三维分块倾斜界面的反演及其应用   总被引：3，自引：0，他引：3       下载免费PDF全文

赖晓玲  郑需要  张先康 《地震工程学报》1997,19(3):63-68

介绍了利用反射波走时反演介质层速度和包含直立断层的三维界面的计算方法．对各层界面利用多个倾斜或平界面方程来描述．给出了数值计算实例．结果表明，反演解与真模型很接近，说明计算方法是有效的．利用该方法处理了唐山地震区的ＰｍＰ反射波资料，获得了该区域莫霍界面的三维分块形态．唐山附近莫霍界面错断与该区域１９７６年唐山地震及一系列余震的发生有密切的联系．  相似文献   

Quantitative Tectonic Markers of Large Coastal Earthquakes in Fujian, Guangdong, Taiwan and Hainan——with a Discussion of Qualitative Indicators     

Bi Fuzhi Yuan Youshen Institute of Crustal Dynamics  State Seismological Bureau  Beijing 《《地质学报》英文版》1997,71(4):395-406

This paper expounds the quantitative tectonic indicators and some qualitative indicators of large earthquakes in the coast areas of Fujian, Guangdong, Taiwan and Hainan. The main quantitative indicators include uplift amplitude of the Moho, Quaternary and Late Holocene coasts. The paper also gives a brief account of the research method on quantitative indicators of surface uplifted zones. Taiwan is a famous neotectonic zone and an area of large earthquakes in the world. There is only one large-earthquake area in each of Fujian, Guangdong and Hainan Provinces. Along the coast large earthquake areas there are certainly many remains of crustal activity. Among these remains, coast activity, taking the sea level as the accurate marker horizon, can determine not only the amplitude of coastal elevation and subsidence in a certain period, but also the cycle and rate of positive or negative movements.  相似文献   

A new method of testing pile using dynamic P-S-curve made by amplitude of wave train     

Hu Yi-li  Xu Jun  Duan Yong-kong  Xu Zhao-yong  Yang Run-hai  Zhao Jin-ming 《地震学报(英文版)》2004,17(6):725-734

A new method of detecting the vertical bearing capacity for single-pile with high strain is discussed in this paper. A heavy hammer or a small type of rocket is used to strike the pile top and the detectors are used to record vibration graphs. An expression of higher degree of strain (deformation force) is introduced. It is testified theoretically that the displacement, velocity and acceleration cannot be obtained by simple integral acceleration and differential velocity when long displacement and high strain exist, namely when the pile phase generates a whole slip relative to the soil body. That is to say that there are non-linear relations between them. It is educed accordingly that the force P and displacement S are calculated from the amplitude of wave train and (dynamic) P-S curve is drew so as to determine the yield points. Further, a method of determining the vertical bearing capacity for single-pile is discussed. A static load test is utilized to check the result of dynamic test and determine the correlative constants of dynamic-static P(Q)-S curve. Foundation item: Key projects of the tenth Five-year Plan of Yunnan Province (documented Yunnan district [2002]54-02-02) and Geophysical Society of Yunnan Province.  相似文献   

Geometric form of Haiyuan fault zone in the crustal interior and dynamics implications   总被引：1，自引：0，他引：1  

Fan Ji-chang  Li Song-lin  Zhang Xian-kang  Liu Ming-jun 《地震学报(英文版)》2004,17(1):43-51

The deep seismic reflection data on profile HY2 are reprocessed by the method of simultaneous inversion of velocity distribution and interface position. By the travel-time inversion with the data of the diving wave Pg and fault plane reflection wave, we determine the geometric form and velocity of Haiyuan fault zone interior and surrounding rock down to 10 km depth. The measured data show that the amplitudes have strong attenuation in the range of stake number 37–39 km, suggesting the fault zone has considerable width in the crustal interior. The results of this paper indicate that to the north of the fault zone the crystalline basement interface upheaves gradually from southwest to northeast and becomes shallow gradually towards northeast, and that to the south of the fault zone, within the basin between Xihua and Nanhua mountains, the folded basement becomes shallow gradually towards southwest. The obliquity of the fault zone is about 70° above the 3 km depth, about 60° in the range of the 3–10 km depths. From the results of this paper and other various citations, we believe that Haiyuan fault zone is in steep state from the Earth’s surface to the depth of 10 km. Foundation item: Joint Seismological Science Foundation of China (201001) and State Key Basic Research Development and Programming Project (95-13-02-02). Contribution No. RCEG200308, Exploration Geophysical Center, China Earthquake Administration.  相似文献   

Seismic reflection imaging of an oceanic detachment fault: Atlantis megamullion (Mid-Atlantic Ridge, 30°10′N)     

J.P. Canales  B.E. Tucholke  J.A. Collins 《Earth and Planetary Science Letters》2004,222(2):543-560

