Hi everyone! My name is Petra and I will be leading you on a tour of Santorini, an island in the Aegean Sea with an explosive past. I’ve included a photo of myself above so you will recognize me as we go exploring. Let’s begin by looking at the different types of volcanoes!
The photo above shows the six different types of volcanoes that can form. Silica is an oxidized silicon compound. Some form from mafic magma, which has a low silica content and low viscosity, meaning the magma will flow like oil, while others form with felsic magma, which has high silica content and high viscosity, meaning the magma will flow like peanut butter. While all of these volcanoes are unique in their own ways, they can all occur at the same location.
The map above shows a satellite view of the five islands of the Santorini Archipelago. Currently, only Nea Kamina is an active dome volcano. These islands, located 300 km from Athens, were formed by a series of violent eruptions.
We all recognize this photo, and we have probably all drawn it before. However, as we saw two photos ago, there are more types of volcanoes than this one. Santorini was created by a caldera forming event, which happens when all the volcano types build in one place and the magma chamber feeding these volcanoes empties over multiple eruptions. The volcanoes essentially blow themselves up until all that is left is a depression in the landscape, called a caldera.
This image helps us understand how all the volcanoes came to be. The African Plate, located to the south of Greece, is subducting, or going under, the Aegean Plate, which is a small piece of the greater Eurasian Plate that Santorini lies on. Simply, this allows volcanoes to build.
The image above shows the volcano types and how they form a caldera. When one volcanic vent erupts, the magma chamber empties and the ground collapses, creating a caldera. This is what happened in the Santorini complex, leaving the geography that we see today.
Now that you all have a better understanding of how the Santorini complex was formed, I’m going to go enjoy the volcanic rock beaches and cool, clear water!