Strong Ground Motion Simulations of the 2023 Turkey–Syria Earthquake Sequence Using CGFDM3D-EQR
Authors: Xu Tianhong , Wang Wenqiang , Zhang Zhenguo 
Published: February 2023

On February 6th 2023, a large Mw 7.8 earthquake struck Turkey and Syria near the border area. Only 9 hours later, another Mw 7.5 earthquake occurred about 90 km northeast of the epicenter of the first earthquake. Up to now, the two earthquakes have killed at least 43,000 people and injured 120,000. Preliminary inversion results from USGS show that the geometric structure of the seismogenic fault is rather complex, and the rupture propagates through multiple sub-faults.Massive casualties show the necessity and urgency of an earthquake rapid emergency response system, and ground motion simulation is a key component of this system. Empirical ground-motion prediction equations (GMPEs), which are widely used, can quickly provide the distribution of ground motion and seismic intensity. Unfortunately, the calculated seismic intensity is not accurate enough due to its incomplete consideration of the earthquake source and the complicated seismic wave propagation process(Paolucci et al., 2018; Infantino et al., 2020; Stupazzini et al., 2021). In contrast, the physics-based ground motion simulation method has more advantages. In this study, we employ the USGS's finite fault inversion results as kinematic source input to model the two earthquakes' strong ground motion using the CGFDM3D-EQR platform (Wang et al., 2022). The platform can quickly run an earthquake simulation while taking into account the three-dimensional complexity of topography, underground medium, and source, providing timely reliable distribution of ground motion and seismic intensity. Preliminary findings indicate that the first earthquake's maximum intensity is XI, the second earthquake's maximum intensity is X, which is consistent with the report issued by AFAD, and that the simulated intensity's spatial distribution range is also consistent. The simulation completely considers the effects of the source, geological environment, and topography, and the seismic intensity distribution exhibits complex non-uniform properties that are closer to the reality.The rapid ground shaking simulations of the Turkey&#8211;Syria earthquake allows for the quick, accurate, and scientific assessment of earthquake damage. To reduce lives and financial losses, these results can serve as a scientific foundation and point of reference for the relevant authorities as they decide how best to respond in an earthquake and conduct out rescue operations.&#160;&#160;&#160;&#160;ReferencesInfantino M, Mazzieri I, &#214;zcebe A G, et al. 3d physics-based numerical simulations of ground motion in istanbul from earthquakes along the marmara segment of the north anatolian fault[J]. Bulletin of the Seismological Society of America, 2020, 110(5): 2559-2576.Paolucci r, Gatti F, Infantino M, et al. Broadband ground motions from 3d physics-based numerical simulations using artificial neural networksbroadband ground motions from 3d pbss using anns[J]. Bulletin of the Seismological Society of America, 2018, 108(3A): 1272-1286.Stupazzini M, Infantino M, Allmann A, et al. Physics-based probabilistic seismic hazard and loss assessment in large urban areas: A simplified application to istanbul[J]. Earthquake Engineering & Structural Dynamics, 2021, 50(1):99-115.Wang, W., Zhang, Z., Zhang, W., Yu, H., Liu, Q., Zhang, W., & Chen, X. (2022). CGFDM3D&#8208;EQR: A Platform for Rapid Response to Earthquake Disasters in 3D Complex Media. Seismological Research Letters, 93 (4): 2320-2334.