Holocene record of slip-predictable earthquakes on the Kenchreai Fault, Gulf of Corinth, Greece

Abstract

We present the Quaternary slip history of the Kenchreai Fault, Gulf of Corinth, based on geomorphological, palaeoseismological, geo-archaeological data and literally determined events. We also applied a series of geomorphic indices such as the hypsometric curve, asymmetry factor, the stream length-gradient index (SL), the valley floor width to valley height ratio (Vf), the drainage basin shape (Bs) and the mountain-front sinuosity (Smf), in drainage basins flowing perpendicular to the fault. These indices are representative for longer time period and are analyzed as follows. Values of SL are relatively high close to the fault trace. Smf values range from 1.01 to 1.85. Vf mean values range between 0.29 and 1.07. Bs values range from 1.16 to 4.78. Lateral fault growth was likely achieved by propagation primarily towards east while its western end appears to act as persistent barrier. The Holocene palaeoseismic history of the fault investigated by a palaeoseismological trench and 14C dating of ten samples suggest four linear morphogenic earthquakes in the last 10 ka. The Kenchreai Fault displays a Holocene slip rate in the order of 0.15 mm a−1 and a recurrence interval ranging between 1300 and 4700 years. Thus the fault is classified as a fault of moderate activity with moderate to well-developed geomorphic evidence of activity and an overall slip-predictable earthquake model.