最小二乘配置下的天山地区应变场特征分布   总被引：1，自引：0，他引：1       下载免费PDF全文

李杰  王晓强  刘代芹  帕尔哈提·再努拉  陈述江 《地震学报》2015,37(1):103-112

利用已有的GPS观测数据,借助球面最小二乘配置方法对天山地区的GPS速度场进行研究,得到了研究区域应变场的空间分布特征．其最大主压应变表明,大地震多发生在主压应变快速交替变化的地带,主压应变最大值主要分布于西南天山与帕米尔弧及塔里木西北交汇的地区,强地震(M7.0—8.0)基本发生在该区域．面膨胀值表明天山地区应变呈挤压收缩的特征．   相似文献   

Shelf-basin exchange in the Laptev Sea in the warming climate: a model study     

Vladimir Ivanov  Pavel Maslov  Yevgeny Aksenov  Andrew Coward 《地球物理与天体物理流体动力学》2015,109(3):254-280

GCM-based forecast simulations predict continuously increasing seasonality of the sea ice cover and an almost ice-free, summer-time, Arctic Ocean within several decades from the present. In this study we use a primitive equation ocean model: NEMO, coupled with the sea ice model LIM2, to test the hypothesis that under such an increased range in seasonal ice cover the intensity of shelf-basin water exchange will significantly increase. We use the simulated results for the Laptev Sea from a global model run 1958–2007 and compare results for two years with anomalously high and low summer sea ice extents: 1986–1987 and 2006–2007. The shelf–basin fluxes of volume, heat and salt during specific seasons are evaluated and attributed to plausible driving processes, with particular attention to dense water cascading. Analyses of the model temperature distribution at the depth of the intermediate maximum, associated with Atlantic Water, have shown a marked increase of the amount of the local origin cold water in late winter 2007 in the region, where dense water typically appears as a result of its formation on the shelf and subsequent downslope leakage. Calculation of the shelf-basin exchange during March-May in both years confirmed a substantial increase (a factor of two) of fluxes in “ice-free” 2007 compared to the “icy” 1987. According to several past model studies, dense water production on Arctic shelves in winter driven by ice freezing and brine rejection is not likely to cease in a warmer climate, but rather to increase. There is also observational evidence that cascading in the seasonally ice covered seas (e.g. the Barents Sea) is much more efficient than it is in the permanently ice covered Arctic Ocean, which supports these model results.  相似文献   

某区水库大坝近期形变特征研究     

刘代芹  布艾杰尔·库尔班  方伟  朱治国 《内陆地震》2008,22(1):55-65

通过利用GPS和水准测量手段对某区水库大坝表面运动进行监测,获取大量的野外监测数据。通过内业计算得出每期的大坝各变形点的三维坐标,并结合、利用近3期的数据资料对比,求出各点的形变量。最终通过计算、分析得出水库主坝、东副坝及北副坝3个坝体的稳定性。  相似文献   

Impact of spatial correlation of ground motions on seismic damage for residential buildings in Bucharest,Romania     

Pavel  Florin  Vacareanu  Radu  Calotescu  Ileana  Sandulescu  Ana-Maria  Arion  Cristian  Neagu  Cristian 《Natural Hazards》2017,87(2):1167-1187

Natural Hazards - This paper focuses on the investigation of seismic risk for residential buildings situated in Bucharest, the capital city of Romania. With a population of nearly 2 million...  相似文献   

Long-lasting Cadomian magmatic activity along an active northern Gondwana margin: U–Pb zircon and Sr–Nd isotopic evidence from the Brunovistulian Domain,eastern Bohemian Massif     

Soejono  Igor  Janoušek  Vojtěch  Žáčková  Eliška  Sláma  Jiří  Konopásek  Jiří  Machek  Matěj  Hanžl  Pavel 《International Journal of Earth Sciences》2017,106(6):2109-2129

International Journal of Earth Sciences - Cadomian magmatic complexes of the Brunovistulian Domain crop out at the eastern termination of the Bohemian Massif. However, the age, nature and...  相似文献   

基于RS和GIS的艾比湖区域景观格局动态变化研究   总被引：3，自引：0，他引：3  

谢霞  王宏卫  塔西甫拉提·特依拜 《中国沙漠》2010,30(5):1166-1173

以生态环境脆弱的艾比湖区域为研究对象,基于1990、2001年和2007年3期Landsat TM/ETM+遥感数据资料,采用支持向量机（SVM）方法,进行景观分类与制图,利用ArcGIS制作了艾比湖区域的景观类型转移矩阵及转移过程空间格局图,定量研究了艾比湖区域1990—2007年景观格局的时空变化特征,同时分析了景观类型转入/转出贡献率。结果表明：①在整个研究时段内耕地的面积在不断增加,其中2001—2007年间耕地的年平均变化率为6.79%。未利用地的面积有所减少。②在转入和转出过程中,耕地和草地之间的转化比较明显;城乡建设用地的增加,主要是由耕地和未利用地转化而来的;生命支持能力脆弱的未利用地与草地之间的转换较为密切。③绿洲景观有整体向东迁移的趋势;林地在2001—2007年间迁移的距离最远,为6.1450 km。④景观类型转入贡献率占优势的为耕地,转出贡献率占优势的为未利用地。  相似文献   

