Here I am for the first time out of the country staring up at the biggest boat I have seen. Getting on the boat I was excited to get to our destination, but also to look out into the ocean and take in as much as possible. When i got to the top of the boat and saw the ocean, I could visualize the journey I was about to embark on. Once the ferry started and we got out into the ocean I could smell the cool ocean breeze and feel the chill. The water was the bluest I had ever seen and the calmest. This journey on the ferry was not only my way of getting to the island but it also served as my classroom. Abroad I got to learn about the start of Santorini. This was probably one of the only times where I got a scenery when learning. As we got closer to our destination my excitement grew and when I finally saw the caldera it was breathtaking and reminded me of why I wanted to join this program. The mixture of both being exposed to the history and looking at some of the past materials and seeing how magnificent this island is formed, was just what caught my attention.
The island of Santorini did not always look this way. The island probably began as two separate and much smaller islands composed of metamorphic and sedimentary rocks that are between 50-23 million years old . There were many events that took place over time to create the current shape of Santorini today. It is not something that happened quickly. Here is a map of what we think it looked like.
The first volcanoes to appear were the Early Akrotiri centers. This, additional island was formed 650-550 thousand years ago when magma breached the surface. The Early Akrotiri Centers were cinder cone and dome volcanoes . A cinder cone volcano is formed when gas-charged, low viscosity lava is blown violently into the air, it breaks into small fragments that solidify and fall as cinders. Dome volcanoes are formed by highly viscous magma being erupted onto the surface and then piling up. Early Akrotiri went through a volcanic uplift; this is how it was brought to the surface and able to connect with the pre-existing rock.
The next island formed north of the Early Akrotiri Centers approximately 540-430 thousand years ago and it was a child volcano (Peristeria) . Shield volcanoes form in areas where low viscosity magma comes to the surface as fast-flowing lava. The lava travels farther than other types of lava, and the steady build-up creates the shallower sides seen in shield volcanoes. After the eruption of Peristria, the land on Santorini was destroyed by its first caldera-forming eruption, approximately 200,000 years ago. The eruption was so explosive it destroyed much of the Peristria shield, and deposited a 30 m white pumice layer over the land (Lower Pumice) .
After the destruction of the island, a new shield volcano began forming approximately 76 thousand years ago (Megalo Vouno). In addition, another shield volcano (Skaros), quickly formed right next to Megalo Vouno at 67,000 years .
South of Megalo Vouno the middle pumice was the next to form approximately 60 thousand years ago. The middle pumice was right above the lower pumice area, this formed into a caldera. The caldera was a result of the eruption of the Thera volcano. A caldera volcano is generally formed by the collapse of another volcano onto itself. The emptying of the magma chamber beneath the volcano triggers the collapse. The Cape Rivas volcano took place about 21 thousand years ago, this volcano made up both the Therassia complex and the Skaros shield. This was the third caldera that had formed on the islands, this caldera was formed by the collapse of the Skaros shield volcano . The last major eruption, the Minoan eruption covered most of the islands except the pre-existing rock, occurred in 1613 B.C. This occurred because each time an eruption occurred the caldera that had already formed would fill up with magma and wait until it was time to erupt again.
Before the Minoan eruption the islands were believed to have come together to form almost a full circle that had only one opening. After the eruption the islands separated into what it is now. The last island that was to form was the Kameni shield this is dated back to 187 B.C. This occurred some time after the Minoan eruption, they have formed over the past 2000 years and are the youngest of all the islands .
The formation of Santorini has been a long process that has taken millions of years. This was not something that was able to form quickly. This is part of what makes this island so amazing. All the phases and processes that it went through to achieve what it has now, with its amazing views and remaining pieces of the past.
Friedrich W.L., 2009, Santorini: Volcano, Natural History, & Mythology, Denmark: Aarhus University Press, 312 P.