Seismicity of Iraqi western desert and surroundings: As an example of continental intraplate seismicity

Abstract

Seismicity of Iraqi western desert and surroundings was investigated using a complete and unified magnitude earthquake catalog covering the interval from 1900 to 2017. A marked rise in number of the events in the study area was observed after the year 2000 compared to the previous years. The magnitude of majority of the recorded events ranged from 2 to 3.5 Mw. The value of b-constant in frequency-magnitude relation is 0.7. The epicentral distribution shows that the western desert is aseismic to very low seismicity area compared to the surrounding regions. The epicenters were clustered in five seismogenic zones. The focal depths division of the events exhibits that majority of the earthquakes occur in the upper crust. A causal relation may be between the study area seismicity and the zones of weakness and /or stress condensation at the fault intersections.