Ground Surface Ruptures and Near‐Fault,Large‐Scale Displacements Caused by the Wenchuan Ms8.0 Earthquake Derived from Pixel Offset Tracking on Synthetic Aperture Radar Images     

QU Chunyan  SHAN Xinjian  LIU Yunhu  ZHANG Guohong  SONG Xiaogang  ZHANG Guifang  GUO Liming  HAN Yufei 《《地质学报》英文版》2012,86(2):510-519

The 12 May 2008 Wenchuan Ms8.0 earthquake produced surface displacements along the causative fault, the Yingxiu–Beichuan Fault, which are up to several meters near the fault. Because of the large gradient, satellite synthetic aperture radar (SAR) interferometric data are strongly incoherent; the usual SAR interferometry method does not allow such displacements to be measured. In the present study, we employed another approach, the technique based on pixel offset tracking, to solve this problem. The used image data of six tracks are from the Advanced Land Observing Satellite, Phased Array type L-band Synthetic Aperture Radar (ALOS/ PALSAR) dataset of Japan. The results show that the entire surface rupture belt is 238 km long, extending almost linearly in a direction of 42° north–east. It is offset left laterally by a north–west-striking fault at Xiaoyudong, and turns at Gaochuan, where the rupture belt shifts toward the south by 5 km, largely keeping the original trend. In terms of the features of the rupture traces, the rupture belt can be divided into five sections and three types. Among them, the Beichuan–Chaping and Hongkou–Yingxiu sections are relatively complex, with large widths and variable traces along the trend. The Pingtong–Nanba and Qingping–Jingtang sections appear uniform, characterized by straight traces and small widths. West of Yingxiu, the rupture traces are not clear. North of the rupture belt, surface displacements are 2.95 m on average, mostly 2–3.5 m, with 7–9 m the maximum near Beichuan. South of the rupture belt, the average displacement is 1.75 m, dominated by 1–2 m, with 3–4 m at a few sites. In the north, the displacements in the radar line of sight are of subsidence, and in the south, they are uplifted, in accordance with a right-slip motion that moves the northern wall of the fault to the east, and the southern wall to the west, respectively. Along the Guanxian–Jiangyou Fault, there is a uplift zone in the radar line of sight, which is 66 km long, 1.5–6 km wide, and has vertical displacements of approximately 2 m, but no observable rupture traces.  相似文献   

海洋次表层叶绿素最大值的特征因子及其影响因素   总被引：2，自引：0，他引：2  

宫响  史洁  高会旺 《地球科学进展》2012,27(5):539-548

在多数情况下,海水中叶绿素垂直分布是不均匀的。次表层叶绿素最大值是其中较为常见的一种形式,普遍存在于大洋及沿岸海域。次表层叶绿素最大值层(SCML)的深度、厚度与强度是表征海洋次表层叶绿素最大值(SCM)现象的主要特征因子,受海洋水文环境、营养盐分布以及浮游植物种类等因素共同影响,在不同季节不同海区的分布有较大差异。总体上,相对近海,大洋中SCML特征因子的季节变化较小,SCML深度较大,厚度较大,强度较小。寡营养盐海区SCML深度及强度的影响因素研究已有较明确结论,SCML深度主要受物理因素(光照条件及水体混合程度)影响,而强度则受物理、生物因素(光照条件、水体混合程度或浮游动物摄食等)共同影响。近海富营养盐海区,SCML特征因子的影响因素研究较为薄弱。长时间序列、高分辨率观测站在相应海区的建立,对推进海洋SCM,尤其是近海SCM的研究有重要意义。卫星观测、现场观测和数学模型相结合,定量研究SCML特征因子与各物理、生物、化学因子的普适性关系,是进一步研究SCML特征因子的重要方向之一。  相似文献   

