Palaeoseismic data and their implication for active deformation in Greece

Results from palaeoseismological trenching for four active faults in Greece are presented. The main target is to determine palaeoearthquake slip and slip associated with events hosted on four active faults: two of them located with the Gulf of Corinth southern part of the Greece (Kaparelli and Eliki) and two in the northern Greece within the Mygdonia and Aliakmon basins. All excavated trenches expose evidence of more than three events, thus enabling to estimate the recurrence interval (RI) of past events and the slip rate (SR) of the faults. Results for the four faults are Eliki fault: RI = 900-400 years, SR = 1.5 mm/a, Kaparelli fault: RI = 2300 years, SR = 0.3 mm/a, Mygdonia fault: RI = 900 years, SR = 0.26-0.7 mm/a, and Paleohori-Sarakina fault: RI = 30,000 (?) years, SR = 0.01-0.03 mm/a. The latter result is under question, because a different dating method was used. From all trenches the inferred earthquake magnitude is in the order of 6.5. On the other hand, both RI and SR range two orders of magnitude with faults located southerly and easterly showing shorter RI and larger SR in reference with the northwesternmost Greece. This palaeoseismological study helps us to propose a model for the behaviour of large seismogenic faults in the Aegean area in response to their geotectonic setting.