Understanding the 13 May 1995 western Macedonia earthquake: A paleoseismological approach

• Published in: Journal of geodynamics 1998-10, Vol.26 (2), p.327-339
• Main Authors: Chatzipetros, Alexandros A., Pavlides, Spyros B., Mountrakis, Demosthenis M.
• Format: Article
• Language: English
• ISSN: 0264-3707
• DOI: 10.1016/S0264-3707(97)00069-0

Paleoseismological research by means of trenching in the area that was affected by the Kozani-Grevena strong ( M s = 6.6) earthquake sequence, revealed evidence for past reactivations of the same seismogenic fault. Five trenches were excavated along the Palaeochori-Sarakina part of the fault, in which three surface faulting paleoevents were identified at ca. 8.97, 36.7 and 72.5 ka BP (TL dates). Recurrence interval based on these datings is about 30 ka, which is very long, verifying the ‘low seismicity’ status of the area. On this basis, the 1995 earthquake was an out of sequence event, because the elapse time since the last major event is 8.97 ka instead of 30. Assuming a constant rate of strain accumulation, this would also explain the small amount of surface displacement that was observed during the 1995 earthquake (maximum 18 cm, usually up to 10 cm) in respect to the displacements observed in the trenches (> 25 cm) for previous paleoevents.