Landslide Induced Tsunami Hazard at Volcanoes: the Case of Santorini

Abstract

The destructive tsunami on 22 December 2018 due to the flank collapse of the Anak Krakatau volcano was a bitter reminder of large tsunami risks and of the shortcomings of the existing tsunami warning systems for atypical sources (tsunamis generated by non-seismic and complex sources). In the Mediterranean, several tsunamis were generated by landslides associated with volcanic systems in the past.The volcanic unrest experienced in 2011–2012 on the Santorini volcanic island in the Southern Aegean Sea pointed out the need to identify and quantify tsunami hazard and risk due to possible flank instability which may be triggered as a result of volcanic unrest or nearby seismotectonic activities. Inspired from this need, in this study we examined three possible landslide scenarios in Santorini Island with tsunamigenic potential. The results show that the scenarios considered in our study are able to generate significant local tsunamis impacting Santorini and the nearby islands, as well as producing significant impact along the coasts of the Southern Aegean Sea. While maximum tsunami amplitudes/arrival time ranges are 1.2 m/30-90 min for locations in the Greek-Turkish coasts in the far field, they are in the order of ≈60 m/1-2 min for some locations at the Santorini Island. The extreme tsunami amplitudes and short arrival times for locations inside the Santorini Island is a major challenge in terms of tsunami hazard warning and mitigation. As an effort to address this challenge, a discussion on the requirements for local tsunami warning system addressing atypical sources in the context of multi-hazard disaster risk reduction is also provided.

Utilizing Geographic Information Systems to Zone Landslide-Prone Areas for Urban Development in the Kandy Municipal Region, Sri Lanka

“…Provide advance notices and warnings to the residents of the area about landslide hazards and make agreements with them (Necmioglu et al, 2023). To construct buildings in this area, only engineers in the field of engineering who have the experience and knowledge to design buildings according to the landslide area should be allowed to carry out construction activities in this area (Allstadt et al, 2022).…”

Introduction to “Sixty Years of Modern Tsunami Science, Volume 2: Challenges”

“…Landslides associated with volcanoes have generated tsunamis in the past, making it necessary to identify and quantify tsunami hazards and risks due to possible flank instability. Necmioglu et al ( 2023 ) examine three possible landslide scenarios with tsunamigenic potential for Santorini Island. Their results show that these scenarios could generate significant local tsunamis with extreme amplitudes and short arrival times to Greek and Turkish coasts, making warning and mitigation challenging.…”