Source characteristics of the Yutian earthquake in 2008 from inversion of the co-seismic deformation field mapped by InSAR     

Xinjian Shan  Guohong Zhang  Chisheng Wang  Chunyan Qu  Xiaogang Song  Guifang Zhang  Liming Guo 《Journal of Asian Earth Sciences》2011,40(4):935-942

On 21 March 2008, an Ms7.3 earthquake occurred at Yutian County, Xinjiang Uygur Autonomous Region, which is in the same year as 2008 Mw 7.9 Wenchuan earthquake. These two earthquakes both took place in the Bayar Har block, while Yutian earthquake is located in the west edge and Wenchuan earthquake is in the east. The research on source characteristics of Yutian earthquake can serve to better understand Wenchuan earthquake mechanism. We attempt to reveal the features of the causative fault of Yutian shock and its co-seismic deformation field by a sensitivity-based iterative fitting (SBIF) method. Our work is based on analysis and interpretation to high-resolution satellite (Quickbird) images as well as D-InSAR data from the satellite Envisat ASAR, in conjunction with the analysis of seismicity, focal mechanism solutions and active tectonics in this region. The result shows that the 22 km long, nearly NS trending surface rupture zone by this event lies on a range-front alluvial platform in the Qira County. It is characterized by distinct linear traces and a simple structure with 1–3 m-wide individual seams and maximum 6.5 m width of a collapse fracture. Along the rupture zone are seen many secondary fractures and fault-bounded blocks by collapse, exhibiting remarkable extension. The co-seismic deformation affected a big range 100 km × 40 km. D-InSAR analysis indicates that the interferometric deformation field is dominated by extensional faulting with a small strike-slip component. Along the causative fault, the western wall fell down and the eastern wall, that is the active unit, rose up, both with westerly vergence. The maximum subsidence displacement is ～2.6 m in the LOS, and the maximum uplift is 1.2 m. The maximum relative vertical dislocation reaches 4.1 m, which is 10 km distant from the starting rupture point to south. The 42 km-long seismogenic fault in the subsurface extends in NS direction as an arc, and it dipping angle changes from 70° near the surface to 52° at depth ～10 km. The slip on the fault plane is concentrated in the depth range 0–8 km, forming a belt of length 30 km along strike on the fault plane. There are three areas of concentrating slip, in which the largest slip is 10.5 m located at the area 10 km distant from the initial point of the rupture.  相似文献   

世界主要深水含油气盆地烃源岩特征   总被引：2，自引：1，他引：1  

范玉海  屈红军  张功成  冯杨伟  关利群  雷露 《海相油气地质》2011,16(2):27-33

对墨西哥湾、巴西东部大陆边缘、西非被动大陆边缘、澳大利亚西北陆架、挪威中部陆架、南海等六个地区的22个深水含油气盆地烃源岩特征(主力烃源岩形成的时代、构造背景、沉积环境、类型、地球学化指标等)的综合研究结果表明,世界深水含油气盆地主力烃源岩主要集中在白垩系,其次为第三系和侏罗系;裂谷期烃源岩占绝对优势,其次为被动陆缘期...  相似文献   

深水平台吸力沉箱基础工程地质问题分析     

曲延大  王建华 《海洋技术学报》2011,30(1):72-77

针对深水平台吸力沉箱基础,讨论了与沉箱安装有关的分析方法及涉及的工程地质参数,分析了承受竖向拉拔荷载、倾斜与水平荷载作用的吸力沉箱极限承载力的分析方法及涉及的工程地质参数,对与吸力沉箱设计有关的其它问题也进行了分析.在此基础上,阐明了与吸力沉箱设计有关的工程场地调查内容及需要确定的工程地质参数.其目的是为开发深水平台吸...  相似文献   

Erratum to: Using genetic algorithms to calibrate a dimethylsulfide production model in the Arctic Ocean     

瞿波 《中国海洋湖沼学报》2011,29(1):232-232

  相似文献   

Characteristics of sand damages and dynamic environment along the Tuotuohe section of the Qinghai-Tibet Railway     

KeCun Zhang  QingHe Niu  JianJun Qu  ZhengYi Yao  QingJie Han 《寒旱区科学》2011,3(2):0137-0142

Sand damages along the Qinghai-Tibet Railway occur frequently and have spread rapidly since it was completely opened to traffic in 2006. The goal of this study was to understand the effects of sand damages on the railway via meteorological data and in situ observation of wind-blown sand. We selected the Tuotuohe section of this railway as a typical research object, and we systematically investigated its characteristics of sand damages, drift potential, sand-driving wind rose, and their time variation. The direction of sand-drifting wind clearly varies with the season. In winter, the predominant wind blows from the west and lasts for three months, while in summer the frequency of northeasterly wind begins to increase and multi-directional winds also occurs in July. The drift potential in this area is 705.81 VU, which makes this a high-energy wind environment according to Fryberger’s definition. The directional variability (RDP/DP) is 0.84 and the resultant drift potential is 590.42 VU with a resultant direction of 89.1°.  相似文献   

Evolution process of sediment supply for debris flow occurrence in the Longchi area of Dujiangyan City after the Wenchuan earthquake     

