There are groups of tourists who strive for adventures and prefer to spend their holidays exploring caves and even volcanoes! Thousands of tourists flock to the Greek islands in the summer not to enjoy the sun and sea,bur rather to experience the thrill and chill of the so-called volcanic-geologic tourism. Others take advantage of Greece's active volcanoes and enjoy the hot springs,after all Greece has about 752 of them!
Greek volcanoes are part of the "Aegean Volcanic Arc", which is caused by the subduction of the African tectonic plate under the Eurasian plate.
As you all probably already know, the most recent volcanic eruption in Greece was Santorini in 1950. Santorini erupted in 1600 BC and buried the city of Akroteri and possibly gave rise to the legend of Atlantis.
Three islands remained after the eruption - Thera, Therasia, and Aspronisi.
Santorini caldera has a diameter 11 km N-S and 7.5 km E-W, with a depth of 390 m in the north. The 1950 eruption of Santorini produced a lava dome, lava flow, and explosive activity.
In January 2011 Santorini started to wake from 60 years of inactivity. The episode began with a seismic swarm and radial deformation of the volcano. The unrest has been interpreted as radial inflation of the volcano by 5-9 cm by a magma source, 4 km below the northern half of the caldera.
Another active volcano is found on the 8 km-wide island of Nisyros which is located at the eastern end of the Hellenic island arc, 340 km SE of Athens. Nisyros is part of the Kos-Yali-Nisyros Volcanic Field in the SE part of the Aegean Sea. The Hellenic Volcanic Arc is a magmatic expression of the active northeastward-directed subduction of the African.
Historical activity of Nisyros volcano produced phreatic eruptions in the caldera. Currently fumarolic activity occurs in the caldera, and hot springs are found on the coast. The volcano has erupted at least 13 times during recorded history.
In January 2003 the crater was declared off limits due to increasing temperatures and growing surface cracks.
Interestingly, both the Santorini and Nisyros volcanoes are under constant observation from special stations, and the data is analysed on a 24-hour basis. Also, it is good to know that the volcanoes on these two particular islands are considered to be the largest in the Mediterranean.
Volcanos also exist on Milos island and in Sousaki and Methana. Historic magmatic eruptions have not occurred at Milos Island. The most recent magmatic activity consisted of two large explosive phreatomagmatic eruptions that produced Trahilas and Fyriplaka tuff rings 380,000 and 90,000 years ago.
Loutra Methana is located at the southern end of the town of Methana, and comprises a group of springs issuing from fractures of the Asprovouni lime stones close to the coast. They are hydrogen sulphide springs and are used as a thermal bath by a nearby hotel. The estimated total water flow of the spring is several tens of litres per second.
All of the above areas are considered "active", a classification of any volcano that has erupted in the last 10,000 years.