Holocene seismic activity of the priene–sazlı fault revealed by cosmogenic36CL, western Anatolia, Turkey

Abstract

Fault scarps in carbonates are structures well suited to36Cl analysis of paleoearthquakes to reconstruct the seismic history using cosmogenic36Cl. In this study, we measured cosmogenic36Cl concentrations in 117 samples along one of the active faults in Western Anatolia, the Priene–Sazlı Fault scarp, to reconstruct the age of paleoearthquakes along with their slip amounts, beyond the available historical and instrumental archives. Our results indicate four periods of high seismic activity on the Priene–Sazlı Fault since the early Holocene at 8.1 ± 2.0, 6.0 ± 1.5, 3.7 ± 0.9, and 2.2 ± 0.5 ka, with slips of 3.4 ± 0.5, 1.5 ± 0.2, 1.4 ± 0.2, and 1.5 ± 0.2 m, respectively. These ruptures mostly occurred as clusters of earthquakes with magnitudes of up to 6.7–7.0 during the Holocene. Estimated slip rates on the fault are greater than 0.3, 0.7, 0.6, and 1.0 mm/year from the oldest to the youngest modeled earthquakes. In addition, the long-term slip rate is 0.7 mm/year. This means that the Priene–Sazlı fault can be considered as a low to moderately seismogenic fault, based upon the recurrence interval.