EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Direct Rupture Speed Estimation from "Rupture Phase" of the 2023 Turkey Mw 7.8 Earthquake

Suli Yao and Hongfeng Yang
Suli Yao and Hongfeng Yang
  • Earth and Environmental Sciences Programme, Chinese University of Hong Kong, Hong Kong, China

Rupture speed is a fundamental dynamic characteristic of earthquakes, which can be inferred by multiple approaches such as the back projection (BP) and kinematic fault slip inversion with near-field or far-field data as constraints. Here we propose a rapid estimate for rupture speed directly from the strong motion records along the southern segment of the Mw 7.8 Turkey earthquake on 6 Jan 2023. We collect data on 12 strong motion stations that are located within 3 km from the major fault trace. Due to the short distances to the fault, the ground motions on these stations can approximate a very local rupture phase, with the peak amplitudes of fault-parallel velocities corresponding to the rupture front passage. We pick peak velocities on three components and obtain an apparent propagation speed of ~ 3 km/s. To validate the correlation between the rupture speed and the apparent rupture-phase speed, we conduct 3-D dynamic rupture simulations for this Mw 7.8 event and compare the synthetic rupture front with the rupture phase. We find that the rupture speed is slightly higher than the rupture-phase speed with a difference of 5% - 10%. Based on our modeling results, we infer the actual rupture speed of ~3.2 km/s along the south segment in the Mw 7.8 Turkey earthquake. Different from those waveform-fitting methods that require certain assumptions on the earthquake source, such as the relation between the rupture front and the radiation process or the slip rate function, our approach provide a fast and robust rupture speed estimation that can be done in real time.

How to cite: Yao, S. and Yang, H.: Direct Rupture Speed Estimation from "Rupture Phase" of the 2023 Turkey Mw 7.8 Earthquake, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-17632,, 2023.