Study of the Seismicity of Strong Earthquakes in the Yunnan Area     

Huangfu Gang 《中国地震研究》2006,20(4):449-459

INTRODUCTIONYunnanis located in the east margin of the collision zone between the India Plate and theEurasian Plate on the Chinese Continent , where crustal movement is violent and moderate-strongearthquakes are frequent withlarge magnitudes and wide distributions .It is also a place of particularinterest to geo-science researchers both at home and abroad. Since 1970 , 8 earthquakes withmagnitude 7·0 have occurred here .It is a perfect site to study seismicity.Whether or not seismicit…  相似文献   

Correlation Between Local Slip Rate and Local High-frequency Seismic Radiation in an Earthquake Fault     

Alexander A. Gusev  Eugenia M. Guseva  Giuliano F. Panza 《Pure and Applied Geophysics》2006,163(7):1305-1325

For any earthquake, the slipping fault and the source of high-frequency seismic waves, by and large, coincide. On a more local scale, however, the areas of high seismic slip rate and of increased high-frequency radiation output (seismic luminosity) need not match. To study in some detail how slip rate and seismic luminosity are interrelated, a systematic study is performed that uses 251 records of teleseismic P waves from 23 intermediate-depth earthquakes of magnitude 6.8 and above. From a broadband trace we extract two time histories: (1) displacement and (2) 0.5–2.5 Hz band-passed and squared velocity, or ``HF power', and calculate correlation coefficient, ρ between the two. To reduce the bias related to formation of P coda, a special procedure is applied to data. We estimated the average value ρ = 0.52 (range of event averages 0.35 to 0.65) for the correlation coefficient between the radiated time histories for displacement and ``HF power', which is considerably below the ``ideal' value of unity. We argue that the same or even lower value characterizes the degree of slip rate - seismic luminosity correlation at the fault. Two factors may contribute to the revealed decorrelation: (1) random fluctuations of observed HF power (inevitable for a signal with a limited bandwidth), and (2) the genuine mismatch of slip rate and mean luminosity. We show that these factors, acting separately, would result in the ρ values equal to, correspondingly, 0.72 and 0.80. We also show that genuine decorrelation is statistically significant. We conclude that the observed values of ρ indicate genuine differences between the distributions of the slip rate and the seismic luminosity over the fault area. These results provide important constraints both for the accurate wide-band simulation of strong ground motion and for theoretical dynamic source models.  相似文献   

王庄油田强水敏性稠油油藏热采开发研究   总被引：4，自引：0，他引：4  

SHI Dian-hai )) ) Nanjing Institute of Geology  Palaeotology  Chinese Academy of Sciences  Nanjing  ) Geological Scientific Research Institute of Shengli Oilfield Company  SINOPEC  Dongying 《地层学杂志》2007,(Z2)

王庄油田位于山东东营凹陷北部陡坡带,其主力含油层系沙一段黏土含量高达13%,水敏指数超过70%,属强水敏性稠油油藏。强水敏性成为制约其能否采用注蒸汽开发的关键。为此,在分析形成储层强水敏地质原因的基础上,采用水敏流动试验、高温物理模拟实验和数值模拟等方法,利用激光拉曼、X-衍射、核磁和CT等技术手段,开展了储层水敏机理、热采过程中骨架矿物、黏土矿物和储层物性变化规律研究。结果表明:随温度的升高骨架矿物逐步溶蚀、膨胀性黏土矿物发生转化;在温度高于250℃时渗透率可恢复到原始值的80%左右,证明了该类油藏热采开发的可行性;结合热采过程中温度场的变化,建立了强水敏稠油油藏热采储层物性变化模式。该成果在矿场应用中取得理想效果,可为同类油藏的开发提供借鉴。  相似文献   

孟加拉湾风暴造成红河州一次强降水的诊断分析     

李艳春  叶文群 《云南地理环境研究》2007,(Z1)

应用MICAPS常规资料结合FY-2卫星云图,通过天气分析与物理量诊断分析方法,对红河州2007年5月16～18日的持续性强降水天气过程进行了分析。这次过程主要影响天气系统为初夏孟加拉湾风暴、700 hPa切变线及地面冷锋,冷空气侵入孟加拉湾风暴外围环流导致强降水发展并持续。冷锋切变南下有利于水汽凝结量的增加及强降水天气发生发展环境的形成。孟加拉湾风暴带来的充沛水汽输送和强烈的上升运动与不稳定大气为持续强降水发生发展提供了有利条件。卫星云图上强对流云团覆盖区与红河州强降水区相对应。  相似文献   

