Earthquakes and Tsunamis: Natural Hazards Over the Aegean Archipelago

Abstract

AbstractThe Aegean Sea is characterized by a strong human presence and significant achievements in all sectors of human activity for thousands of years. Its geological and geomorphological setting has been shaped by intense geodynamic processes and the current morphology is strongly related to the combination of endogenous and exogenous processes as well as the occurrence and synergy of geophysical and hydrometeorological hazards and related disasters. Despite the fact that the occurrence of destructive earthquakes and volcanic eruptions and their accompanying phenomena have led to the decline of brilliant civilizations in the past, they have significantly contributed to the adaptation to new conditions and further development and progress. This study constitutes a review of destructive earthquakes that have affected the Aegean islands from the antiquity to present and their accompanying phenomena with emphasis on the occurrence of tsunamis. The Aegean Sea is characterized by seismicity located along seismogenic zones that have hosted destructive earthquakes in the historical and recent past. Data on earthquake and tsunami occurrence in the Aegean Sea from the historical period to the present have been updated and re-evaluated. Recent events in the Aegean, including the June 2017 M = 6.3 Lesvos earthquake, the July 2017 M = 6.6 Kos earthquake and the October 2020 M = 7.0 Samos earthquake in the Northeastern Aegean and the May 2020 M = 6.2 Southern Crete earthquake along the Hellenic Arc, have been added to the pre-existing earthquake and tsunami datasets. From the record earthquake environmental effects in the Aegean Sea, it can be seen that tsunamis in the Aegean have a high potential for causing notable effects on the natural environment, the building stock and the population of the islands. From the offshore and onshore geological and neotectonic structure in the Aegean, the spatial distribution of tsunami and the intensity of the generated effects on the coastal zone, it is found that the highest potential for strong tsunami generation is located along the Hellenic Arc and in the North Aegean Through. Tsunamigenic sources are also observed in the intermediate area with different potentials for tsunami generation based on the event size, expressed in terms of intensity and the frequency of the historical tsunami events. The completeness of these lists can be considered satisfactory, attributed to the long history of the investigated geographical region, which spans thousands of years before present and is located in many areas particularly susceptible and vulnerable to earthquakes and their accompanying effects. However, the same is not applied to the quality of the relevant records and the information available from contemporary sources about events of antiquity, which can be characterized as limited.KeywordsAegean SeaEarthquakesSeismogenic sourcesTsunamiTsunamigenic zones