中扬子区东缘中古生界对冲构造体系形成与演化          下载免费PDF全文

佘晓宇  丁小辉  梁斌  龚晓星 《地质科学》2012,47(2):333-346

中扬子区东缘侏罗纪末期—白垩纪早期,受大洪山推覆区南西方向和江南雪峰逆冲推覆区北西方向的强烈挤压,形成了压扭性狭长的对冲构造体系; 两大推覆区的形成主要受深、浅变质岩结晶基底内幕两套拆离滑脱层系的作用,导致沉积盖层压缩沿基底面、志留系底面、泥盆系底面多层次滑脱推覆,产生了多样的挤压和压扭构造类型及其样式; 由造山带向盆内构造变形具有渐变的特点,为不对称式的仰冲(根带)—楔状掩冲(中带)—滑脱推覆(锋带)—对冲带; 持续压扭作用导致产生系列北东向左行走滑断裂将对冲构造体系分割; 白垩纪晚期—下第三纪,挤压转换为伸展环境,断裂负反转回滑成为中新生代断陷主控断裂,认为大洪山推覆区锋带已处于通海口—杨林尾—汉南一线,主体由于受洪湖走滑断裂和通海口断裂回滑的影响,接受了上白垩统—第四系沉积,仅保留了东、西两端弧形构造带古生界出露的构造面貌。  相似文献   

Utilization of an H-reversal trajectory of a solar sail for asteroid deflection     

Sheng-Ping Gong  Jun-Feng Li  Xiang-Yuan Zeng School of Aerospace  Tsinghua University  Beijing  China 《中国天文和天体物理学报》2011,(10)

Near Earth Asteroids have a possibility of impacting the Earth and always represent a threat. This paper proposes a way of changing the orbit of the asteroid to avoid an impact. A solar sail evolving in an H-reversal trajectory is utilized for asteroid deflection. Firstly, the dynamics of the solar sail and the characteristics of the H-reversal trajectory are analyzed. Then, the attitude of the solar sail is optimized to guide the sail to impact the target asteroid along an H-reversal trajectory. The impact...  相似文献   

武当-桐柏-大别成矿带铜矿成矿规律     

龚银杰 《地质与勘探》2014,50(5):902-909

武当-桐柏-大别成矿带可分为南秦岭造山带、北淮阳构造带、桐柏-大别构造带三个二级构造单元,在南秦岭造山带广泛分布变质热液型铜矿,北淮阳构造带内产出VMS型、岩浆熔离型及斑岩型铜矿,桐柏-大别构造带则分布有岩浆热液型和矽卡岩型铜矿。构造单元的性质对区内产出的铜矿类型具有较强的控制作用。变质热液型铜矿主要与浅变质作用有关,变质流体以断层为运移通道并最终就位于黑色岩系内的次级断层。VMS型、岩浆熔离型、斑岩型铜矿与岩浆作用密切相关,产出在岩体内部及与围岩的接触带。岩浆热液型及矽卡岩型铜矿形成于岩浆作用晚期阶段,分布在岩体与围岩接触带及附近构造裂隙带等部位。  相似文献   

Efficiency assessment of the energy consumption and economic indicators in Beijing under the influence of short-term climatic factors: based on data envelopment analysis methodology     

Zaiwu Gong  Yue Zhao  Xinming Ge 《Natural Hazards》2014,71(2):1145-1157

In this paper, the data envelopment analysis (DEA) method is introduced to analyze the input–output efficiency of energy consumption and economic indicators in Beijing city under the influence of short-term climatic factors. Total energy consumption, fixed asset investment, average temperature, precipitation, sunshine hours, average wind velocity and the average pressure being employed as the input variables, gross domestic product (GDP) and per capita disposable income being employed as the output variables, effective technology and the validity of the scale of DEA of 31 decision-making units (DMUs) under the influence of the short-term climatic factors are analyzed, and the inefficient DMUs are improved. Empirical analysis shows that both energy consumption and economic growth are sensitive to short-term climate condition, and the reasonable employing of extreme climatic conditions is a question worthy of consideration. This study provides effective basis for the scientific and reasonable arrangement of Beijing city’s short-term climatic resources and energy–economic development.  相似文献   

