Seismotectonics of the easternmost Cypriot Arc: An active plate boundary

Abstract

The easternmost segment of the Cypriot Arc crosscuts the seabed between the Syrian and Cypriot coasts. This arc represents the plate boundary between the Anatolian plate and the Sinai subplate. The current study aims to analyze and integrate earthquake, tectonic, bathymetric and geophysical marine data of this segment for assessing its seismotectonic setting. Bathymetry of the studied area has provided a detailed chart of the seabed and permitted tracing of the main faults. The seismic activity has been characterized as moderate, where 306 earthquakes with mb ≥ 3.0 have been recorded during the period 1894–2017. The fault plane solutions have been examined in details for identifying the operative stress field. The focal mechanisms reveal that the thrust faulting events are dominant in the south of Cyprus; the strike-slip events appear eastward; and the normal faulting events are located in the northeast termination of the Cypriot Arc. This observation can be interpreted as an evident change of tectonic regime along both Latakia and Kythrea faults. Spatial variations of the maximum horizontal compression stress (SHmax) direction have been observed with relative conformity across the Cypriot Arc. These variations of the present-day stress field could be related to the northward movement of the Sinai subplate, whereas its various directions could be produced by a wavy complex plate boundary of the Cypriot Arc. The finding contributes to tsunami hazard assessment for the easternmost Mediterranean Sea.