Pulse-like ground motion observed during the 6 February 2023 MW7.8 Pazarc?k Earthquake (Kahramanmara?, SE Türkiye) |
| |
| Authors: | Fan Wu Junju Xie Zhao An Chenghao Lyu Tuncay Taymaz Tahir Serkan Irmak Xiaojun Li Zengping Wen Baofeng Zhou |
| |
| Affiliation: | 1. Institute of Geophysics, China Earthquake Administration, Beijing 100081, China;2. School of Earth and Space Sciences, Peking University, Beijing 100871, China;3. Department of Geophysical Engineering, The Faculty of Mines, ?stanbul Technical University, Maslak 34467, Sar?yer, ?stanbul, Türkiye;4. Department of Geophysical Engineering, Kocaeli University, Umuttepe 41380, Kocaeli, Türkiye;5. College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, China;6. Institute of Engineering Mechanics, China Earthquake Administration, Harbin 150080, China |
| |
| Abstract: | In this study, we analyzed 100 three-component strong ground motion records observed within 200 km of the causative fault of the 6 February 2023 MW7.8 Pazarc?k (Kahramanmara?) Earthquake in SE Türkiye. The wavelet method was utilized to identify and analyze the characteristics of pulse-like ground motions in the near-fault region, while considering the uncertainty of the pulse orientation during the analysis. Our investigation focused on the effects of the focal mechanism and rupture process on the spatial distribution, pulse orientation, and maximum pulse direction of the observed pulse-like ground motion. We also analyzed the amplitude and period of the observed ground pulses and the effect of long-period amplification on the ground motion response spectra. Our results indicated the following: (1) A total of 21 typical ground velocity pulses were observed during this earthquake, exhibiting complex characteristics due to the influence of the strike-slip mechanism and rupture directivity. Most ground pulses (17 out of 21) were recorded within 20 km of the fault, in a wide range of orientations, including normal and parallel to the fault direction. The waveforms exhibited unidirectional features, indicating the effects of left-lateral fault slip. Distinct pulses observed more than 20 km from the fault were mainly oriented normal to the fault. The waveforms were bidirectional with double- or multi-round trips as a result of rupture directivity. (2) The amplitudes of the observed pulses ranged from 30.5 to 220.0 cm/s, with the largest peak velocity of 220.0 cm/s observed at Station 3138. The pulse periods ranged from 2.3 to 14.5 s, with the longest pulse period of 14.5 s observed at Station 3116. The amplitude and period of the pulses observed during this earthquake were comparable to those of similar-magnitude global earthquakes. The amplitude of the pulses decreased significantly with increasing fault distance, whereas the pulse period was not significantly affected by the fault distance. (3) Compared with non-pulse records, the velocity pulse records had a pronounced amplification effect on the acceleration response spectra near the pulse period, with factors ranging from 2.1 to 5.8. The larger velocity pulses also significantly amplified the velocity response spectra, particularly over the long periods. This significant amplification effect of the pulses on the response spectra leads to empirical models underestimating the long-period earthquake ground motion. |
| |
| Keywords: | pulse-like ground motion response spectrum predominant period |
| 本文献已被 ScienceDirect 等数据库收录！ |
| 点击此处可从《Earthquake Science》浏览原始摘要信息 |
|
点击此处可从《Earthquake Science》下载全文 |
|
