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中国科学院地质与地球物理研究所第十届(2.10年度)学术年会

作者： Ling Chen~* seismological Laboratory(SKL-LE),institute of Geology and{2.,Chinese Academy of Sciences,beijing 10002.,China

This study presents an integrated study of the North China Craton(NCC)based on recent high-resolution seismic images combined with observations on surface geology,regional tectonics and mantle dynamics. Seismic images reveal markedly concordant and rapid variations in crustal and lithospheric structure and thickness,upper mantle anisotropy,and discontinuity structures and thickness of the mantle transition zone near the boundary between the eastern and central parts of the *** rapid variations roughly coincide with the sudden change in both surface topography and gravity field as marked by the North-South Gravity Lineament(NSGL).Such a shallow-deep structural concordance may reflect different lithospheric tectonics and mantle processes in the two domains during the Phanerozoic reactivation of the *** structural variations are particularly present to the west of the NSGL,especially between the Archean Ordos Plateau, which retains the characteristics of a typical craton,and the surrounding Cenozoic rift systems which are underlain by a significantly modified and thinned *** observations provide deep structural evidence that the Phanerozoic reactivation was not confined to the eastern NCC as previously thought,but also affected areas in the central and western NCC,though to a much lesser *** both sides of the NSGL, lithospheric modification and thinning appear to be more pronounced along Paleoproterozoic belts suturing Archean blocks,demonstrating the importance of pre-existing lithosphere-scale structures in controlling the tectonic evolution of the *** further indicates that craton reactivation probably is common given the fact that structural heterogeneities are always present in cratonic *** seismic structural images together with geological,petrological,geochemical and mineral physics data suggest that the fundamental destruction of the eastern NCC lithosphere may have been triggered largely by the deep subduction of t

关键词： North China Craton Lithospheric reactivation Concordant structural variation Pre-existing structure Pacific subduction

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seismological EVIDENCES FOR THE MULTIPLE INCOMPLETE CRUSTAL SUBDUCTIONS IN HIMALAYA AND SOUTHERN TIBET

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地学前缘 2000年第S1期7卷 338-338页

作者： Zeng Rongsheng, Ding Zhifeng, Wu Qingju, Wu Jianping (institute of geophysics, China{2. bureau, beijing 100081, China)

Geological evidences have indicated large\|scale crustal shortening by thrust faultings in Himalaya , such as MCT and MBT. The thrust faulting near Yarlungzampbo suture was also observed. However, it is still unknown to what depth those thrust faultings have been going down into the crust or upper mantle . seismological evidences indicate that the thrust faultings in Himalaya and southern Tibet have extended to a depth of 80 to 100km , and stopped there. The thrust faultings underneath MCT MBT and Yarlungzampbo suture are closely related to the multiple crustal subductions in Himalaya and southern Tibet. It provides important constraints for the collision process between India and Eurasia. The incomplete crustal subductions in this region suggest that the impinging Indian crust is too light to prevent it going further down, and retreat of crustal subduction is required for the continuing northward movement of the Indian plate. The multiple crustal subductions are compatible to the multiple episodes of the geological activities in Himalaya and southern Tibet. At first, the crustal subduction was produced at Yarlungzampbo suture , and stopped at a depth of 80～100km. Then, it migrated to the south, other new crustal subductions would start successively at MCT and MBT respectively. They stopped at a depth of 80 to 100km also. Beside the north\|dipping seismic zones in Himalaya and Yarlungzamp bo suture, another gentle south\|dipping seismic zone,extending from Tangula Shan at the surface to the Moho at Yarlungzampbo suture was also observed. It can be interpreted to be an obduction at Tangula Shan. The multiple incomplete crustal subductions in Himalaya and Yarlungzampbo suture highly imply that the impinging Indian crust has been splitted apart from its upper\|most mantle, which may b e subducted deeper into the Eurasian mantle.

关键词： Himalaya Tibetan plateau continent\|continent collision

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基于单台加速度记录的混合全局优化HVSR反演场地浅层速度结构

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地球物理学报 2018年第3期61卷 938-947页

作者：荣棉水符力耘李小军中国地震局地壳应力研究所北京100085 中国科学院地质与地球物理研究所北京100029 中国地震局地球物理研究所北京100081

利用水平与竖向谱比(HVSR)方法反演场地速度结构是国际上迅速发展的研究领域.HVSR反演计算实质是一个土层场地模型空间搜索的全局优化问题,当模型搜索空间的复杂程度增大时,目前常用的搜索算法收敛速度慢,计算效率较低.本文实现了一种... 详细信息

利用水平与竖向谱比(HVSR)方法反演场地速度结构是国际上迅速发展的研究领域.HVSR反演计算实质是一个土层场地模型空间搜索的全局优化问题,当模型搜索空间的复杂程度增大时,目前常用的搜索算法收敛速度慢,计算效率较低.本文实现了一种结合遗传和模拟退火方法优点的混合全局优化HVSR反演算法,通过理论模型和竖向台阵实测数据的检验,表明该算法能获得很好的反演效果,较好地解决了蒙特卡罗方法收敛速度慢,遗传算法收敛早熟和模拟退火算法搜索效率低的问题.本文在此基础上讨论了单台加速度S波记录用于场地速度结构HVSR反演的适用性,为基于单个地震台的地震观测记录反演浅层速度结构提供了一种高效且较为准确的反演方法.

