Rupture Process and Ground Motion Complexity of the February 6, 2023, Mw 7.8 Kahramanmaraş Earthquake in Türkiye: Insights from Analysis of Deterministic Broad-band Simulations using a Regional 1D Velocity Model
Description:
On February 6, 2023, two of Türkiye's most destructive earthquakes struck the Kahramanmaraş region, causing severe casualties and widespread destruction across south-central Türkiye and northwestern Syria. The first event, an Mw 7.8 earthquake, occurred circa 20 km east of the main strand of the East Anatolian Fault Zone (EAFZ), followed nine hours later by an Mw 7.6 earthquake near the Sürgü-Cardak Fault Zone. These two earthquakes, separated by 90 km and exhibiting comparable magnitudes, generated exceptionally high ground motions, with peak ground accelerations exceeding 1000 cm/s² and peak ground velocities surpassing 100 cm/s. The extreme motions, particularly pronounced in Hatay Province near the Amik Basin, caused catastrophic structural failures, including the collapse of modern reinforced concrete buildings. These collapses demonstrated uprooting mechanisms, underscoring the inadequacy of current seismic design codes to address large impulsive near-fault ground motions. The complex rupture processes, characterized by varying velocities, geometries, and time delays across branched fault segments, offer unique insights into rupture dynamics and seismic hazard in the region.
This study examines the rupture process of the Mw 7.8 mainshock using kinematic rupture modeling with the Graves and Pitarka (2016) hybrid-source method and the frequency-wavenumber approach. Simulations, validated against strong-motion data from over 50 stations within 50 km of the fault, capture near-fault ground motions in the 0–3 Hz frequency range and incorporate multi-scale heterogeneity with high-slip patches and stochastic variations. Sensitivity analyses evaluate the effects of key kinematic parameters, such as rupture velocity, rise time, and slip distribution, on ground motion amplification. These findings enhance understanding of rupture dynamics and provide valuable insights for seismic hazard mitigation in tectonically active regions. This framework applies to similar earthquake scenarios worldwide, such as those along the Hayward and Calaveras faults in California.
Session: Recent Advances in Modeling Near-source Ground Motions for Seismic Hazard Applications [Poster]
Type: Poster
Date: 4/16/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Aybige
Student Presenter: No
Invited Presentation:
Poster Number: 50
Authors
Aybige Akinci Presenting Author Corresponding Author aybige.akinci@ingv.it National Institute of Geophysics and Volcanology |
Arben Pitarka pitarka1@llnl.gov Lawrence Livermore National Laboratory |
Pietro Artale Harris pietro.artale@ingv.it National Institute of Geophysics and Volcanology |
Kenichi Tsuda kenichi.tsuda@shimz.co.jp Shimizu Corporation |
Robert Graves rwgraves@usgs.gov U.S. Geological Survey |
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Rupture Process and Ground Motion Complexity of the February 6, 2023, Mw 7.8 Kahramanmaraş Earthquake in Türkiye: Insights from Analysis of Deterministic Broad-band Simulations using a Regional 1D Velocity Model
Category
Recent Advances in Modeling Near-source Ground Motions for Seismic Hazard Applications