Slip rates on the Helike Fault, Gulf of Corinth, Greece: new evidence from geoarchaeology

Abstract

AbstractPalaeoseismological and archaeological analysis of a trench enabled us to estimate the Holocene slip rates on the East Helike Fault, flanking the south‐western Gulf of Corinth. We recognized two major fault strands within the trench: the ‘north fault’ controls a succession of three colluvial wedges and the deposition of a 2.7 m thick sedimentary sequence. The ‘south fault’ controls the deposition of a 2.9‐m thick brownish‐red colluvium. Based on colluvial stratigraphy, radiocarbon dating of the sediments suggests that the slip rate was c. 0.3 mm yr−1 from 10 250 to c. 1400 bp, when it increased dramatically to c. 2.0 mm yr−1 after a strong earthquake event near 1400 bp. The faster slip rate evidently increased the sedimentation rate.