关键词：水平与竖向谱比(HVSR) 遗传算法模拟退火算法混合全局优化算法浅层速度结构反演

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Variation of Electromagnetic Tornogram Before and After Earthquakes

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Earthquake Research in China 1998年第2期12卷 70-76页

作者： Sun Cichang,Wang Xusheng,Liu Qingfang,Tao Yulu,Yu Ping,and Feng Ruiinstitute of geophysics,SSB,{2. 100081,China Department of geophysics,Peking University,{2. 100871,China Seismnlogical bureau of Hunan Province,Changsha 410001,China Center for seismological Data and Information,SSB,{2. 100045,China

Cross-well electromagnetic tomography has been used to monitor the changes of the abso rption coefficient of electromagnetic waves before and after earthquakes for 5 years at Dahuichang fault since *** has been found that 3 months before the occurrence of moderately strong earthquakes(ML≥4.0,△2.0 km),several special changes in tomogram appeared as follows:The mean-value of the absorption coefficient dropped about 10% compared with the annually decreasing tendency; the mean difference of pixels suddenly decreased or increased in different directions; and the entropy of the paragenic matrix in a tomogram decreased and the number of low absorption pixels *** is inferred that such changes in electromagnetic tomograms are attributed to the variation of micro-cracks and porosity in *** tomography can be studied as a new technique to detect earthquake precursors.

关键词： Electromagnetic tomogram Dahuichang fault Earthquake precursor Imageanalysis.

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A two-dimensional hybrid method for modeling seismic wave propagation in anisotropic media

A two-dimensional hybrid method for modeling seismic wave pr...

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中国科学院地质与地球物理研究所2.08学术年会

作者： Liang Zhao,Lianxing Wen,Ling Chen,and Tianyu Zheng 1 seismological Laboratory,institute of Geology and{2., Chinese Academy of Sciences,beijing,China. 2.Department of Geosciences,State University of New York at Stony Brook,Stony Brook,New York,USA.

[1]A hybrid method is developed for calculating synthetic seismograms for seismic waves propagating in two-dimensional localized heterogeneous anisotropic media. The hybrid method is a combination of analytic and numerical methods,with the numerical method(finite difference,or FD) applied in the heterogeneous anisotropic region only and the analytic method(generalized ray theory,or GRT) *** GRT solutions from a seismic source are interfaced with the FD calculation at the boundaries of the anisotropic region;and seismic responses at the Earth’s surface are obtained from the output of FD *** experiments on both isotropic and anisotropic models demonstrate the validity of the new method in simulating seismic wave propagation in complex *** applied the hybrid method to study the SKS wave propagation in the upper *** calculated the synthetics for a series of laterally varying anisotropic models,including a layer with varying anisotropy,two-layer anisotropy,separated anisotropic body and those may be related to subduction *** these laterally varying models,SKS waveforms exhibit higher sensitivity to the spatial variation of anisotropy than the shear wave splitting parameters *** results of this study demonstrate the potential of the proposed hybrid method for high-resolution imaging the laterally varying anisotropic structures from seismological observations, when the tectonic structures can be approximated as two-dimensional.

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Features of Seismic Waves Observed by Downhole Seismometers

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Earthquake Research in China 1994年第1期8卷 108-123页

作者： Zhang Shaoquan,Yang Maoyuan,Guo Jianmin,Zhu Yuanqing,Lin Yunsong,Wang Junguo,Wei Pengfei and Wei Shizhonginstitute of geophysics,SSB,{2. 100081,China seismological Press,SSB,{2. 100081,China Graduate School,Academia Sinica,{2. 100039,China seismological bureau of Tianjin,Tianjin 3002.1,China

In this paper,the authors have summarized the kinematic and dynamic features of seismic waves observed by downhole seismometers in *** features of seismic waves recorded on ground and downhole as well as in soil layer and bedrock layer,including amplitude,traveltime,spectrum and wave field are discussed individually and then explained integrally in term of the effects of soft covering *** research result has been applied to the establishment of downhole seismic stations,the location of fractures in oil fields and the measurement of seismic focus parameters and structural parameters of media.

关键词： records covering summarized borehole laver basement explained strata depths magnitude

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Active extension of the Shanxi rift,north China:does it result from anticlockwise block rotations?

Active extension of the Shanxi rift,north China:does it resu...

