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在城市活断层勘探中,对于面波干扰大、地震反射波法难以开展工作的区域,可尝试利用地震折射波法进行探测,并对折射波法探测的原始记录采用时间项、差异时距曲线和有限差分成像等方法进行综合计算、分析,以探索折射波法在城市活断层勘探中的应用成效。文中针对郑州市须水断层西段浅层地震折射波法勘探记录,利用时间项、差异时距曲线和有限差分成像等计算方法,获取剖面速度结构与界面构造;综合震相特征、计算结果等资料确定主要地层的界面深度和构造特征,3种方法都取得了相近的结论。后又通过在测线上4个钻孔资料的验证,认为3种方法的计算结果与钻孔资料相吻合,说明折射波法勘探在城市活断层探测中的应用是可行的 相似文献
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通过在上海地区开展深、浅地震反射、地震宽角反射/折射、高分辨地震折射和大地电磁测深等联合剖面探测, 获得了该地区近地表至Moho面的精细速度结构、电性结构和深浅构造关系.结果表明, 该地区地壳可划分为上、中、下三个组成部分.其中，上地壳厚为12～14 km，波速为57～59 km/s；中地壳厚度约为10 km，波速为59～62 km/s；下地壳厚为10～11 km, 波速为62～63 km/s，Moho面深度约为32 km.剖面浅部地质构造复杂，共解释出12条特征明显的断裂.其中，除3条断裂错断结晶基底（G界面）并向下延伸至上地壳底界面外，其他断裂均在深度3～5 km以上终止或收敛于G界面之上.此外，仅在剖面西侧基底下部约13～15 km埋深处发现一厚度在2 km左右的壳内高导层.所以，在综合各方面资料后分析认为，在剖面经过地区不存在发生大地震的深部构造条件，近地表所存在的活动断层是未来产生对该区有影响地震的震源区. 相似文献
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浅层反射地震方法是城市活断层探测常用的技术,但在基岩埋深比较浅的地区,往往只能识别出基岩顶面的反射波,而仅根据反射地震剖面上单个同相轴的变化很难准确判定断层是否存在.浅层地层的错断往往会引起速度的横向变化,利用高分辨折射地震方法采集的数据,应用层析成像方法获得的速度剖面,能够反映地下速度结构的变化,可以从另一方面揭示浅层断层存在的可能性.在四川某地,将这两种方法同时应用于活断层浅层地震勘探中.结果表明,两种方法联合应用可在一定程度上弥补浅层反射地震勘探方法在基岩埋深较浅地区的不足. 相似文献
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利用在北京西北部地区穿过张家口——渤海地震带北西段地震测深剖面进行了综合解释和研究, 揭示了延庆——怀来、 张北——尚义地震活动区异常的深浅地壳结构特征. 结果表明: 研究区基底结构具有明显的起伏变化, 不同的地质构造单元基底埋深存在着较大差异. 基底埋深在局部地段呈现出的急剧变化可视其为基底断裂存在的一种标志, 基底断裂与地壳深断裂的存在为岩浆的上溢提供了条件, 从而导致了地壳结构强烈的非均匀性. 延怀地区壳内复杂反射波组序列和局部强弱不连续反射带现象的出现, 表明该地区地壳结构发生了强烈的挤压变形, 从而构成了该地区复杂的地壳结构, 为该地区地震的发生提供了动力来源; 张北——尚义地区壳内不同深度范围低速异常体和局部的C1界面的存在, 可以认为是岩浆多期活动的产物, 在区域构造活动的作用下脆性的上地壳内, 当局部应力积聚到一定的程度从而引发了地震的发生. 相似文献
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At present, there is less theoretical research and practical experience in the aspect of ultra-shallow seismic exploration to the target layers at depths of only tens of meters both at home and abroad. Seismic exploration plays an important role in the location of faults and active structures, but the depth dozens of meters below the ground surface is the blind area of any kind of deep and shallow seismic exploration. Starting from the point of view of detecting urban active faults, and using related theories and methods of geology, geophysics and mathematics, the paper discusses the preconditions for acquiring efficient ultra-shallow seismic survey results in complicated geological backgrounds in Qingdao. Taking the Qingdao area as an example in this paper, we study the depth condition of Quaternary deposits, and apply 4-8 stacking folds to satisfy the requirement to get the exploration results with high-resolution and high-SNR. Preliminary results reveal that selecting a proper surveillance layout is one of the keys to acquire authentic exploration results in ultra-shallow P-wave reflection exploration. Our results also show that ultra-shallow seismic reflection method in detecting faults in the Qingdao area has good application prospects. 相似文献
