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961.
George C.Lee 《地震工程与工程振动(英文版)》2010,9(2):145-145
<正>Dear JEEEV Contributors,Readers and Friends,The world community was shocked and deeply saddened two years ago by the 512 disaster and massive losses in Sichuan caused by the Wenchuan earthquake.To commemorate 相似文献
962.
963.
GEOMORPHIC FEATURES OF THE SHULE RIVER DRAINAGE BASIN IN QILIANSHAN AND ITS INSIGHT INTO TECTONIC IMPLICATIONS
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SU Qi YUAN Dao-yang XIE Hong SHAO Yan-xiu LIANG Ming-jian. Lanzhou Institute of Seismology China Earthquake Administration Lanzhou China . Lanzhou National Observatory of Geophysic 《地震地质》2016,38(2):240-258
Because of the strong uplift of the Qilian Shan since late Cenozoic,the drainage basins that are derived from the mountains have undergone strong tectonic deformation.So the typical geomorphology characteristics of these drainage basins may indicate the strong tectonic movement in the region.For example,the Shule River drainage basin,which originates from the western part of the Qilian Shan owns unique geomorphology characteristics which may indicate the neotectonic movement.
Stream networks of the Shule drainage basin extracted from the DEM data based on GIS spatial analysis technology are graded into five levels using Strahler classification method.Four sub-catchments,numbered 1,2,3 and 4 are chosen for detailed analysis.Furthermore,the four sub-catchments,the hypsometric integral curves,Hack profiles,SL index and average slope of the Shule drainage basin are determined by GIS tools.In addition,we analyzed the slope spectrum of the Shule drainage basin.
The average elevation of the Shule drainage basin is very high,however,the slope of the drainage basin is very low,the gentle slope occupies so large area proportion that the slope spectrum shows a unimodal pattern and a peak value is in low slope region (0°~5°),so tectonic movement has a strong influence on the drainage basin.Under the intensive impact of the tectonic movement of the active fault and regional uplift,the hypsometric integral curve is sigmoid,revealing that the Shule drainage basin is in the mature stage.The Hack profile is on a convex,the longitudinal profile is best fitted by linear fitting and the abnormal data of the SL index of the Shule River has a good fit with the section through which the active fault traverses,that means the tectonic movement of the active fault has strong influence on the river's SL index.It is worth noting that lithologic factors also have great impact on the river geomorphology in some sections.
According to the above analysis,we recognize that in the interior of active orogen,the evolution of river geomorphology usually is influenced by tectonic movement and reveals the regional neotectonics in turn. 相似文献
964.
GEOMORPHIC FEATURES OF THE HEIHE RIVER DRAINAGE BASIN IN WESTERN QILIAN SHAN-HEXI CORRIDOR AND ITS TECTONIC IMPLICATIONS
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Using quantitative geomorphic factors for regional active tectonic evolution is becoming more and more popular. Qilian Mountains-Hexi Corridor which locates in the northern edge of Qinghai-Tibet plateau is the most leading edge of the plateau's northward extension. The uplift rate of all segments and the intensity of influence from tectonic activity are the important evidences to understand the uplift and extension of the plateau. Heihe River Basin is located at the northern piedmont of the western segment of Qilian Mountains, the development of the rivers is influenced by the tectonic activity of the Qilian Mountains, and the unique river morphology is important carriers of the regional tectonic uplift.
Geomorphologic indexes such as hypsometric integral, geomorphologic comentropy and river longitudinal profiles were extracted by GIS tools with free access to the Shuttle Radar Topography Mission(SRTM)DEMs, and according to the different expression of the geomorphological indexes in the Heihe River Basin, we divided the drainage basin into two parts and further compared them to each other.
Recent studies reveal that obvious differences exist in the landscape factors(hypsometric integral, geomorphology entropy and river profiles)in the east and west part of the Heihe Basin. The structural intensity of the west part is stronger than that of the east, for example, in areas above the main planation surface on the western part, the average HI value is 0.337 8, and on the eastern part the HI value is 0.355. Accordingly, areas under the main planation surface are just on the contrary, indicating different structural strength on both sides. Similar phenomenon exists in the whole drainage basins. Furthermore, by comparing the fitting river profiles with the real river profiles, differential uplift is derived, which indicates a difference between west and east(with 754m on the western part and 219m on the east). Comprehensive comparison and analysis show that the lithologic factors and precipitation conditions are less influencing on the geomorphic factors of the study area, and the tectonic activities, indicated by field investigation and GPS inversion, are the most important element for geomorphic evolution and development. The variation of the geomorphologic indexes indicates different tectonic strength derived from regional structures of the Qilian Shan. 相似文献
965.