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中国科学院地质与地球物理研究所2.04学术年会

作者： Jiankun He,~1 Dongsheng Cai,~2.Yanxing Li~3 and Zaisheng Gong~2.1 institute of Geology and geophysics,Chinese Academy of Sciences,{2. 10002.,China.2.Research Center of China National Offshore Oil Company.{2..10002.,China.3 First Crustal Deformation Monitoring Center.China Scismological Burcan.Tianjin,300180.China

The Shanxi rift is an intraplate extensional zone in the North China *** extension has previously been considered to result from anticlockwise block rotation,with successive indentation of the Indian plate toward the Eurasian ***,GPS data show that the entire North China Block is moving coherently from WNW to ESE,indicating that no significant block rotations presently exist along the two sides of the *** use a viscoelastic model to predict that its active extension might be caused by intraplate deformation localization with lateral changes of the crustal rheological structures.A model result shows that for the ESE movement of the North China Block,the existing topographical loading and crustal weakness could have resulted in the obvious long-term extension of the Shanxi rift even without different block *** surface extension rate approximated from lateral inhomogeneous crustal models is～0.5- 1,4 mm yr,consistent with observed geological and seismological extension rates.

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Structure of the crust and uppermost mantle of the Yanshan Belt and adjacent regions at the northeastern boundary of the North China Craton from Rayleigh Wave Dispersion Analysis

Structure of the crust and uppermost mantle of the Yanshan B...

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中国科学院地质与地球物理研究所2.08学术年会

作者： Qunshu Tang~*,Ling Chen~1 seismological Laboratory(SKL-LE),institute of Geology and{2.,Chinese Academy of Sciences,beijing 10002.,China

We have used Rayleigh wave dispersion analysis and inversion to produce a high resolution S-wave velocity imaging profile of the crust and uppermost mantle structure beneath the northeastern boundary regions of the North China Craton(NCC).Using waveform data from 45 broadband NCISP stations,Rayleigh wave phase velocities were measured at periods from 10 to 48 s and utilized in subsequent inversions to solve for the S-wave velocity structure from 15 km down to 12. km *** inverted lower crust and uppermost mantle velocities, about 3.75 km/s and4.3 km/s on average,are low compared with the global *** Moho was constrained in the depth range of 30-40 km,indicating a typical crustal thickness along the ***,a thin lithosphere of no more than 100 km was imaged under a large part of the profile,decreasing to only - 60 km under the Inner Mongolian Axis(IMA) where an abnormally slow anomaly was observed below 60 km *** overall structural features of the study region resemble those of typical continental rift zones and are probably associated with the lithospheric reactivation and tectonic extension widespread in the eastern NCC during Mesozoic-Cenozoic *** high velocities,up to～4.6 km/s,were found immediately to the south of the IMA beneath the northern Yanshan Belt(YSB),extending down to>100-km *** anomalous velocities are interpreted as the cratonic lithospheric lid of the region,which may have not been affected by the Mesozoic-Cenozoic deformation process as strongly as other regions in the eastern *** on our S-wave velocity structural image and other geophysical observations,we propose a possible lithosphere-asthenosphere interaction scenario at the northeastern boundary of the *** speculate that significant undulations of the base of the lithosphere, which might have resulted from the uneven Mesozoic-Cenozoic lithospheric thinning,may induce mantle flows concentrating beneath the weak IMA *** relatively thick

关键词： Rayleigh waves North China Craton Yanshan belt Crustal and uppermost mantle structure Lithospheric reactivation

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ON THE GANSU-QINGHAI-SICHUAN SEISMO-GENETIC BLOCK AND THE CHARACTERISTICS OF ITS EARTHQUAKE ACTIVITIES

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Chinese Science Bulletin 1983年第10期28卷 1381-1387页

作者：阎志德郭履灿 institute of geophysics State Seismological Bureau. Beijing institute of geophysics State Seismological Bureau. Beijing? INTRODUCTION In the recent 20 years research on plate tectonics has shown that large earthquakes are closely related with plate boundaries revealing some regularities of earthquake occurrences particularly in oceanic and continental boundary regions. On further researchesmore miniplates have been divided by some investigators such as for some intraconti-

Ⅰ. INTRODUCTION In the recent 2. years, research on plate tectonics has shown that large earthquakes are closely related with plate boundaries, revealing some regularities of earthquake occurrences, particularly in oceanic and continental boundary regions. On further researches,more miniplates have been divided by some investigators, such as for some intraconti-

关键词： continental tectonics southeast oceanic revealing northwest marginal migrate alternate northeast

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榆神府矿区大柳塔井田煤层群采地面沉陷可视化数值模拟

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水文地质工程地质 2003年第6期30卷 37-39,115页

作者：武强王龙魏学勇傅耀军沈智慧中国矿业大学煤炭资源教育部重点实验室北京100083 国家地震局地壳应力研究所北京100085 中国煤炭地质局水文地质局邯郸056004

针对晋陕蒙能源基地榆神府矿区大柳塔井田的地面沉陷问题,在分析研究区内水文地质、工程地质条件的基础上,确立了研究区的评价模型并采用世界上先进的数值模拟评价的FLAC3D专业软件包,对该矿区煤层群采的地面沉陷情况进行了可视化数值... 详细信息

针对晋陕蒙能源基地榆神府矿区大柳塔井田的地面沉陷问题,在分析研究区内水文地质、工程地质条件的基础上,确立了研究区的评价模型并采用世界上先进的数值模拟评价的FLAC3D专业软件包,对该矿区煤层群采的地面沉陷情况进行了可视化数值仿真模拟分析。

关键词：工程地质条件地面沉陷三维可视化数值模拟

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