Nazeri Sahar, Abdi Fatemeh, Ismail Amir, Rahimi Habib, Zollo Aldo
Department of Physics E. Pancini, University of Naples Federico II, Naples, Italy.
Institute of Geophysics, University of Tehran, Tehran, Iran.
Sci Rep. 2023 Oct 20;13(1):17964. doi: 10.1038/s41598-023-45119-x.
The rupture process of the recent moderate-to-large earthquakes in the Zagros area along the Iran plateau is investigated by analysing the strong motion data provided by the Iranian Building and Housing Research Centre (BHRC). The selected dataset includes the largest and deadliest 2017 Mw 7.3, Iran-Iraq (Ezgeleh) earthquake. The earthquake source parameters (moment magnitude, rupture duration and length, average slip, and static stress drop) are determined using a time-domain, parametric modelling technique based on the time evolution of the P-wave displacement signals. The earthquake source parameters are calculated from simulated triangular moment-rate functions assuming the circular source models for a constant rupture velocity. The anelastic attenuation effect is modelled through the independent frequency-Q parameter ranging from 50 to 200 and accounted for by a post-processing procedure that retrieves the attenuation-corrected, moment-rate triangular shape. Results show that the average static stress-drop with different [Formula: see text], varies between <Δσ> = 0.9 (0.7-1.2) MPa and <Δσ> = 1.6 (1.2-2.0) MPa. Overall, in this research, the rupture radius/length empirically scales with the seismic moment with a self-similar, near-constant stress drop of about 1 MPa. Assuming a circular rupture model for the Ezgeleh earthquake, we estimate a moment magnitude of 6.9, rupture duration of 7 s, source radius of 16 km, average slip of about 2 m and static stress drop of 3.4 MPa.
通过分析伊朗建筑与住房研究中心（BHRC）提供的强震数据，对伊朗高原沿扎格罗斯地区近期中到大地震的破裂过程进行了研究。所选数据集包括2017年造成人员伤亡最多的Mw 7.3级伊朗 - 伊拉克（埃兹盖勒）地震。利用基于P波位移信号时间演化的时域参数建模技术，确定了地震源参数（矩震级、破裂持续时间和长度、平均滑动和静态应力降）。地震源参数是根据假设恒定破裂速度的圆形源模型，从模拟的三角形矩速率函数计算得出的。通过独立频率 - Q参数范围从50到200对非弹性衰减效应进行建模，并通过一种后处理程序进行考虑，该程序可恢复经衰减校正的矩速率三角形形状。结果表明，不同[公式：见原文]下的平均静态应力降在<Δσ> = 0.9（0.7 - 1.2）MPa和<Δσ> = 1.6（1.2 - 2.0）MPa之间变化。总体而言，在本研究中，破裂半径/长度与地震矩呈经验性比例关系，具有约1MPa的自相似、近乎恒定的应力降。假设埃兹盖勒地震为圆形破裂模型，我们估计其矩震级为6.9，破裂持续时间为7秒，震源半径为16公里，平均滑动约2米，静态应力降为3.4MPa。