We present multichannel seismic reflection data collected over the Atlantis megamullion, at the eastern ridge-transform intersection of Atlantis fracture zone on the northern Mid-Atlantic Ridge, and over its conjugate crust. These data image for the first time the internal structure of a young, well-developed megamullion dome formed by tectonic extension across a long-lived oceanic detachment fault. The exposed, corrugated detachment-fault surface exhibits a sharp, coherent reflection that contrasts with less organized reflectivity of surrounding basaltic seafloor. At the termination of the megamullion the fault is imaged ∼13 km along-strike beneath a volcanic hanging-wall block at a sub-seafloor depth of 0.2-0.5 s two-way travel time, reaching north as far as 30°19′N. The eastward dipping of the fault beneath the hanging-wall block is estimated to be ∼6-14°. The corrugated fault surface is underlain by a continuous, strong, and relatively smooth reflection (D) at 0.2-0.25 s sub-bottom below the central axis of the dome. This reflection deepens up to 0.6 s sub-bottom beneath the western slope and it appears to intersect the seafloor on the eastern slope. We suggest that Atlantis massif formed by sequential slip on two different detachment faults that merged at depth, with breakaways as little as ∼2 km apart. The initial detachment is represented by reflection D, and the second corresponds to the presently exposed fault surface. In this interpretation, much of the sliver between the faults is interpreted to be strongly serpentinized peridotite with reduced seismic velocity; it lies in contact with less altered, higher-velocity mantle below the first detachment, resulting in the strong, smooth character of reflection D. Mantle rocks exposed in the megamullion indicate that the feature formed during a period of extreme tectonic extension and probably limited magmatism. In conjugate crust corresponding to termination of the megamullion, observed sub-bottom reflections are interpreted as base of seismic layer 2A. This layer is as thick as or thicker (∼570-900 m) than layer 2A in normal Atlantic crust, and it suggests that relatively normal crustal accretion occurred by the time the megamullion stopped forming.  相似文献   

载荷试验确定基床系数修正方法的讨论   总被引：1，自引：0，他引：1  

李伟  高广运  邱畅 《上海国土资源》2004,(4):15-18

Winkler地基模型是目前工程界应用最广的一种地基模型，但对其关键参数——基床系数k的确定，许多文献的表述并不一致。该文在大量试验资料的基础上，通过对该问题的深入研究，阐明了通过载荷试验确定基床系数修正方法的有关概念。对于砂性土地基，载荷板试验得出的基准基床系数仅需要进行基础大小修正，而对于粘性土地基，则需要进行基础大小和基础形状两项修正。  相似文献   

松辽盆地南部深层地震资料处理方法研究     

李振江  赵奎  杨秋莹  李春雨  张术权 《世界地质》2004,23(2):179-182,186

针对松辽盆地南部深层原始地震记录接收能量弱、信噪比低、各种干扰波严重和地表条件多变等存在严重的静校正问题，尝试利用CGG、Foucs、Grisys、Promax等多套处理系统的优势模块对跨工区二维大吾4面进行深部地层的折射波静校正、反褶积、剩余静校正、DipMoveOut、偏移等关键技术的联合处理方法试验研究，形成了一套针对松辽盆地南部深层地震资料处理的有效方法。  相似文献   

水质大涡模拟数学模型研究   总被引：2，自引：0，他引：2       下载免费PDF全文

张昌兵  熊朝坤  桂林  刘华  莫政宇 《水科学进展》2004,15(4):431-435

建立了基于弱可压缩流基础上的水质大涡模拟数学模型及污染物质扩散系数与平均运动的关系。数值计算采用有限体积法和预测校正法,固壁边界条件采用"部分滑移条件"。并应用该模型对重庆嘉陵江、长江两江交汇段的流场,污染物质浓度分布进行了计算,计算结果与实测值比较吻合。研究表明,横向扩散与流动状态有关,当支流流量相对较小时,横向扩散较弱,形成岸边污染带,当支流流量相对较大时,横向扩散较强,污染带向江心移动。  相似文献   

鄂尔多斯盆地苏里格庙气田上古生界盒8段地质与地球物理响应特征     

王志雄  徐国盛 《物探化探计算技术》2004,26(1):27-32

苏里格庙气田主要产气层为上古生界石盒子组盒8段，属于三角洲平原分流河道沉积。复合砂体近南北向展布；单砂体的厚度变化大，非均质性明显，储渗变化大。盒8段含气砂岩在AVO资料上有明显反映；在综合测井资料上，盒8段表现出自然伽玛测井值、密度测井值、补偿中子测井值都偏低，电阻率、声波时差测井值较高，出现了大幅度的自然电位异常。利用核磁共振测井技术测得苏里格庙区某井盒8段3555．9m～3559．6m为气层，3560．6m～3572m为气水层，与生产实践吻合得很好。  相似文献   

青藏高原隆升与环境效应   总被引：17，自引：1，他引：17  

黎敦朋  肖爱芳  李新林  周小康 《陕西地质》2004,22(1):1-10

通过对青藏高原北缘库木库里盆地新生代沉积建造、孢粉、阶地热年龄、沉积响应的调查研究，得出青藏高原新生代的渐新世、上新世和更新世一全新世形成的三套磨拉石建造代表青藏高原最强烈的三次隆升作用；自渐新世以来到上新世晚期高原隆升幅度达1500～2000m，更新世、全新世高原隆升了约2500m，46．4Ka．Bp至今高原隆升了约44m；青藏高原的隆升速率由渐新世开始有愈来愈强烈的趋势，预示青藏高原的隆升是一个多阶段、不等速和非均变的复杂过程；根据库木库里盆地沉积演化揭示青藏高原的隆升经历了早中渐新世早期隆升期、晚渐新世——早中新世早期稳定剥蚀夷平期、早中新世中晚期小幅隆升期、中中新世较稳定剥蚀夷平期、晚中新世振荡隆升期、上新世快速隆升期、更新世一全新世强烈隆升期共七个隆升阶段；并探讨了高原隆升引起的气候干燥、生物灭绝、荒漠化等多种环境效应。  相似文献