四川汶川大地震的构造分析   总被引：6，自引：0，他引：6  

王振荣  兰江华 《矿物岩石》2008,28(2):1-5

2008年5月12日在汶川映秀(北纬31.0°,东经103.4°)发生8级大地震,而后发生万余次余震,其最大震级为6.4级.此次地震属主震-余震型地震.通过构造分析认为.汶川大地震是构造地震,主要受龙门山断裂带的强烈活动控制.它是一种板内地震,其动力来源来自印度板块与欧亚板块的碰撞.而成都平原处于稳定地块中,尽管离震中较近,然受地震的影响有限,是比较安全的.  相似文献   

汞元素的石油地质意义     

李广之  袁子艳  庄原  江浩 《物探与化探》2008,32(2):143-146,185

油气中都含有汞元素组分,汞的物理化学性质决定其可以从油气藏中向上垂向运移,根据采样介质类型及样品预处理的手段不同,地表中汞的分析方法可分为壤气、热释汞及土壤总汞分析方法。壤气汞、热释汞及土壤总汞指标都有着很好的示油气意义,同时也有着示断裂带的地质意义。  相似文献   

Impact of the tsunami and earthquake of 26th December 2004 on the vital coastal ecosystems of the Andaman and Nicobar Islands assessed using RESOURCESAT AWiFS data   总被引：2，自引：0，他引：2  

Anjali Bahuguna  Shailesh Nayak  Dam Roy 《International Journal of Applied Earth Observation and Geoinformation》2008,10(2):229-1

Tsunami waves struck the Indian coast on 26th December 2004 affecting the Andaman and Nicobar group of islands. A quick assessment of the status of the vital coastal ecosystems has been made using pre- and post-tsunami Advance Wide Field Sensor (AWiFS) data of Indian satellite RESOURCESAT with an accuracy of 87–90% and the Kappa ranging from 0.8696 to 0.9053. Among the coastal ecosystems the coral reefs have suffered the maximum with the Nicobar reefs (69% eroded and 29% degraded) bearing the brunt more than the Andaman reefs (54% eroded and 22% degraded). Significant improvement to the condition of the reef damaged due to backwash has been noted. About 41% of the Sentinel reef area has undergone significant improvement. The continuance of the erosion of the southwestern Andaman reefs is due to the impact of recurring earthquakes. The impact on mangroves of both the groups of islands has been due to uprooting as well as inundation of seawater and resulting stagnation. Changes are expected in community structure of mangroves as a result of tsunami.  相似文献   

Estimation of LAI and above-ground biomass in deciduous forests: Western Ghats of Karnataka, India     

Rangaswamy Madugundu  Vyjayanthi Nizalapur  Chandra Shekhar Jha   《International Journal of Applied Earth Observation and Geoinformation》2008,10(2):211-1

This study demonstrates the potentials of IRS P6 LISS-IV high-resolution multispectral sensor (IGFOV  6 m)-based estimation of biomass in the deciduous forests in the Western Ghats of Karnataka, India. Regression equations describing the relationship between IRS P6 LISS-IV data-based vegetation index (NDVI) and field measured leaf area index (ELAI) and estimated above-ground biomass (EAGB) were derived. Remote sensing (RS) data-based leaf area index (PLAI) image is generated using regression equation based on NDVI and ELAI (r² = 0.68, p ≤ 0.05). RS-based above-ground biomass (PAGB) image was generated based on regression equation developed between PLAI and EAGB (r² = 0.63, p ≤ 0.05). The mean value of estimated above-ground biomass and RS-based above-ground biomass in the study area are 280(±72.5) and 297.6(±55.2) Mg ha⁻¹, respectively. The regression models generated in the study between NDVI and LAI; LAI and biomass can also help in generating spatial biomass map using RS data alone. LISS-IV-based estimation of biophysical parameters can also be used for the validation of various coarse resolution satellite products derived from the ground-based measurements alone.  相似文献   

"5.12"汶川大地震震中区映秀镇地震灾情及次生地质灾害遥感初步调查   总被引：4，自引：0，他引：4  

王治华  周英杰  徐斌  贾斌 《国土资源遥感》2008,(2):1-6

"5.12"四川汶川8级大地震发生后,中国国土资源航空物探遥感中心立即采用"赛斯纳"高空遥感飞机,携带高清晰彩色数码相机及先进的POS系统,迅速获取了重灾区的航摄图像数据。本文以震中附近的映秀镇地区为例,简要介绍了以该高质量航摄数据为基础,采用数字滑坡技术,快速进行震后重灾区灾情及次生地质灾害遥感调查的成果。  相似文献   

