Santorini
Introduction
Santorini, a volcano known for “one of the largest volcanic events on Earth in recorded history” and according to Druitt and others is “one of the most spectacular caldera volcanoes in he world”, is located between Greece and Turkey (Minoan Eruption). The map in figure 1, below, better depicts the location of the Santorini Volcano Arc. According to records and evidence, the Thera volcano erupted multiple times before an large explosion. The largest eruption damaged the island of Thera and the surrounding areas, particularly communities and farms. In more recent time, there has been some speculation that the volcano has “reawakened” since there has been “a significant seismic swarm and rapidly expanding radial deformation”, making knowledge of the volcanic history important to prevent another disaster (Doran et. al., 2009). The purpose of this paper is to look at the past eruption history and data of Santorini and use it to help the future.
Observations
Santorini, an interesting volcano, has been intriguing geologists because of its geology for many years, is located near Greece (Druitt et. al, 1999). Figure 1 gives a better sense of the location of Santorini in relation to Greece, Turkey, and the Aegean Sea. In the Aegean Sea, at the central south end, is where the Santorini Volcanic Island group is located ("Santorini"). The geological and tectonic setting of Sanorini is a continental-continental subduction zone, which is described as “complex” according to Druitt and others. Vespa and others also used the word complex to describe how Santorini is formed; they said Santorini is formed by the impact of the African and European plates crashing together in the Eastern Mediterranean.
The eruptive history of Santorini spreads across 360,000 years. The eruptions of Santorini have historically been very large and explosive over a period of tens of thousands years in-between or “smaller, more frequent dome-forming eruptions separated by as little as 14 years” (Morales, 2012). There have been a few significant eruptions, which include the large eruption mentioned at the beginning of this paper that occurred over 3,600 years ago and the most current eruption that happened in 1950 (Morales, 2012 & "Santorini"). Figure 2, above, shows the Santorini eruption of 1950, which created a small, flat lava dome that preceded a sequence of phreatic explosions ("Santorini").
The large eruption, known as the Minoan eruption, destroyed the Minoan communities on the Greek island. This was devastating and problematic for the settlements in that area. Although the explosion was one the most studied because of its large size, there is still a lot of lacking information from that eruption. The damage can still be seen today because tourist and visitors on the islands can see the eruptions characteristics, such as the deposits and thick layer of pumic an ash the cover the surface of the islands. ("Santorini"). Additionally, it is believed that the eruption changed the width and depth of the caldera.
The other minor and medium-sized explosive eruptions are the causing factor of the dark-colored islands located within the caldera. The characteristics of these eruptions include weak noises, felt earthquakes, ash plumes, steam clouds, and explosions ("Santorini").
The products of Santorini vary on the eruption types and size. Some products mentioned on VolcanoDiscovery include: phreatic explosions, lava flows, lava domes, ash-falls, and lava fountains. According to Druitt, 11 of the 12 major explosive eruptions discharged pyroclastic flows. These eruptions produced dominantly intermediate (andesitics) or dominantly silicic (dacitic or rhyodacitic) compositions (Druitt et. al.). The 1950 eruption has “small effusive activity” after the phreatic explosions ("Santorini").
Of the 12 explosions, 11 of them had pumice fall for a deposit according to Druitt and others. Other common deposits include: scoria low, base surges, agglomerate,