Variation of Seismogenic Depths and Thickness in Iraq

Seismic crust thickness, an engineering feature associated with the strength properties of the crust and earthquake risk by adding thermomechanical properties, is an alternative to the thickness of the crust. This study aimed to detect the seismicity onset depth (D5), seismicity cutoff depth (D95), and seismic thickness in Iraq. In this study, we utilized the earthquake focal depths data in Iraq to determine the depth at which 5% of seismicity occurs (D5) and the depth at which 95% of seismicity occurs (D95). The Seismic thickness is the disparity between seismicity cutoff depth and seismicity onset depth. The ranges for seismicity cutoff depth, seismicity onset depth and seismic thickness are 0.9-6.2 km, 14.3-38.95 km, and 11.6-36.9 km, respectively. The CV and ANOVA data results demonstrate statistically significant differences throughout the studied area. Observed variations in the results of the study indicate a clear regional diversity, which reflects the different geological and tectonic conditions. The results referred to a notable inverse correlation between earthquake density and D95 depth, and this correlation suggests that a thicker Seismogenic crust exhibits greater strength and resilience to minor magnitude earthquakes compared to a thinner seismogenic crust.