Plate motion is occurring all over the world. Plate motion is the driving force of earthquakes. Without plate tectonics, we wouldn’t have any of the landscapes we see today, including the island of Santorini.
The white double arrows on this map represent the direction of plate motion of the African plate and the Eurasian plate. The Aegean microplate is a small portion of the much larger Eurasian plate. The Aegean microplate is the area we are interested in.
Taking a closer look at the Aegean microplate shows the location of the Hellenic trench that forms when the African plate subduction under the Aegean microplate. The map also shows the location of the Cyclades, specifically Milos, Santorini, and Kos. These locations are of special interest because they are located on oblique faults. Modified from Piper & Perissoratis.
At subduction zones, the more dense plate, usually the oceanic plate, subducts under the less dense plate. This is the type of activity that is occurring at the African-Aegean plate boundary. This plate motion creates earthquakes.
Oblique faults occur when two plate are sliding past each other. This motion is represented by a peanut butter and jelly sandwich. 1) Two plates of different composition. 2) Plates are next to each other but are moving in different directions. This plate motion is represented by blue arrows. The plate motion causing stress to build between the plates. 3) An earthquake will occur when the stress becomes too much to hold. During an earthquake, one plate slides down and the other plate slides up. 4) As the plates are sliding up and down, they are also sliding side to side. This motion is called oblique slip. The oblique fault motion is what allows volcanism to occur on Santorini. For more information on volcanism, check out Tabatha, Brynn and Abigail’s blogs.
Piper, D. J.W., and Perissoratis, C., 2003, Quaternary neotectonics of the South Aegean arc: Marine Geology, v. 198, p. 283
Presley, E., 1957, All Shook Up.