Seismotectonics of the Cyprian Arc

The Cyprian Arc forms the plate boundary between the Anatolian plate in the north and the Nubian and Sinai plates in the south. We examine the tectonic setting and seismic activity along the arc in light of new geodetic studies indicating relative NE-SW plate motions across the arc. The first-order tectonic variations are determined by the arc's geometry. The eastern arc, oriented subparallel to relative motion, is dominated by transcurrent tectonism. The western arc is oriented almost normal to relative plate motion and is subjected to convergent processes. Variations in the level and depth of seismic activity along the western arc suggest that the northwestern section of the arc represents a subduction boundary, whereas the southeastern section represents a collision boundary. The two tectonic domains of the western arc are separated by a NE-SW trending tear fault, which produces large earthquakes, such as the M_W = 6.8, 1996 Paphos earthquake. We compare the geometrically similar Cyprian and Hellenic Arcs and find significant differences in the rate, direction and type of convergence across the two arcs. The Hellenic Arc is subjected mainly to subduction, whereas the shorter Cyprian Arc is subjected to subduction, collision and transcurrent tectonic processes.