新疆地区县(市)地震应急能力指标体系的建立与区域差异初探 总被引:2,自引:2,他引:0
从新疆地区地震活动性、灾害背景及区域协同联动应急模式出发,在遵循科学性、系统优化和可操作性及区域特性等原则的基础上,采用层次分析法建立了县级行政单元的地震应急能力评价指标体系;继而建立了基于基础设施条件、基础人力物力财力、(县级)专项能力和专项经验及基础环境背景4个一类指标集的县(市)绝对地震应急能力综合评价模型,并根据新疆地区4类人员问卷调查资料,计算和分析了样本支持条件下各指标的权重及结果,将其应用在新疆地区县(市)地震应急能力等级划分中。结果表明,地震应急能力的空间分布格局的产生与区域经济发展水平和地理位置等方面所具备的优势是相适应的,安居富民工程对提升区域地震应急能力发挥了重要作用,少数民族聚集区应急能力有待加强,寒旱、高海拔地区等特殊地理因素影响不可忽视。 相似文献
966.
The combination of magnetotelluric survey and laboratory measurements of electrical conductivity is a powerful approach for exploring the conditions of Earth’s deep interior. Electrical conductivity of hydrous silicate melts and aqueous fluids is sensitive to composition, temperature, and pressure, making it useful for understanding partial melting and fluid activity at great depths. This study presents a review on the experimental studies of electrical conductivity of silicate melts and aqueous fluids, and introduces some important applications of experimental results. For silicate melts, electrical conductivity increases with increasing temperature but decreases with pressure. With a similar Na+ concentration, along the calc-alkaline series electrical conductivity generally increases from basaltic to rhyolitic melt, accompanied by a decreasing activation enthalpy. Electrical conductivity of silicate melts is strongly enhanced with the incorporation of water due to promoted cation mobility. For aqueous fluids, research is focused on dilute electrolyte solutions. Electrical conductivity typically first increases and then decreases with increasing temperature, and increases with pressure before approaching a plateau value. The dissociation constant of electrolyte can be derived from conductivity data. To develop generally applicable quantitative models of electrical conductivity of melt/fluid addressing the dependences on temperature, pressure, and composition, it requires more electrical conductivity measurements of representative systems to be implemented in an extensive P-T range using up-to-date methods. 相似文献
967.
中生界侏罗系是鄂尔多斯盆地重要的石油勘探与开发目的层之一,侏罗系油藏受前侏罗纪古地貌影响较为显著。本文通过流体包裹体特征分析、均一化温度测定和包裹体丰度(GOI)分析、定量颗粒荧光(QGF、QGF-E)研究以及储集层自生伊利石K-Ar定年等实验方法和手段的应用,对鄂尔多斯盆地侏罗系油气包裹体特征进行了精细描述及定量化分析研究,揭示了侏罗系油藏形成时间、充注过程及油气包裹体与油气运移、成藏的关系。研究结果表明:侏罗系油藏存在晚期充注,早期充注少或油藏遭受调整,早期生成的烃类现今仅以沥青的形式赋存,现今烃类流体主要为晚期成藏的产物。侏罗系石油大规模充注期为(108.3±2.0)~(116.5±2.0)Ma(早白垩世中期),具有垂向运移聚集的特点。鄂尔多斯盆地侏罗系油藏早期受岩性和构造双重控制,晚期构造活动调整了油气藏的形态及局部富集。侏罗系在晚期成藏过程中没有形成过叠合连片的大规模的油藏,只在局部构造上形成规模较小的“小而肥”的独立油藏。 相似文献
968.
969.
介绍了广播星历精度评估的基本原理和方法,并利用2013-01~2015-04共28个月的广播星历数据,分析比较了北斗不同类型卫星的轨道精度、钟差精度及整体精度的短期和长期变化趋势。结果表明,GEO卫星广播星历的轨道精度约为1.8 m,钟差精度优于6 ns;IGSO和MEO广播星历的轨道精度优于1.2 m,钟差精度优于4 ns,整体上优于GEO卫星。从长期变化趋势来看,北斗广播星历的精度有逐渐提高的趋势。 相似文献
970.
分析和计算宽频带静电反馈倾斜仪测量中正交方向上的倾斜对测量结果的影响。结果表明,正交方向的倾斜使测量结果产生误差,需对仪器加以改进,以减小正交耦合误差。 相似文献