在Zagros地区 (伊朗) 的地震源参数来自时间进化的P波移位
Sahar Nazeri1, Fatemeh Abdi2, Amir Ismail3
1Department of Physics E. Pancini, University of Naples Federico II, Naples, Italy. sahar.nazeri@unina.it.
Scientific reports
|October 20, 2023
概括
这项研究使用强运动数据分析了扎格罗斯地区地震破裂过程. 结果显示,几乎恒定的应力下降约为1MPa,这表明中等到大地震事件的自我相似缩放.
科学领域:
- 地震学 地震学
- 地震破裂的动态地震破裂的动态
- 地质物理学 地质物理学
背景情况:
- 扎格罗斯地区位于伊朗高原,地震活跃,容易发生中等到大地震.
- 了解地震破裂过程对于地震危险评估和减轻至关重要.
研究的目的:
- 为了研究Zagros地区中等到大地震的破裂过程.
- 为了确定地震源的关键参数,包括时刻大小,破裂持续时间和长度,平均滑动和静态应力下降.
- 分析2017年7.3 Mw的伊朗-伊拉克 (Ezgeleh) 地震作为一个案例研究.
主要方法:
- 来自伊朗建筑和住房研究中心 (BHRC) 的强运动数据分析.
- 使用P波位移信号的时间域参数建模技术的应用.
- 用循环源模型和恒定的破裂速度模拟三角形矩速函数.
- 使用频率-Q参数 (50-200) 和后处理程序模拟无弹性衰减.
主要成果:
- 平均静态应力下降值在0.9 MPa至1.6 MPa之间.
- 地震破裂半径/长度经验上与地震时刻相变,呈现出类似的,几乎恒定的约1MPa的应力下降.
- 对于Ezgeleh地震,估计的参数包括6.9级的瞬间,7秒的破裂时间,16公里的源半径,平均滑动2米,和3.4MPa的静态应力下降.
结论:
- 这项研究证实了萨格罗斯地区破裂大小和地震时刻之间的自我相似的缩放关系.
- 这些发现为在这个构造活跃地区发生的大型地震的来源特征提供了宝贵的见解.
- 该分析强调了在地震源参数估计中考虑无弹性衰减的重要性.
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