Improvements of drilling fluid processing for cable-suspended electromechanical drills     

YU Dahui  Pavel Talalay  XU Huiwen  CAO Pinlu  Mikhail Sysoev  HAN Lili  HAN Junjie 《世界地质(英文版)》2013,(2):99-105

Deep ice drilling in Polar Regions plays a key role in paleo-climate, microbiological and glaciological researches. For deep ice and subglacial coring the special purpose-built electromechanical cable-suspended drills with bottom-hole circulation are designed and explored. Used at present drilling fluid circulation systems are specified by very high fluid wastes during processing. Measurements in deep drilling projects in Antarctic and Greenland ice sheets showed that 25%-40% of the drilling fluid, pumped into the hole, is retrieved to the surface with cable and drill, and up to 45% of retrieved fluid goes to waste. This leads not only to increasing of the fluid consumption and cost of the project in general but also to severe contamination of air, surface and near-surface snow-firn layers at the drilling site. In order to reduce wastes and environmental impact, it is proposed to modify drilling fluid processing system by avoiding of evaporation and leakages of fluid as far as practicable. Drilling fluid is prepared and pumped into the hole according to predetermined program on semiautomatic mode, and volume and density of blended and pumped into the hole drilling fluid are measured continuously. Components of the drilling fluid are stored and mixed in the special closed containers equipped by pressure relief valves. Separation of drilling fluid from ice cuttings is carried out by two steps: firstly, fluid is separated with hydro extractor and then with thermal separator. To reduce the amount of removed drilling fluid with cable special squeezing collar is installed on the borehole mouth. All these arrangements are able to decrease drilling fluid wastes in many times.  相似文献   

新疆应急指挥技术系统远程访问控制方法及实现     

兰陵  宋立军  哈斯高娃  热孜万古力·艾买提  陈勇 《内陆地震》2012,26(3):250-256

分析了"新疆抗震救灾指挥部技术系统"软件功能、接口及运行模式,根据目前技术系统运行的安全要求和现实需求,提出了应急指挥中心技术系统软件远程触发功能设计方案,并通过RouterOS、防火墙规则、日志管理、电源控制等软件和计算机网络设置实现系统软件远程触发以及远程查看。通过测试,该设计方案在确保安全性和可操作性的前提下,大大提高了应急指挥的效率,同时也为我们实现远程调试打下一定的基础。  相似文献   

Magnetic susceptibility of cambisol profiles in the vicinity of the Vír dam,Czech Republic     

Marta Chlupáčová  Jaromír Hanák  Pavel Müller 《Studia Geophysica et Geodaetica》2010,54(1):153-184

Magnetic susceptibility of 72 cambisol profiles from the vicinity of the Vír dam, NW Moravia was measured. The enhanced susceptibility of topsoil, particularly of the horizon O, was assessed from the aspect of vegetation setting and magnetic mineralogy. Magnetic susceptibility variations with field and temperature as well as frequency dependent susceptibility were applied to indicate magnetic carriers. It was found that the enhanced magnetic susceptibility is caused very likely by the presence of maghemite and magnetite of various grain sizes. Magnetic minerals are pedogenic in origin in all three horizons, while in the O and A horizons they are mostly anthropogenic in origin. Magnetic susceptibility was correlated with contents of trace elements Mo, Cu, Pb, Zn, Ag, As, Cd, Sb, Bi, Hg, Se, furthermore with TOT/C, TOT/S, and ¹³⁷C. The close association of susceptibility with Pb, Sb and Hg, or also with Mo, As, Se and their similar depth variations suggest a slight anthropogenic input in soils from a long-distant source. The same is valid for ¹³⁷C, its strong correlation with magnetic susceptibility has been found.  相似文献   

Magnetostratigraphy and fold tests from Račiška pečina and Pečina v Borštu caves (Classical Karst,Slovenia)     

Petr Pruner  Nadja Zupan Hajna  Andrej Mihevc  Pavel Bosák  Otakar Man  Petr Schnabl  Daniela Venhodová 《Studia Geophysica et Geodaetica》2010,54(1):27-48

Clastic and chemogenic cave sediments were sampled and analyzed from Račiška pečina and Pečina v Borštu caves of southwestern Slovenia. Samples were subjected to both thermal and alternating field demagnetization; specimens belonging to the same sample of the same layer produce identical results. Unblocking temperatures of 540 to 560°C on average suggests magnetite as the principal carrier of magnetization. These directions also pass a reversals test indicating the demagnetization results are free of secondary overprints and have adequately averaged out paleosecular variation. Normally magnetized clays containing fauna belonging to the MN17 mammal biozone at a depth of ∼ 4 m in Račiška pecina cave indicate these clays were deposited at the beginning of the Olduvai subchron (1.95 Ma). Correlation with the Geomagnetic Polarity Time Scale (GPTS) indicates the base of the speleothems in Račiška pečina terminate in the upper part of subchron C2An.3n with numerous breaks in deposition, lasting up to 250 ka and more. Therefore rates of speleothem growth cannot be calculated. Fold tests on dome-like stalagmites of differing sizes and ages (Pleistocene, Pliocene) from the two caves indicate the domelike structures are primary.  相似文献