Paleoseismology of the Ilipinar Segment (Karliova, Bingol), The North Anatolian Fault Zone

The last century earthquakes produced more than 1000 km surface rupture on the North Anatolian Fault Zone (NAFZ), which is one of the most active deformation belts in the World. Paleoseismic data from different parts of the NAFZ exposes critical information about the earthquake history of the fault zone. To research paleoseismicity of the Ilipinar Segment and relationship between the segment and last century earthquakes, two paleoseismologic trench studies performed on the Yoncalik basin, where positioned at eastern section of the Ilipinar segment. We identified two paleo-earthquakes, which correspond to BC 8500-6150 and BC 5960-4300 time intervals in the Yoncalik-1 trench. On the other hand the analyses of stratigraphy and structural features of the Yoncalik-2 trench similarly yield two events, from which the older happened before BC 6325 and the younger was between BC 6325-2105. Despite of the wide range of these intervals, both trench results are coincide within their uncertainty limits. We interpret that events in both trenches reflects the same surface ruptures. By the joint analysis of both trenches, we conclude that the most recent and penultimate events should have occurred between BC 5960-4300 and BC 8500-6325, respectively. The results from paleoseismology of the Ilipinar Segment, which constitute the easternmost part of the NAFZ, indicate that the seismic behaviour of the segment is not in accord with the general characteristic of the NAFZ. The reasons behind the disparity are considered to be related with complex fault geometry in the vicinity of Karliova triple junction and partitioning of accumulated strain on these structures.