美国南加州大学Binhao Wang和Sylvain Barbot合作的一项最新研究，揭示了东安纳托利亚断层(土耳其)断裂分段，受结构复杂的断层系统长期滑动速率沿走向变化的控制。该研究于2024年7月24日发表于国际一流学术期刊《地质学》杂志上。

研究人员使用地震周期的数值模型探索了连续的单段和多段破裂的力学机制，该地震周期根据历史地震记录和2023年双重地震的大地测量观测进行了校准。研究模型成功地再现了观测到的历史分段断裂和罕见的多段地震。这种分段模式受阿拉伯板块和安纳托利亚板块之间，运动复杂的断层网络沿走向的长期滑动速率变化的影响。基于物理学的地震周期模拟，研究结果揭示了形成地震灾害的地震规模的长期变化。

据研究人员介绍，土耳其的东安纳托利亚断层表现出沿走向分段断裂，通常引发矩震级(Mw)高达7.5的地震，且局限于单个分段。然而，在2023年2月6日，Kahramanmara附近(土耳其东南部)发生了灾难性的7.8级地震，通过跨越多于300km的多个分段，打破了之前的预期并克服了多种几何复杂性。

附：英文原文

Title: Rupture segmentation on the East Anatolian fault (Turkey) controlled by along-strike variations in long-term slip rates in a structurally complex fault system

Author: Binhao Wang, Sylvain Barbot

Issue&Volume: 2024-07-24

Abstract: The East Anatolian fault in Turkey exhibits along-strike rupture segmentation, typically resulting in earthquakes with moment magnitude (Mw) up to 7.5 that are confined to individual segments. However, on 6 February 2023, a catastrophic Mw 7.8 earthquake struck near Kahramanmara (southeastern Turkey), defying previous expectations by rupturing multiple segments spanning over 300 km and overcoming multiple geometric complexities. We explore the mechanics of successive single- and multi-segment ruptures using numerical models of the seismic cycle calibrated to historical earthquake records and geodetic observations of the 2023 doublet. Our model successfully reproduces the observed historical rupture segmentation and the rare occurrence of multi-segment earthquakes. The segmentation pattern is influenced by variations in long-term slip rate along strike across the kinematically complex fault network between the Arabian and Anatolian plates. Our physics-based seismic cycle simulations shed light on the long-term variability of earthquake size that shapes seismic hazards.

DOI: 10.1130/G52403.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G52403.1/645839/Rupture-segmentation-on-the-East-Anatolian-fault