Akademik Veri Yönetim Sistemi
JOURNAL OF AFRICAN EARTH SCIENCES, cilt.1, sa.1, ss.1-41, 2025 (SCI-Expanded)
On February 6, 2023, two destructive earthquakes and many posterior aftershocks hit the Kahramanmaraş area in the south Anatolia region. The Kahramanmaraş earthquake sequence (KMES) caused extensive damage and economic losses in Türkiye and Syria. In this study, the 3-D crustal seismic velocities surrounding the hypocentral region of the KMES are determined using a large dataset of body wave arrival times obtained from local earthquakes. To better constrain the physical properties and seismogenic behavior of the KMES source region, the Vp/Vs ratio was calculated and correlated with Poisson's ratio using the obtained velocity models. To gain a better understanding of the stress conditions and regional earthquake activity in the study area, the depth variation of the b-value was also examined. Velocity structure is generally heterogeneous with both low and high velocities at upper crustal depths. Along the East Anatolian Fault Zone and its environs, low-velocity anomalies are charted. Also, small b-values (<1.0) are estimated in the region encompassing the KMES, especially at the upper crustal depths. The KMES source zone is characterized by low b-value, low to average Vp, low Vs, and average/high Vp/Vs. Hit count rates and the resolution test show that the mapped velocity anomalies are robust down to a depth of 45 km in the uppermost mantle of the affected area. Therefore, the moderate/high Vp/Vs and small b-values at the upper and middle crustal depths along the EAFZ can reflect the next earthquake hazards of the study region. The present findings give deeper insight into the physical properties and the seismogenic potential of the crustal zones in proximity to the active fault segments of the Anatolian plateau and the northwestern part of Arabia.