Ming Chang  Chuan Tang  Huayong Ni  Yongping Qu 《Landslides》2015,12(3):611-623

  相似文献   

Mechanism of strata deformation under protective seam and its application for relieved methane control     

Wei Yang  Bai-quan Lin  Yong-an Qu  Shuai Zhao  Cheng Zhai  Li-li Jia  Wu-qiang Zhao 《International Journal of Coal Geology》2011,85(3-4):300-306

In this paper, an equation correlated with normal stress and permeability was developed and FLAC^3D software was used to investigate the rock mass stress evolution and distribution to understand the methane flow characteristics. Research results show that the rock mass under the protective coal seam can be divided into three belts (zones) in the vertical direction, including total de-stressed belt, vertical de-stressed belt and original stress belt. Methane in the total de-stressed belt can flow into the working face of protective coal seam by its own pressure gradient. Methane in the vertical de-stressed belt can only be extracted by boreholes. In the horizontal direction, the rock mass was also divided into five zones, including original zone, compression zone, expansion zone, recovering zone and re-compacted zone, which have been proved correct by the field experiments. The rock mass permeability in the de-stressed belts doesn't increase until stepping into the expansion zone, and from then on higher concentration of methane can be extracted. The methane in original regions is difficult to extract because rock stresses stay the same. The division of “three belts and five zones” reveals the rock mass stress and permeability distribution and evolution and supplies theoretical guidance for relieved methane control.  相似文献   

U–Pb and Re–Os geochronology and geodynamic setting of the Dabaoshan polymetallic deposit, northern Guangdong Province, South China     

Lei Wang  Mingan Hu  Zhen Yang  Wenjun Qu  Jinlong Xia  Kaixu Chen 《Ore Geology Reviews》2011,43(1):40-49

The Dabaoshan polymetallic deposit in northern Guangdong Province contains iron, copper, lead, zinc, molybdenum, tungsten and sulfur mineral resources. Porphyry-type Mo(W) and skarn-type Mo-W mineralization occurs along the internal and external contact zones of the granodioritic porphyry, respectively. LA-ICP-MS U–Pb dating of zircons from two granodioritic porphyry samples yielded a weighted mean ²⁰⁶Pb/²³⁸U age of 175.8 ± 1.5 Ma (MSWD = 0.037) and 175.0 ± 1.7 Ma (MSWD = 0.41). They can be pooled together to yield a combined weighted age of 175.4 ± 1.6 Ma (MSWD = 0.26), which is interpreted as the emplacement age of the granodioritic porphyry. Re–Os dating of three molybdenite samples from porphyry and skarn ores yielded consistent model ages of 163.2 ± 2.3 Ma to 165.2 ± 2.4 Ma, with a weighted mean of 163.9 ± 1.3 Ma (MSWD = 0.81), which is the age of Mo–W mineralization. These ages are consistent with the molybdenite Re–Os model age (164.7 ± 3 Ma) measured by Mao et al. (2004a) for the stratiform Cu–Pb–Zn orebody, and they can yield a weighted mean of 164.0 ± 2.5 Ma (MSWD = 0.16). This implies that Mo–W and Cu–Pb–Zn mineralization in the Dabaoshan polymetallic deposit are the products of one mineralization event. The mineralization in the deposit coincides closely with that of Mo-polymetallic mineralization (164–149 Ma) elsewhere in the Nanling region, comprising an important polymetallic metallogenic belt of south China, and corresponds to the second episode of Mesozoic metallogenesis in South China. Combined with previous studies, we suggest that the Dabaoshan polymetallic deposit is related to post-collisional lithosphere extension in the Nanling region of South China. Geological data and Pb isotopic evolution diagrams, together with stable isotopic data of fluid inclusions (δ¹⁸O = − 3.75–7.0‰, δD = − 50.7 to − 56.1‰) and ore sulfides (δ³⁴S = − 2–3‰), suggest a genetic relationship between the Dabaoshan polymetallic deposit, the granodioritic porphyry and the dacitic porphyry. These data, combined with the Re content (64.7 to 102.4 ppm) of molybdenite, indicate that the ore-forming components were derived from mixed crustal and mantle sources.  相似文献   

中国大陆地震条带统计特征分析   总被引：6，自引：0，他引：6       下载免费PDF全文

李莹甄  王海涛  邬成栋  王想  冯建刚  曲延军  王行舟 《地震学报》2011,33(5):568-581

对中国大陆具备相对完整资料的327次M≥5.0地震,分5个工作区进行了统一要求的地震条带图像扫描,发现96次中强震前存在条带图像,约占研究地震总数的29％.其中震前有条带地震与研究地震的比例分别为:华北地区30％,华东南区29％,川滇地区41％,青藏高原西北缘24％,新疆地区16 ％.中强震前出现条带比例最低的是新疆,...  相似文献   

VP型宽频带倾斜仪映震能力分析     

王强  孟建国  吕春帅  曲保安  卢双苓  孙豪 《地震地磁观测与研究》2011,32(4):94-98

根据所掌握的仪器映震能力、震前(后)大震特殊捕捉现象,以及对相同地震不同仪器映震的对比,可以看出,VP型宽频带垂直摆倾斜仪具备前兆仪器捕捉(反映)地震孕育及地震发生的相关作用,能够正确、客观的作用于地震前兆数据产出,对地震预测研究具有深远影响.  相似文献