近日，日本东京工业大学Weerachai Siripunvaraporn团队探明了马尔马拉海下北安纳托利亚断层高变形富流体弱带和锁断段的三维电磁成像。2025年12月8日出版的《地质学》杂志发表了这项成果。

对北安纳托利亚断裂带下方（特别是在马尔马拉海下已保持250年以上地震平静的区域）地壳性质的可靠认知，对理解地震危险性和减轻大规模潜在灾害至关重要。

研究组首次对马尔马拉海地区的大地电磁数据集进行三维反演建模，揭示了沿该剪切变形带存在的局部脆弱及闭锁断层段。在北安纳托利亚断裂带北支下方、中央盆地与恰纳尔哲克-伊姆拉勒盆地沿线出现的低电阻率区域，很可能源于流体的存在——这可能是破碎带中的断裂带导体，并能够解释该区域密集的微震活动。这些被较高电阻率结构包围的低电阻率异常表明，分段式、多分支的北安纳托利亚断裂系统沿着本都缝合带延伸至马尔马拉海下方。而在中央盆地与恰纳尔哲克盆地之间，以及马尔马拉海西端与东端出现的电阻率高异常，很可能标志着应力积累区，从而揭示了这一关键区域内正在进行的断层力学过程。

附：英文原文

Title: 3-D electromagnetic imaging of highly deformed fluid-rich weak zones and locked section of the North Anatolian fault beneath the Marmara Sea

Author: Tulay Kaya-Eken, Yasuo Ogawa, Yoshiya Usui, Takafumi Kasaya, M. Kemal Tuner, Yoshimori Honkura, Naoto Oshiman, Masaki Matsushima, Weerachai Siripunvaraporn

Issue&Volume: 2025-12-08

Abstract: Reliable knowledge of the crustal properties beneath the North Anatolian fault (NAF), seismically silent for more than 250 years beneath the Marmara Sea (MS), is crucial for understanding seismic hazard and mitigating the potential for disaster on an enormous scale. In the present work, the first three-dimensional inverse modeling performed on a magnetotelluric dataset of the MS has unveiled localized weak and locked fault segments along this shear deformation zone. Low-resistivity regions along the northern branch of the NAF beneath the Central and narck-Imral basins are likely attributed to the presence of fluids, which may represent a fault zone conductor in a fractured zone and can explain the densely populated microseismicity. These low-resistivity anomalies surrounded by higher resistivity structures imply that the segmented, multi-branched NAF system extends beneath the MS, following the Intra-Pontide suture zone. The resistive anomalies, between the Central and narck basins, along with those at the western and eastern extremities of the MS, presumably signify regions of stress accumulation, shedding light on the ongoing processes of fault mechanics at play in this critical region.

DOI: 10.1130/G52995.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G52995.1/722052/3-D-electromagnetic-imaging-of-highly-deformed