Study of the Seismic Recordings Events Close to The Derbendikhan Dam NE–Iraq

Abstract

In this study the seismic recordings of the recorded events by the installed seismometers in the close proximity to the Derbendikhan dam were analyzed. High resolution data logger instruments were recorded hundreds of earthquakes during February to November 2014. Twenty earthquakes were used for further processing that covered the studied area and surroundings. The analysis of the arrival times and amplitudes of the body waves from different azimuths within optimal range of frequencies from (3 to 750 Hz) had been performed. The waveforms were utilized in determining the various source parameters including location, focal depth and magnitude. Epicentral map was drawn which depicts the epicentral distances of the events from the source. The estimated crustal structure below the studied area reveals that the seismic activities were occurred in the upper part of the crust depths less than (18 km). The magnitude values of the detected earthquakes striking the area were between (2.2 to 5.5). Furthermore, the seismic activities of the study area were possibly associated with the relative movements of the active tectonic plate boundaries as well as due to the increasing and decreasing of the water level of the reservoir. The resulted average values for the P-wave and S-wave velocities were (7.45 km/sec) and (3. 39 km/sec) respectively.