Evaluation of active faulting and earthquake secondary effects in Lefkada Island, Ionian Sea, Greece: an overview

Based on neotectonic mapping, analysis of active deformation through tectonic data and the Coulomb stress changes caused by major earthquakes, the active faults in Lefkada Island were evaluated. Descriptions of historic and recent earthquakes were also taken into consideration as well as the seismotectonic data concerning the last strong seismic event of 2003. According to detailed field observations, among the active and neotectonic faults that have been identified, regarding seismic hazard, the most important can be considered the Athani fault. It is running parallel to and near the west coast and shows marked similarity with the northern branch of the offshore transform fault of Kefalonia-Lefkada. These two dextral strike-slip faults exhibit same structure and state of stress as well. Moreover, the Coulomb stress changes associated with the 2003 earthquake, well correlated with the spatial aftershock pattern, are positive in the area of the Athani fault. Attention has been also focused on the geologic hazard in relation to earthquake associated phenomena, such as surface rupturing, landslides and rockfalls, liquefaction and tsunamis. The fact that surface deformation is repeated in an identical way during past and recent earthquakes provides a great advantage for the seismic protection of the island. Copyright Springer Science+Business Media B.V. 2012