The November 17th, 2015 Lefkada (Greece) strike-slip earthquake: Field mapping of generated failures and assessment of macroseismic intensity ESI-07

摘要

On November 17, 2015 a strong, shallow earthquake (Mw = 6.5) occurred on the island of Lefkada along a N20 +/- 5 degrees E, east-dipping strike-slip fault with right-lateral sense of slip. The event triggered environmental effects that were mainly mapped at the western part of the island while moving towards the eastern part, the severity of the earthquake-induced failures decreased. The most characteristic geological effects that were triggered by the earthquake were slope failures including rock falls, rock slides and landslides. The spatial density of the failures follows an exponential increase with slope-angle and decreases for values larger than 55 degrees. Small-size liquefaction phenomena such as sand craters and ejection of fine-grained sand through ground cracks were documented at the coastal area of Vassiliki. The epicentral intensity was assessed based on the definitions of Environment Seismic Intensity scale as VIII ESI-07, and the macroseismic epicenter (VIII up to IX) was located at the coastal area of Egremnoi (west of Athani village, south Lefkada).