Abstract:

While there has been significant research on the dating of paleoearthquakes using methods such as surface cosmogenic dating, and trench-based luminescence or radiocarbon dating, this paper focuses on implementing an alternative surface dating method using a fault scarp-based optically stimulated luminescence (OSL) dating approach. Hence for the first time, we investigated the Pleistocene to Holocene earthquake cycle of the Manisa Fault, one of the dip-slip active faults of the Western Anatolia extensional province, utilizing novel OSL surface exposure techniques. In this technique, OSL bleaching profiles on the fault surface are directly related to the exposure of the fresh fault scarps that are produced by earthquakes. The results indicate that the Manisa Fault is responsible for at least six surface rupturing earthquakes since the Holocene, occurring at 154 ± 22 year (E6: LSD3), 416 ± 48 year (E5: LSD4), 1103 ± 82 year (E4: LSD5), 2067 ± 138 year (E3: LSD6), 5376 ± 48 year (E2: LSD7), and 6432 ± 218 year (E1: LSD8). Our results of the first use of this novel method on the Manisa Fault are in agreement with prior cosmogenic dating of fault scarps and trench-based paleoseismological chronological data, and we conclude that the OSL surface chronology is a promising alternative for fault scarp dating of paleoearthquakes.

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