Our class has been in awe of Santorini ever since the first time we laid eyes on this breathtaking Mediterranean getaway that is considered the most beautiful island in all of Europe. Most people that travel to Santorini also enjoy it’s beauty, but it was us ‘Pioneers of NAU In Greece’ (a title given to us by our volcanologist professor) that were fully able to appreciate it’s uniqueness through the study of it’s past, present and future Geologic timeline. Whether it’s viewing the powerful drop-off of the submerged caldera floor through a snorkeling mask or taking a guided boat tour to the tectonically heated hot springs; our magical experiences our always tied in with our studies. For me personally, one of the most jaw-dropping experiences was traveling to Red Beach on the southern peninsula of Thira and viewing a seemingly perfect eroded cross-section of a roughly 500,000 year old cinder cone volcano.
Humans have learned to use rocks for many different purposes in life, such as for tools, jewelry, and even counter tops, but what intrigues me is the observation and inference of rocks that tell a story of the past. Even after taking multiple geology classes at NAU, I have only recently learned about one important characteristic of volcanic deposits that provides information on how an eruption occurred thousands of years ago; a block sag. The geologic definition of a “block” is defined as an angular piece of lava (larger than 64mm) that was ballistically ejected from a volcanic vent. On the other hand, a block sag is a depressed or indented section of rock strata that was created by a ballistically ejected angular fragment of a volcano during an explosive eruption. The blocks that we’ve seen here on Santorini have had a wide variety of sizes, ranging up to two meters. We found an impressive two meter block on the edge of Cape Akrotiri, which is on the southwest tip of the island. (Observation Point 9 on the map below)
Evidence of wine production in Santorini dates back to 3500 B.C., but it was not until after the Caldera-forming Minoan eruption 20 centuries later that gave the island it’s unique environmental and geological characteristics that make the wine cultivation so unique. The rich soil that fuels over 10% of the island’s economy is known as “Aspa”, which is mainly composed of the porous volcanic rock called pumice, along with the volcanic ash from this explosive eruption.(1) The lack of clay in the soil make Santorini one of the few areas in the world not affected by the devastating Phylloxera pest, who depends on a high clay content to survive. Without the volcanic/tectonic influence on Santorini’s soil, wine cultivation on this Mediterranean island would have never made it through the 19th century. (3)