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根据邢台7-2 级和6-8 级地震震中区的浅层和超浅层地震勘探结果,查明了震中区浅部铲形断裂的性质及活动年代,认为新河断裂(F1) 自晚更新世以来已不再活动,它不是发震断裂。另外,结合该区深地震反射剖面和深地震测深剖面结果,讨论了震中区的深浅部构造形态及它们的相互关系,从而确定了发震断裂应为震源之下的高倾角超壳断裂①。邢台地震的发生是由于地幔岩浆的上侵作用产生附加应力场,并与区域构造应力场共同作用使该断裂重新活动,引发了邢台地震,并引起浅部断层及地表物质的运动 相似文献
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Introduction Zhangjiakou-Bohai seismic zone is a major active seismic zone that passes through the north-ern part of North China. Zhangjiakou-Beijing area, the northwest part of North China, is located at the intersection position of Yanshan, Taihangshan uplift, and Shanxi down-faulted zone, and the geological structures in this area are extremely complicated. Many researchers in the geoscience circle always pay close attention to this region because Yanqing-Huailai region is located in th… 相似文献
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两个原因使我们必须开展深部探测.一是寻找深部资源,二是更好地理解形成和控制陆内成矿的深部动力学过程,预测新的矿集区.在深部探测专项、国家自然科学基金和地质调查项目资助下,作者在长江中下游成矿带及邻区开展了系统的多尺度、综合地球物理探测.包括:成矿带尺度的宽频地震探测及"廊带式"综合探测,矿集区尺度的骨干剖面探测和三维建模,矿田尺度的三维探测与反演模拟.探测结果在三个层次取得了一系列新认识和新发现,完善了相关探测方法技术.主要包括:揭示了成矿带岩石圈结构、深部过程及对成岩、成矿的控制,提出了成矿带形成的动力学模型,诠释了在狭窄的成矿带内形成大规模金属堆积的深部因素;揭示了典型矿集区地壳三维结构、组成和断裂分布,建立了矿集区三维结构模型和区域成矿模式,推断了主要控矿岩体、地层的空间展布,预测了新的找矿靶区;开展了"玢岩型"、斑岩型和热液型多金属矿床综合地球物理探测试验,总结了勘查模式,预测了深边部找矿靶区;提出了硬岩区反射地震数据采集设计、激发到接收的有效措施,探索了地震弱信号提取、噪声压制、静校正和偏移等处理新技术、新方法;提出了强电磁干扰区电磁去噪的数字形态滤波等技术,完善了二/三维带地形和考虑各向异性情况的电磁正反演技术. 相似文献
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地震属性分析技术在地球物理勘探领域的广泛应用，启发研究人员将其应用于人工源宽角反射/折射深地震测深剖面的资料预处理和震相识别。采用札达-泉水沟深地震测深资料，提取振幅、信噪比、主频、瞬时带宽、瞬时高频能量等地震属性参数，分析不同参数的物理含义，挑选其中对界面变化敏感的参数，对深地震测深资料进行预处理，并利用P波和S波的联合扫描，提高震相识别的准确性。走时互换结果显示，采用地震属性参数可有效提高震相拾取的准确性，进而提高后续地壳速度结构反演结果的精度。 相似文献
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根据近年来在全国开展的大城市活断层地震探测实践,在简要介绍各种地震勘探方法的基本原理和工作方法的基础上,着重分析了不同地震勘探方法的适用范围、获得的主要成果和所解决的主要问题。讨论了现阶段用地震勘探获取地壳结构和对不同深度断层定位的最佳组合方法,即对于有沉积覆盖的隐伏数百米深度至地表的断层,可用浅层地震勘探对其进行追踪,基底(埋深数公里)以上断层可采用高分辨地震折射探测;对于地壳中、深断裂应用反射地震勘探和深地震宽角反射/折射联合探测方法;还可以进一步采用三维深地震测深方法获得城市下方的三维结构和构造信息。采用这样的组合探测方法能够较好地获得断层在不同深度的产状与展布以及由深至浅完整的分布图像,并给出了应用实例 相似文献
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Xu Mingcai 《中国地震研究》2005,19(3):240-248
INTRODUCTIONLarge earthquake and ground surface dislocation produced by the sudden slip of an active faulthidden belowa city can result in serious disaster,bring about huge losses of people’s life and stateproperty,or even make a city destroyed instantly… 相似文献
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Exploration and Research of Deep Crustal Structures in the Zhangzhou Basin and Its Vicinity 总被引：1，自引：0，他引：1
Zhu Jinfang 《中国地震研究》2006,20(4):412-425
INTRODUCTIONThe Zhangzhou basinislocated onthe southeast coast of Fujian Province .Interms of geotectonicunits ,it lies in the east Fujian volcanic fault-depression zone between the Wuyi-Daiyun mountainupheaval zone and depression zone of Taiwan Straits of the south China block. In terms ofseismotectonics ,it islocatedinthe middle sectionof the southeasterncoastal seismic zone .In history,the area was influenced by repeated destructive earthquakes , and the seismic activity was closely… 相似文献
