Numerical Simulation Study on Seismic Hazard of the Malatya Fault

The double earthquakes (Mw 7.8 and Mw 7.5) that occurred in eastern Turkey on February 6, 2023, caused heavy casualties and economic losses, and significantly altered the regional tectonic stress environment. The Malatya Fault, as a key active structure in the area, has experienced a 2,500-year gap without surface-rupturing large earthquakes, raising concerns about its potential seismic hazard. This study, based on high-precision relocated aftershock data from the Turkish double earthquakes and multi-source geological and geophysical data, precisely constructed the three-dimensional geometric structure of the Malatya Fault and the fault that generated the earthquakes. On this basis, combined with geodetic data constraints, a three-dimensional viscoelastic finite element model of the eastern Turkey region was established. This study aims to quantitatively calculate the coseismic and postseismic viscoelastic relaxation effects of the double earthquakes on the Coulomb stress loading characteristics of the Malatya Fault through numerical simulation methods, and analyze the spatiotemporal distribution patterns of stress along the fault strike and at depth. By integrating the fault's own seismogenic background and tectonic loading environment, a comprehensive assessment of the current seismic hazard of the Malatya Fault is conducted, providing a scientific basis for understanding the stress interaction between faults and regional earthquake prevention and disaster reduction.