Constancy of strain release rates along the North Anatolian fault

The behavior of major active faults at various temporal and spatial scales is one of the most fundamental, unresolved problems in modern tectonics. Determining the degree to which fault loading and strain release rates are constant (or non-constant) and documenting past earthquake occurrences are key approaches for understanding this phenomenon. I have employed geomorphic mapping, Quaternary dating methods, and paleoseismic trenching to generate fault rate and earthquake age data that help provide a better understanding of the North Anatolian fault's behavior in various temporal and spatial scales. Specifically, I mapped offset geomorphic markers along the North Anatolian fault and used cosmogenic nuclide (10Be and 36Cl) and radiocarbon (14C) dating methods to constrain the ages of these features. Using these and other published data, I also constructed one of the first compilations of strain-release rates for the North Anatolian fault. My compilation of these rate data reveals a constant slip rate of ∼15-20 mm yr-1 over time scales of 103-105 years. This result, however, is slower than the geodetically constrained slip rate of 25 +/- 2 mm yr-1 [Reilinger et al., 2007], possibly indicating a strain transient. In addition to my slip rate studies, I performed paleoseismologic trenching on the eastern part of the North Anatolian fault at the village of Lorut. My results from this site demonstrate a relatively regular occurrence of large earthquakes along this stretch of the North Anatolian fault. I attribute the relatively constant strain release rates and regular earthquake recurrences to the mechanical simplicity of the Anatolian-Eurasian plate boundary in northern Turkey, which is dominated by the slip on the structurally mature North Anatolian fault.