Meteorological and environmental effects on manufacturing in Jiangsu,China     

Wei Sun  Lianshui Li  Zaiwu Gong 《Natural Hazards》2014,71(2):1107-1123

This paper studies the border effects and sensitivity of the economic output of manufacturing in Jiangsu, China, caused by meteorological and environmental factors. The meteorological data, environmental data and annual manufacturing data of Jiangsu from 1993 to 2011 are used as input for this paper. Based on the Douglas production function and the grey correlation analysis method, this paper discusses the typical relationship among meteorological disaster factors, environmental regulations and the economic output of manufacturing in Jiangsu, China. The empirical analysis shows that the development of typical manufacturing in Jiangsu, China, is influenced by meteorological and environmental factors.  相似文献   

Co-integration analysis between GDP and meteorological catastrophic factors of Nanjing city based on the buffer operator     

Chonglan Guo  Xiaoxia Xu  Zaiwu Gong 《Natural Hazards》2014,71(2):1091-1105

This paper analyzes the relationship between meteorological catastrophic factors and gross domestic product (GDP) growth rate of Nanjing city (China). The sample spans the period 1980–2010, including GDP growth rate and meteorological catastrophic factors (extreme precipitation, extreme temperature and extreme wind speed). We utilize econometric methods to take co-integration analysis and Granger causality test among GDP growth rate and the time series of meteorological catastrophic factors of Nanjing city processed by buffer operators. Finally, the paper shows the short-term changes in minimum atmospheric pressure, extreme high temperature, and minimum relative humidity, which has a positive impact on GDP; the cumulative effect of extreme precipitation and GDP affects each other to some extent, they are mutually Granger causes. Moreover, at the 95 % confidence level, we believe that maximum wind speed is the Granger causation of GDP growth rate.  相似文献   

The comprehensive risk evaluation on rainstorm and flood disaster losses in China mainland from 2004 to 2009: based on the triangular gray correlation theory     

Yue Zhao  Zaiwu Gong  Wenhao Wang  Kai Luo 《Natural Hazards》2014,71(2):1001-1016

In this paper, we introduce the gray correlation method of risk evaluation in meteorological disaster losses based on historical disaster data in China (mainland) and apply the improved gray relational analysis model (the triangular gray relational model) to the risk evaluation of rainstorm and flood disaster losses. In addition, we divide the risk grade standards of rainstorm and flood disaster losses according to 186 rainstorm and flood disaster data of four optimization indexes (disaster area, suffered population, collapsed houses, and direct economic losses), evaluate the extent of dynamic rainstorm and flood disaster losses in 31 provinces of China (Hong Kong, Macao, and Taiwan exclusive) comprehensively, and draw China’s zoning map of rainstorm and flood disaster from 2004 to 2009. The method provides reasonable and effective references for national disaster preventions which can be used in other researches focused on risk evaluation of meteorological disaster losses.  相似文献   

Risk assessment of the city water resources system based on Pansystems Observation-Control Model of Periphery     

Qiang Fu  Fanli Gong  Qiuxiang Jiang  Tianxiao Li  Kun Cheng  He Dong  Xiaosong Ma 《Natural Hazards》2014,71(3):1899-1912

Study on risk assessment of water resources system is the key to ensure the water resources security and its sustainable utilization. Under the principles of sustainable utilization of water resources, with the thinking of the risk, the Pansystems Observation-Control Model of Periphery is applied to risk assessment of water resources system, and the model is based on the periphery theory and pansystems theory, with the observation-control risk analysis technology as the technical core. According to the synchronized analysis of the risk and gain of the five sustainable utilization schemes of water resources of Kiamusze in Heilongjiang, the best one for Kiamusze was confirmed and also opens a new way to research in the field of risk assessment of water resources system.  相似文献