M 6.5 - 19 km SSW of Lefkáda, Greece

Tectonic Summary

The November 17, 2015 M 6.5 earthquake northwest of Nidri, Greece, occurred as the result of strike slip faulting on or near the regional plate boundary between the Nubia (Africa) and Eurasia plates. At the location of this earthquake, Nubia converges with Eurasia at a rate of 9mm/yr towards the north-northwest. Nubian lithosphere subducts beneath the Aegean Sea along the Hellenic Arc, to the south of Crete and southeast of the November 17 earthquake. Farther west, plate motion becomes more oblique as the plate boundary rotates clockwise, until the boundary is dominantly transform in the region of this earthquake. Preliminary focal mechanisms for the earthquake indicate it occurred as the result of either northwest striking, left-lateral faulting or northeast striking, right-lateral slip. Left-lateral faulting would be consistent with the orientation of the local plate boundary, while right-lateral faulting would align with other regional, non plate boundary faults. Preliminary aftershock locations suggest rupture occurred on the right-lateral, SW-NE striking plane. Further studies will be required to determine the specific faulting structure.

The region surrounding Greece is frequently impacted by moderate-to-large earthquakes like the November 17, 2015 event, and 14 other earthquakes of M6.5 or larger have occurred within 250 km of the November 17 event over the last century. The largest was a M 7.0 in January 1983, 85 km to the south, which did not cause any known fatalities. A M 6.3 event in August 2003, just 20 km to the north-northwest, also did not result in any known fatalities, though a M 6.5 earthquake in June 1995, 160 km to the east of the November 17, 2015 event, resulted in over 20 fatalities and 60 injuries.