1997～2005年中国大陆肘≥6强震危险区预测检验与总结研究     

黄圣睦  董瑞英 《四川地震》2007,(2):1-7

作者在《中国强震活动图像与地震预报》中运用地震活动图像分析方法，对中国大陆1997～2005年M≥6强震危险性做出了趋势预测，经过预测期内强震实况检验，取得了较好效果。本文对预测方法思路进行了回顾性研究，总结了基本经验和教训，对于提高强震趋势预测研究水平有一定参考价值。  相似文献   

深孔勘察中强自然造斜地层的防斜纠斜工艺技术措施     

李宝辉  刘志会 《探矿工程》2007,34(7):8-9

在强自然造斜地层的深孔勘察施工中，孔斜问题一直是影响钻孔质量和勘察成果质量的重要因素。以穿越恒山山脉铁路隧道深孔勘察为例，介绍了在自然造斜严重的片麻岩地层中采用有效钻孔防斜措施和螺杆钻具纠斜方法，保证了勘察钻孔的质量。  相似文献   

云南地震类型分区特征研究   总被引：7，自引：0，他引：7       下载免费PDF全文

皇甫岗  秦嘉政  李忠华  邬成栋 《地震学报》2007,29(2):142-150

对云南地震序列和强震震源机制的分析与研究表明,云南地区具有较明显的地震类型分区特征.总体上云南全区地震断层以走向滑动为主，地震序列以主余震型为主.考虑到非走滑地震断层和非主余震型地震序列所占的比例，可以将云南地区划分为4个具有不同特点的分区: 滇中(A1)走滑-主余震型区、 滇西北(A2)斜滑-震群型区、滇西(B1)走滑-双震型区和滇西南(B2)准走滑-主余震型区.   相似文献   

中国大陆与周边板块边界强震活动的互动关系探讨     

王双绪  王继英  薛富平 《国际地震动态》2007,(6):18-24

分析中国大陆与周边板块边界、尤其是西部地震“大三角”地区强震活动的关系认为,中国大陆与周边板块边界带的强震活动之间存在互动关系,而不完全是后者对前者的触发作用。进而根据中国大陆地震构造环境、大尺度地壳运动变形动态与强震活动状况,研究和探讨了这种“互动关系”可能的构造动力机理和我国大陆未来地震活动的发展趋势。  相似文献   

基于小波分析提取的云南强震数字化形变异常特征   总被引：2，自引：0，他引：2  

刘强  宋治平 《中国地震》2007,23(3):310-318

运用小波分析理论及其时频分析方法,阐述了提取高频信息与低频信息的方法,并用该方法提取了2001年以来云南地区强震(MS≥6)前数字化形变异常。结果表明,在MS≥6地震前,震中附近(<250km)的倾斜、应变和重力等形变信号出现周期为3~11天的异常信息;重力和倾斜异常出现较早,可作为中短期指标,应变异常出现较晚,可用作短临指标;震源区最先出现应变异常,应变异常可作为未来强震震中的判定指标。这些强震前数字化形变异常特征对该地区未来强震三要素的中短临判定具有较好的参考作用。  相似文献   

Basement interface structural characteristics beneath Jiashi strong earthquake swarm area in Xinjiang, China   总被引：1，自引：0，他引：1  

徐朝繁段永红  田晓峰潘纪顺张建狮  胡修奇 《地震学报(英文版)》2007,20(5):507-512

The seismic data obtained from high resolution seismic refraction profile in Jiashi strong earthquake swarm area in Xinjiang, China were further processed with ray hit analysis method and more complete basement interface struc-tural characteristics beneath Jiashi strong earthquake swarm area were determined. The results show that there are two clear basement interfaces at the upper crust in Jiashi strong earthquake swarm area. The first one with buried depth ranging from 2.6 km to 3.3 km presents integral and continuous structure, and it appears an inclined plane interface and smoothly rises up toward Tianshan Mountain. The second basement interface with buried depth from 8.5 km to 11.8 km, is the antiquated crystalline basement of Tarim basin. Near the post number of 37 km, the bur-ied depth of the crystalline basement changed abruptly by 2.5 km, which maybe result from an ultra crystalline basement fault. If taking this fault as a boundary, the crystalline basement could be divided into two parts, i.e. the southwestern segment with buried depth about 11.5 km, and the northeastern segment with buried depth approxi-mately from 8.5 km to 9.0 km. That is to say, in each segment, the buried depth changes not too much. The north-east segment rises up as a whole and upheaves slightly from southwest to northeast, which reflects the upper crustal deformation characteristics under the special tectonic background at the northwestern edge of Tarim basin.  相似文献