南堡凹陷地壳构造稳定性:源自地震活动时空特征的证据  

Tectonic stability of the Nanpu sag:Evidence from temporal and spatial characteristics of seismic activity

作　　者：张扬 商琳[1] 王淼[1] 吴海涛[1] 段彬[1] ZHANG Yang;SHANG Lin;WANG Miao;WU Haitao;DUAN Bin(PetroChina Jidong Oilfield Company,Tangshan 063000,Hebei,China)

机构地区：[1]中国石油冀东油田分公司,河北唐山063000

出　　处：《地质力学学报》2025年第2期313-324,共12页Journal of Geomechanics

基　　金：地球深部探测与矿产资源勘查国家科技重大专项(2024ZD1000701)。

摘　　要：区域构造稳定性评价在重大工程的规划和建设中发挥着重要的参考作用。目前南堡凹陷作为中国海上储气库的建设地,其构造稳定性成为关注的热点。基于区域历史地震数据,总结了南堡凹陷及周边地震活动的时空分布规律,分析了唐山-河间-磁县断裂带和张家口-蓬莱断裂带的破裂模式,探讨了南堡凹陷地壳的构造稳定性。研究结果表明,南堡凹陷是活动构造带附近相对稳定的“安全岛”。区域上,南堡凹陷周缘积累的应力主要通过滦县-乐亭和宝坻-宁河等断裂带活动得以释放,周缘的地震活动对南堡凹陷内部的影响十分有限;而在南堡凹陷的内部,发育一个以蠕滑为主的大型伸展变形系统。根据现今的构造应力背景,南堡凹陷内的应力仅需要积累很小的量级就会诱发先存正断层的不稳定滑动,这意味着应力无法长期积累。因此,南堡凹陷内部不具备发生大地震的条件。[Objective]The evaluation of regional tectonic stability plays a crucial role in the planning and construction of major projects.Given that the Nanpu sag is the site for China's first offshore gas storage facility,its tectonic stability is naturally a focal point of concern.[Methods]Based on historical seismic data for the region,this study summarizes the spatiotemporal distribution of seismic activities in the Nanpu sag and its surrounding areas.It analyzes the rupture modes of the Tangshan-Hejian-Cixian fault zone and the Zhangjiakou-Penglai fault zone,and explores the tectonic stability of the Nanpu sag.[Results]The results indicate that the Nanpu sag is a relatively stable"safe island"near active tectonic zones.Regionally,stress accumulated around the periphery of the Nanpu sag is mainly released through the activity of faults such as the Luanxian-Laoting and Baodi-Ninghe faults,and the influence of the seismic activity at the periphery on the interior of the Nanpu sag is limited.Internally,a large-scale creep-dominated extensional deformation system has developed within the Nanpu sag.[Conclusion]Given the current tectonic stress background,only a small magnitude of stress accumulation is required to trigger unstable sliding of pre-existing normal faults within the Nanpu sag.This suggests that stress cannot accumulate over long time scales,and thus the interior of the Nanpu sag lacks conditions for the occurrence of major earthquakes.

关 键 词：断裂带破裂模式 地震活动 地壳构造稳定性 南堡凹陷 构造应力 

分 类 号：P54[天文地球—构造地质学] P315.2[天文地球—地质学]