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本文论述了影响城市工程物探探测效果的主要因素,并根据实际工作条件,为最大程度提高采集精度,采用浅层地震勘探和地震映像两种方法探测了千佛山断裂在济南市区内同一地点的隐伏位置及产状。并且在断层两盘布置钻孔,验证探测结果的可靠性。综合分析认为,物探结果表现了较高的信噪比和分辨率,充分说明这两种方法在城市工程物探中有较好的适用性。 相似文献
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河西务断裂活动性的综合探测研究 总被引:1,自引:1,他引:1
河西务断裂为河西务构造带的东缘断裂,总体走向北东,倾向南东,向北延伸与廊固凹陷内的横向断层(桐柏断裂)小角度相接,向南延伸与牛东断裂相接,为廊固凹陷与武清凹陷的分界断裂,隐伏于冀中凹陷覆盖层之下。本文通过浅层地震勘探和钻孔联合剖面探测,结合年代样品测试,对河西务断裂的活动性和滑动速率进行了综合研究,揭示断裂上断点埋深约150m或以浅,第四系底界面的垂直错距为20—45m,断裂的最新活动时代为晚更新世早期,晚更新世以来的平均垂直滑动速率为0.03mm/a,中更新世晚期以来的平均垂直滑动速率为0.11mm/a。 相似文献
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天津汉沽隐伏断裂属于滨海平原区隐伏断裂。本文采用化探、浅层地震勘探和联合钻孔剖面探测等方法,并结合年代样品测试对汉沽断裂进行了综合探测研究,首次查明了汉沽断裂的准确空间位置和晚第四纪活动性。探测结果表明,汉沽隐伏断裂最新上断点埋深25. 8m,断距为2. 15m。结合光释光年代样品测试结果,推断其最新活动时代为49. 3ka ~ 65kaBP,属晚更新世中期活动断裂。由于该断层是与主断层倾向相反的次级断层,可能并不是震源断层错动在地表的直接反映,同时汉沽断裂晚更新世早期以来的平均滑动速率为0. 063mm / a,明显低于海河断裂东段晚更新世以来0. 141mm / a 的平均滑动速率,这都表明汉沽隐伏断裂的活动强度并不是很大,应是一具有中等活动强度的活动断裂。 相似文献
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从重力场、地磁场和地热场等方面分析了山西断陷带地球物理场所具有的特征,论述了地球物理场特征及其揭示的深部构造与强震活动的关系,初步建立了山西断陷带强震发生的模式,指出,与强震活动密切相关的区域地球物理场特征及深部构造,是进行地震预报和地震区划等不可缺少的依据,也是今后进一步研究地震成因必须十分重视的问题. 相似文献
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综合物探方法在人工洞室探测中的应用效果分析 总被引:1,自引:0,他引:1
随着人们对地下溶洞和人工洞室的探测精度的要求越来越高,单一的物探方法并不能满足高精度勘探的要求。本文以对某地一人工洞室投入磁法、电法、地震波法的探测结果为例,通过对探测结果的对比分析,说明在探测此类问题中如何合理地选择物探方法,对后期的工程建设有一定的指导作用。 相似文献
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The eastern Anatolia is a continental collisional zone between the Arabia-Eurasia plates and is currently being accompanied by the westward escape of the Anatolian crustal block to the west-southwest along two major strike-slip fault zones, the NATF and the EATF. Although these major fault zones have experienced historical earthquakes with moderate to high magnitude, notably there is a low seismicity zone on the active EATF between the Bitlis and Pötürge massifs. The low seismicity zone is characterized by thinner crustal structure relative to its environs, the shallow Curie Point Depth (SCPD, ca 12–14 km in between 39–40°E and 38.5–39°N in the easternmost part of the Anatolian plate) and moderate to high b values (more than 0.7). We consider that the shallow CPD and moderate to high b values in the low seismicity zone characterized by thinner crustal area are closely related with the higher thermal structure of the crust, which most probably resulted from crust-hot asthenospheric mantle interactions. 相似文献
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分析了陕西周至及附近的地震活动及有感地震的等震线特征,认为该区以孤立型小震或小震群活动为主,在较大范围内,地壳应力还是处于调整状态,近期发生中强以上地震的可能性不大。 相似文献
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1900年以来全球地震活动的初步分析 总被引:3,自引:2,他引:3
20世纪50年代和60年代,是全球地震矩的大释放阶段。从60-80年代地震矩释放速率呈下降的趋势。90年代后,地震矩释放速率有所回升。从50-80年代,中国大陆及东半球的地震矩释放速率有明显的下降趋势。一次9级左右地震的成丛是20世纪地震活动的明显特点。 相似文献
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From August 1976 to June 1979, more than 220 seismic events were recorded by a 7-station network operating over an active gas field in France. 120 earthquakes with magnitudes greater than 1.0 were selected for a detailed study in order to understand the seismic response to a decrease in the gas reservoir pressure of 50 MPa. Composite focal mechanisms were determined for these events. We found that where preexisting fractures were known from well-logs, faults with the most favorable orientation were reactivated. In the part of the gas field where no preexisting faults were known, orientation of the fracture planes was close to the orientations of stratigraphic interfaces.Our kinematic model, constrained by the distribution of the earthquakes and their focal mechanisms, consists of the downward dropping of a block located close to the top of the gas field. The main faults, as defined by the spatial density of the seismic activity, define the limits of this block. The displacements observed along these faults can be either normal or reverse mechanism, dependent on the preexisting orientation of each fault. Another important result is the evidence that the depletion of the gas reservoir exerts the major influence on local seismic displacements, obscuring the effect of regional setting. 相似文献