Hello! My name is Abigail and I’m majoring in Criminology but love learning about the Earth. That is why I came along with my Geology teacher to Greece! Santorini is full of geological hazards that scientists have to figure out and locate where these certain hazards may occur, such as volcanoes.
The Aegean Sea is comprised of faults and many plates but Santorini was created by the African Plate (oceanic crust) subducting beneath the Eurasian Plate (continental crust). In the black box is where the two plates meet. The Hellenic Trench is where the subduction from the plates begin and cause volcanism to occur. The black arrows depict the direction of Plate motion where as the lines with empty triangles on top show trenches. The process of how a volcano begins interests me because I’ve never thought of how an island appears or what it is made from. I thought islands were there and always have been but volcanism and plate tectonics create what we see today, including Santorini. Modified from Zuckerman, 2011.
If looking at Santorini, the oceanic subducting crust is the African plate and the continental crust is the Aegean Microplate. When the oceanic crust goes beneath the continental lithosphere, it builds up pressure and releases water into the surrounding rock. Water that is released into the rock creates the rocks melting temperatures to lower. Since melting temperatures are decreased, the rock is able to become magma and move towards the surface. Magma moves towards the surface because it is less dense than the surrounding rock. My favorite part about Santorini is learning how it once was a large volcano made up of many volcanoes. This satellite image only depicts one volcano that used to make up the massive caldera forming volcano island. The cinder cone in this picture is now half gone due to erosion and landslides. It’s estimated full size is represented by the yellow dash lines and the white circle depicts where the vent would have been. Modified from Friedrich, 2009.
While at Red Beach I captured this photo displaying the inside of a Cinder Cone volcano previously shown in the satellite image. This volcano is believed to have erupted 553 ka +/- 10 ka. The white arrows show where there is high risk for another landslide to happen. Since the eruption, the sides of the volcano have been breaking away into the Aegean Sea. I personally would not swim or walk close to the outcrop because of the serious risk of a landslide occurring. Many people who visit aren’t aware and it boggles my mind how many tourist are allowed to see the volcano up close and contribute to its erosion process.
A caldera forming eruption or volcanic activity happens every 200ka for Santorini. Although the Cinder Cone that makes up Red Beach is no longer active, the small island in the middle of Santorini is. Nea kameni had mafic lava flows breach the surface in 1950. This indicates that the magma chamber beneath the surface still contains magma and that the volcano will continue to grow. Eventually the island will have another caldera forming eruption but not for hundreds of thousands of years. It’s cool to see that across the world there are the same type of volcanoes as there are back at home in Arizona. Even though there are the same types of volcanoes, they occur because of different reasons. This trip to Santorini has opened my eyes and has made my brain hungry for more information about the Earth.
Friedrich, W.L., 2009 Santorini – Volcano, natural history, mythology: Denmark, Aarhus University Press, 133 p.
Zuckerman, W., 2011, Turkey earthquake reveals a new active fault zone. Newscientist.com. (Accessed June 2019).