The professor of Geology and Natural Disaster Management, as well as the president of OASP, Efthymios Lekkas, speaking on an ERT show, said, among other things, that "Santorini always has a high landslide risk in the caldera.
What does this mean? It means that many landslides occur, and these many landslides are due to the steep morphological gradients that characterize Santorini and the continuous repetition of rocks, lavas, and pyroclastics.
Pyroclastic rocks are easily dissolved, while lavas are probably the hardest rocks that exist. So, when a pyroclastic rock is under a lava volume, it slowly erodes, causing the overlying lava to lose its support. This develops in Santorini, almost throughout the caldera."
Mr. Lekkas added that "in 2011, we had the loss of people in Oia due to the occurrence of a landslide, and in general, the risk is high. But the exposure of people is also very high because we have a high population density in the summer months. Therefore, it creates a problem, which, of course, we have pointed out for several years.
The necessary measures have been taken. In 2010, major works were carried out in Santorini to deal with the landslides in Athinios, the old port, and Oia. But as you understand, all this is in a dynamic process of evolution […] As I told you, things are not prohibited. I have already spoken with the Mayor and the Regional Governor, Mr. Hatzimarkos, in the South Aegean, and we have discussed some future actions that should be taken immediately to reduce the risk, which I repeat is of particular importance because Easter is also the beginning of the tourist season."
Thirasia is a Cyclade island located to the west of Santorini, about one mile from Amoudi of Oia. It was a small part of the western coast of prehistoric Stroggili and is thought to have been cut off and created during the great eruption of 1600 BC.