大地测量与地球动力学2025，Vol.45Issue(8)：834-839,6.DOI:10.14075/j.jgg.2024.09.428
利用深反射剖面初至波走时反演唐山市北部浅层速度结构
Inversion of Shallow Velocity Structure in Northern Tangshan Using First Arrival Traveltime from Deep Reflection Profile
摘要
Abstract
The first arrival travel times of a deep reflection profile,approximately 30 km long,imple-mented along the northwest-southeast direction across the northern segment of the Tangshan fault in 2023 were inverted to obtain a detailed shallow velocity structure profile in the northern part of Tangs-han.The velocity structure profile reveals that from 2.5 to 8.5 km along the survey line,the Cenozoic Era sediments are about 150 m thick and relatively uniform.The Fengtai-Yejituo fault is hidden at the survey line coordinate of 3.5 km,trending northwest,and F2-1 fault is hidden at 8.5 km,trending southeast;there is a hidden bulge between these two faults that is low in the northwest and high in the southeast.From 8.5 to 15.2 km along the survey line,the Cenozoic Era sediments gradually thicken from northwest to southeast,with a maximum thickness of about 250 m,indicating that the Jinggezhuang depression is a gull-shaped Cenozoic fault depression.The Douhe fault is exposed at 15.2 km,trending northwest.From 15.2 to 24 km along the survey line,it is the Tangshan uplift,with only local areas having very thin Cenozoic Era sediments,and the P-wave velocity at the same depth is much higher than on both sides;there is a nearly vertical low-velocity zone under Weishan,extending at least 600 m downward,which is speculated to be the fault zone of the Tangshan-Weis-han-Changshan south slope fault belt.From the survey line coordinate of 24 km to the end of the sur-vey line,it is the northwestern part of the Kaiping depression,showing a regular basin edge morphol-ogy,with Cenozoic Era sediments of about 130 m.The Douhe fault and the Tangshan-Weishan-Chan-gshan fault are active faults of the Quaternary.关键词
唐山市北部/初至波走时成像/浅部速度结构/断裂活动性/地质构造Key words
northern Tangshan/first arrival travel time tomography/shallow velocity structure/fault activity/geological structure分类
天文与地球科学引用本文复制引用
贾佳,王夫运,刘巧霞,段永红,范振宇,王宏伟,高占永..利用深反射剖面初至波走时反演唐山市北部浅层速度结构[J].大地测量与地球动力学,2025,45(8):834-839,6.基金项目
国家自然科学基金(42074070,42374073) （42074070,42374073）
中国地震局地球物理勘探中心青年基金(YFGEC2022005) （YFGEC2022005）
国家重点研发计划(2017YFC1500202). National Natural Science Foundation of China,No.42074070,42374073 （2017YFC1500202）
Youth Fund of Geophysical Exploration Center,CEA,YFGEC2022005 （）
National Key Research and Development Program of China,No.2017YFC1500202. （）