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THE CRUSTAL SHALLOW STRUCTURES AND FAULT ACTIVITY DETECTION IN XINYI SECTION OF TAN-LU FAULT ZONE 
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下载免费PDF全文 GU Qin-ping XU Han-gang YAN Yun-xiang ZHAO Qi-guang LI Li-mei MENG Ke YANG Hao WANG Jin-yan JIANG Xin MA Dong-wei 《地震地质》1979,42(4):825-843
The Tan-Lu fault zone is the largest active tectonic zone in eastern China, with a complex history of formation and evolution, and it has a very important control effect on the regional structure, magmatic activity, the formation and distribution of mineral resources and modern seismic activity in eastern China. Xinyi City has a very important position as a segmental node in the Shandong and Suwan sections of the Tan-Lu fault zone. Predecessors have conducted research on the spatial distribution, occurrence and activity characteristics of the shallow crustal faults in the Suqian section of the Tan-Lu belt, and have obtained some new scientific understandings and results. However, due to different research objectives or limitations of research methods, previous researches have either focused on the deep crustal structure, or targeted on the Suqian section or other regions. However, the structural style and deep-shallow structural association characteristics of Xinyi section of Tan-Lu belt have not been well illustrated, nor its activity and spatial distribution have been systematically studied. In order to investigate the shallow crustal structure features, the fault activities, the spatial distribution and the relationship between deep and shallow structures of the Xinyi section of the Tan-Lu Fault, we used a method combining mid-deep/shallow seismic reflection exploration and first-break wave imaging. Firstly, a mid-deep seismic reflection profile with a length of 33km and a coverage number greater than 30 was completed in the south of Xinyi City. At the same time, using the first arrival wave on the common shot record, the tomographic study of the shallow crust structure was carried out. Secondly, three shallow seismic reflection profiles and one refraction tomography profile with high resolution across faults were presented. The results show that the Xinyi section of Tan-Lu fault zone is a fault zone composed of five concealed main faults, with a structural pattern of “two grabens sandwiched by a barrier”. The five main faults reveal more clearly the structural style of “one base between two cuts” of the Tan-Lu fault zone. From west to east, the distribution is as follows: on the west side, there are two high-angle faults, F4 and F3, with a slot-shaped fault block falling in the middle, forming the western graben. In the middle, F3 and F2, two normal faults with opposite dip directions, are bounded and the middle discontinuity disk rises relatively to form a barrier. On the east side, F2 and F1, two conjugate high-angle