基于MODIS数据的雪面温度遥感反演(英文)     

Ji Zhou  Yunhao Chen  Jing Li  Yan Tang 《地球空间信息科学学报》2008,11(4):247-251

On the basis of simplification of the Planck function in a low temperature range, this paper revises the practical split-window algorithm and presents a method for retrieving snow surface temperature （Ts） based on MODIS data in the middle-latitude region. The application of this method in Qinghai Lake region reveals that it is feasible for the retrieval of Ts. Results of correlation analysis indicate that there was strong negative relationship between Ts and altitude. By analyzing three typical areas in which land cover was relatively homogenous, this paper discusses the relationship between Ts and normalized difference snow index （NDSI） and then presents a new concept named ＂NDSI-Ts space＂.  相似文献   

区域地质灾害危害程度等级划分探讨     

王昌平 《中国地质灾害与防治学报》2008,19(2):142-146

区域性地质灾害危害程度等级尚无比较科学的划分方法。通过福建省区域地质灾害危害程度等级划分的探讨,采用单位面积地质灾害造成的人员死亡数、财产损失值作为“地质灾害模数”,对区域地质灾害危害程度等级进行划分,判别不同区域地质灾害严重程度,为区域地质灾害防治决策提供科学依据。  相似文献   

贝加尔裂谷系及邻区断裂现今活动变化及成因(英文)     

S.I. Sherman　E.A.Gorbunova 《地学前缘》2008,15(3):337-347

已有的地质和地球物理方法无法对年、月、旬等现今时间尺度上的断层活动变化进行有效预测。运用基于地震活动定量指数运算程序的地理信息技术可以解决这个问题。这种方法被应用于贝加尔裂谷系(BRS)及邻区的研究当中。研究发现,断层活动变化发生在以几年为周期的时间尺度上,这无法用区域应力场的变化进行合理解释。沿着穿越贝加尔裂谷系的剖面编制了活动断层图以及地震活动定量指数曲线。提出的这种方法可以根据地震活动定量指数对活动断层进行仔细的分类,从而为解决地震中期预报相关问题开辟了重要途径。这种方法还被用来研究断层现今活动的时空变化和形成机制。研究发现,在实时尺度上断层活动具有高频发生的特征,这种现象可能是由于脆性岩石圈板内和块体内部运动产生的慢变形波的干扰导致的。利用变形波的通过速度可以对活动断层进行分组,各组具有不同的地质和地球物理特征参数,同时还可以对变形波波前的方向以及某一区域内主要断层在实时间隔内(地质上的瞬间)的活动情况进行预测。  相似文献   

汶川特大地震中山岭隧道变形破坏特征及影响因素分析   总被引：22，自引：0，他引：22  

李天斌 《工程地质学报》2008,16(6):742-750

汶川大地震造成位于震中附近的都江堰-汶川公路多座隧道严重受损。本文通过现场调研、资料收集与分析,将地震区山岭隧道变形破坏的基本类型概括为洞口边坡崩塌与滑塌、洞门裂损、衬砌及围岩坍塌、衬砌开裂及错位、底板开裂及隆起、初期支护变形及开裂等。分析其影响因素,认为发震断裂的次级断层、基覆界面、洞口不稳定斜坡、高地应力环境下的软弱围岩对隧道强烈震害具有控制作用。以汶川地震给予隧道抗震的启示,建议强震区的山岭隧道应将洞口边坡防护、洞口明洞和洞门结构作为一个系统进行综合设计,在条件允许的情况下尽可能采用削竹式洞门结构;隧道穿越活动断裂带的次级断层时在其两侧一定范围内二次衬砌应采用钢筋混凝土结构;基覆界面、围岩软岩与硬岩之间的过渡地带、围岩质量突变地带等应采用改善围岩力学性质且让其渐变的措施进行处理。  相似文献   

烟台市城市土地可持续利用评价     

郑璐璐  ;张鲁府 《山东地质》2008,(12):27-29

以烟台市为例,从生态环境协调性、经济可行性、社会可接受性等方面,构建了2004年城市土地可持续利用评价的指标体系,采用特尔斐等方法计算了其可持续利用度。结果表明,烟台城市土地利用目前仍处于可持续利用起步阶段。  相似文献