近日，新加坡南洋理工大学Tong, Ping团队报道了2023年卡赫拉曼马拉什7.8级地震期间，高正应力促进了超剪切破裂。这一研究成果发表在2026年1月6日出版的《自然—地球科学》杂志上。
2023年2月6日，两次矩震级（Mw）分别为7.8和7.6的大地震破坏了东安纳托利亚断层系统的多个断层段，在土耳其和叙利亚造成了大量人员伤亡和广泛的财产损失。7.8级地震涉及东安纳托利亚断层沿线的双向破裂，其中至少部分向东北方向为超剪切破裂，向西南方向为次剪切破裂。造成这种破裂速度差异的原因仍有争议。
研究组通过地震层析成像技术提供的证据，将这种差异与断层沿线的结构和应力变化联系起来。具体而言，西南部的阿马诺斯-帕扎尔奇克断层段存在低速异常和与断层平行的快速速度方向各向异性，这表明存在流体渗透，可能促进断层蠕变并降低应力加载速率。相比之下，东北部的埃尔克内克断层段则与高速异常和与断层垂直的快速速度方向相关，这表明流体渗透有限且应力积累增加。因此，研究组认为应力积累的差异解释了此次地震中破裂速度的差异，并且除应力加载外，断层结构也可能影响应力积累，进而影响断层是否以超剪切速度破裂。
附：英文原文
Title: High normal stress promoted supershear rupture during the 2023 Mw 7.8 Kahramanmara earthquake
Author: Chen, Jing, Xu, Mijian, Bai, Yiming, Wu, Shucheng, Xiao, Xiao, Hao, Shijie, Nagaso, Masaru, Yang, Hongfeng, Tong, Ping
Issue&Volume: 2026-01-06
Abstract: On 6 February 2023, two major earthquakes with moment magnitude (Mw) of 7.8 and 7.6 ruptured multiple segments of the Eastern Anatolian Fault system, resulting in many casualties and extensive property damage in Turkey and Syria. The Mw 7.8 earthquake involved bilateral rupture along the Eastern Anatolian Fault, with at least partially supershear rupture towards the northeast and subshear rupture towards the southwest. The cause of this difference in rupture speed remains debated. Here we present evidence from seismic tomographic imaging linking this difference to structural and stress variations along the fault. Specifically, a low-velocity anomaly and a fault-parallel fast velocity direction of anisotropy in the southwest Amanos–Pazarck segment suggest fluid infiltration, which could facilitate fault creep and reduce the stress loading rate. By contrast, the Erkenek segment to the northeast is associated with a high-velocity anomaly and fault-normal fast velocity direction, suggesting limited fluid infiltration and increased stress accumulation. Hence, we propose that the contrast in stress accumulation explains the discrepancy in rupture speeds in this earthquake and that fault structure in addition to stress loading may influence stress accumulation and thus whether a fault ruptures at supershear speeds.
DOI: 10.1038/s41561-025-01893-z
Source: https://www.nature.com/articles/s41561-025-01893-z