faults, constitute the eastern graben. The mid-deep and shallow seismic reflection profiles indicate that the main faults of the Xinyi section of Tan-Lu fault zone have a consistent upper-lower relationship and obvious Quaternary activities, which play a significant role in controlling the characteristics of graben-barrier structure and thickness of Cenozoic strata. The shape of the reflective interface of the stratum and the characteristics of the shallow part of the fault revealed by shallow seismic reflection profiles are clear. The Mohe-Lingcheng Fault, Xinyi-Xindian Fault, Malingshan-Chonggangshan Fault and Shanzuokou-Sihong Fault not only broke the top surface of the bedrock, but also are hidden active faults since Quaternary, especially the Malingshan-Chonggangshan Fault which shows strong activity characteristics of Holocene. The results of this paper provide a seismological basis for an in-depth understanding of the deep dynamics process of Xinyi City and its surrounding areas, and for studying the deep-shallow tectonic association and its activity in the the Xinyi section of the Tan-Lu Fault. 相似文献
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使用重力资料推断解释地壳深部构造,关键在于浅层影响的消除。作者广泛收集整理了研究区的浅层地质资料,用三维重力正演方法逐层消除其影响,获得了一些较好的结果。在正演计算中发现,一些构造在下第三系以下已基本消失;而另一些构造却在此深度才逐渐显露。我们认为,浅层地质资料越完整准确,则三维重力正演计算的结果也将越好。在地壳深部构造的研究中,此方法与人工地震测深得到的地壳厚度基本一致,而花费却很低廉。它也是研究深浅构造关系的一种好方法。 相似文献
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ZHU Jinfang XU Xiwei ZHANG Xiankang HUANG Zonglin CHEN Xiangxiong FANG Shengming LIU Baojin ZHENG Rongzhang . Seismological Bureau of Fujian Province Fuzhou China . Institute of Geology China Earthquake Administration Beijing China . Research Center for Exploration Geophysics China Earthquake Administration Zhengzhou China . State Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing China 《中国科学D辑(英文版)》2005,48(7)
~~Joint exploration of crustal structure in Fuzhou basin and its vicinities by deep seismic reflection and high-resolution refraction as well as wide-angle reflection/refraction1.Ma,X.Y.,The Atlas of Lithospheric Dynamics of China(in Chinese),Beijing:Atlas Publishing Company,1989,1-68.
2.Liao,Q.L.,Wang,Z.M.,Wang,P.L.et al.,Explosion-generated earthquake study on crustal deep structure in Fuzhou-Quanzhou-Shantou region,Acta Geophysica Sinica(in Chinese),1988,31(3):270-280.
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本文通过深地震反射探测,获得了沈阳市区北部Moho面以上的地壳深部结构和剖面,上地壳复杂的断裂组合关系和下地壳高角度的深断裂共同构成了该区的深、浅构造关系,其结果为沈阳市活断层的地震危险性评价奠定了基础。 相似文献
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为了获得三维地震透射成像技术在活断层探测中的有效性和应用价值的评价,在银川盆地中北部布设了一个三维地震透射台阵,利用该台阵获得的基底初至折射波和莫霍界面反射波资料,采用有限差分反演、时间项反演和连续速度模型反演方法,对台阵区域基底及上地壳结构进行了分析.结果表明：研究区基底呈东西浅、中部深的界面形态,且西陡东缓,最深处大致位于芦花台至西大滩一带,埋深达7 km.芦花台断层、银川—平罗断层、黄河断层在研究区内均表现为北北东走向的速度差异条带,且断层两侧基底及沉积界面埋深存在显著变化.芦花台断层东倾,倾角较陡,延伸至研究区基底之下;银川—平罗断层倾向西,是一条超基底的隐伏断层;黄河断层西倾,延伸深度超过研究区基底.本探测结果证明,初至折射波与莫霍面反射波探测相结合的三维地震透射台阵技术能够给出研究区上地壳三维细结构图像,不仅可以揭示主要断裂的展布位置、浅部空间形态和特征,而且可以揭示断裂向基底之下的延伸状况. 相似文献