A landslide occurred on Saturday, April 27, at 19:00, in the region of Therasia, near the port of Korfos. The event caused material damage and raised concerns about possible hazards linked to the island’s geological makeup despite no reports of injuries.
According to Efthymios Lekkas, professor of geology and natural disaster management who also serves as the president of OASP, Santorini has a high possibility of experiencing landslides due to three key variables:
- The island’s high morphological slopes are a significant contributor to the terrain’s instability.
- The region’s solid seismic activity is another factor making the risk even more severe.
- The unconventional arrangement of rocks, which includes volcanic lavas and pyroclastic elements that are resistant to erosion, results in an unstable foundation.
In his explanation, Lekkas stated that the usual cause of these landslides is the progressive erosion of the pyroclastic rocks underneath them, which ultimately results in the lack of support for the lava flows above them. This process is an ongoing dynamic evolution that requires continual monitoring and preventative actions because of its nature.
Santorini always has a high landslide risk in the caldera. What does this mean? It means that we have the occurrence of many landslides, and these landslides are due to certain causes. The causes are as follows: the steep morphological slopes, the high seismicity characterizing Santorini, and the sequence of rocks. It is composed of volcanic rocks, lavas, and pyroclastics in continuous repetitions. Pyroclastic rocks dissolve easily, while lavas are perhaps the hardest rocks that exist, so when a lava flow is underlain by a pyroclastic rock, it gradually erodes, resulting in the overlying lava losing support. This is the classic mechanism that develops in Santorini, almost throughout the caldera.
Efthymios Lekkas, Professor of Geology and Natural Disaster Management
Despite significant efforts in 2010 to address landslides in several different regions of Santorini, such as Athinios, the ancient harbour, and Oia, Lekkas underlined the necessity of rapid initiatives to decrease the dangers further. Given the forthcoming Easter celebrations and the imminent tourist season, when the island’s population density would significantly expand, he emphasized the critical nature of the situation, particularly in light of them.
Lekkas has already begun negotiations with local officials, including the mayor and the regional governor of the South Aegean, to plan and implement future initiatives to limit the danger of landslides occurring on the island. These discussions are a response to the catastrophe that occurred. Furthermore, by the directives of Minister Kikilias, Lekkas will travel to Santorini to evaluate the current situation and suggest immediate actions that would improve safety and readiness procedures.