Time-domain acceleration-based pulse characterization of 2023 Kahramanmaraş earthquakes

On February 6, 2023, two significant earthquakes struck the region of Kahramanmaraş, Türkiye. The first earthquake, with a magnitude of 7.7 and a depth of 8.6 km, occurred in Pazarcık, and the second earthquake, with a magnitude 7.6 and a depth of 7.0 km, struck Elbistan. These two devastating events led to the loss of lives and massive destruction of civil infrastructures. In this work, pulse components of the ground motions for both earthquakes are characterized through a multi-pulse decomposition method developed by the authors. The work particularly focuses on cumulative energy, period, and amplitude of dominant pulse components using two extensive ground motion ensembles: (1) 103 ground motions from the Pazarcık earthquake, and (2) 79 ground motions from the Elbistan earthquake. It is found that, for the Pazarcık earthquake, pulse cumulative energy is more pronounced for the ground motions in proximity to the rupture lines. However, for the Elbistan earthquake, pulse cumulative energy is not significant for the ground motions in a specific area and is roughly uniformly distributed across all the ground motions and the entire region. It is also seen that dominant pulse periods lie predominantly within the range of 0.5–1.5 s for both earthquakes highlighting the significant damage caused. Finally, the pulse amplitudes exceed 0.5 g for several ground motions of the Pazarcık earthquake while all the amplitudes fall below 0.5 g for the Elbistan earthquake.