong winds, the abating light, and the inspiring, spectacular landscape play an important role. These factors have led to a perfect treatment of spaces and light, where the basic forms of the cube and the vault are dominant. The ever-varying ensembles of such simple geometric forms, full of grace and harmony, yet are always functional. Perhaps they are without equivalent, and have ever since fascinated the visitor.

A sad word:
One sad word should be said here, too. Unfortunately, a substantial part of modern building (and other) activities on Santorini have lost their original sense of proportion. Houses and buildings are growing at a monstrous speed. Mass tourism is dangerously taking over, leaving few places unaffected. Almost everywhere the results of the underlying temptation to make quick money are visible. Santorini's face is changing, and some of its natural treasures have already been lost. Santorini, once called Kallisti,- the most beautiful one-, is no longer an idyllic place, but some of its once legendary beauty and magic still remain and hopefully will be preserved for the future, too.

Click on an image to see the larger version: 

Location of Santorini.

Church in Firostefani and Nea Kameni in the background.

The historically active crater of Santorini's Nea Kameni volcano.

aerial photograph of Santorini
Aerial view of the Santorini island group (courtesy of Birke Schreiber, homepage: Santorini für Individualisten). 

Ever looked for a really good topographic map of Santorini? Here it is!

Cliffs of the caldera of Santorini
View of the 200m-high caldera cliff at Cape  Alonaki. The top layer is the ca. 40m thick Minoan pumice (BO = "Bimsstein, oberer"). The lower half of the cliff section is composed by the rests of an early stratovolcano (lavas of Cape Alonaki, ca.200-250 ka). In the middle part, the cream-white colored lower pumice series (BU1 and 2) are visible.

Fira, Santorini
Terrasses of the main town Fira. At right, Nea Kameni. In the background the south tip of the Akrotiri peninsula.

Santorini can not only offer nice beaches and a relaxing vacation...

Fumaroles on the active crater of Nea Kameni
...but it is also a paradise for walking tours. For information on organized walks and/ or geologic excursions, click here. 
*Photo from a group in May 97 at the cliffs near Akrotiri. 

Mules are still used as the main transportation method in the narrow streets of the old parts of villages.