3-D seismic structure of the source area of the 1993 Latur, India, earthquake and its implications for rupture nucleations   总被引：1，自引：0，他引：1  

S. Mukhopadhyay  O.P. Mishra  D. Zhao  J.R. Kayal 《Tectonophysics》2006,415(1-4):1-16

The Latur earthquake (M_w 6.1) of 29 September 1993 is a rare stable continental region (SCR) earthquake that occurred on a previously unknown blind fault. In this study, we determined detailed three-dimensional (3-D) P- and S-wave velocity (V_p, V_s) and Poisson's ratio (σ) structures by inverting the first P- and S-wave high-quality arrival time data from 142 aftershocks that were recorded by a network of temporary seismic stations. The source zone of the Latur earthquake shows strong lateral heterogeneities in V_p, V_s and σ structures, extending in a volume of about 90 × 90 × 15 km³. The mainshock occurred within, but near the boundary, of a low-V_p, high-V_s and low-σ zone. This suggests that the structural asperities at the mainshock hypocenter are associated with a partially fluid-saturated fractured rock in a previously unknown source zone with intersecting fault surfaces. This might have triggered the 1993 Latur mainshock and its aftershock sequence. Our results are in good agreement with other geophysical studies that suggest high conductivity and high concentration of radiogenic helium gas beneath the source zone of the Latur earthquake. Our study provides an additional evidence for the presence of fluid related anomaly at the hidden source zone of the Latur earthquake in the SCR and helps us understand the genesis of damaging earthquakes in the SCR of the world.  相似文献   

西北旅游落后现状的突破及列车旅游的新思路--兼论"西部之星"旅游列车的产品设计   总被引：1，自引：0，他引：1  

刘睿文  吴殿廷 《地域研究与开发》2006,25(1):88-92

近几年，西北地区的旅游业虽然取得了很大的成绩，但其发展相对于东部地区却显得落后，其主要原因之一就是西北地区的旅游资源过于分散，景点间距过大，由此导致游览行程过长，游览内容单薄，这在客观上影响了游客的选择。而与此同时，在国外，列车旅游早已作为各国旅游业的重要旅游产品为世人所熟知。文章从分析我国西北旅游业发展的现状入手，针对景点分散这一制约我国西部旅游业发展的客观不利因素，肯定了开发旅游列车产品的思路。作者以西北地区为例，结合目前我国旅游专列发展现状，提出开通“西部之星”旅游列车的构想，并进行了初步的设计。  相似文献   

山区生态县区域协调发展的机制构建--以粤北始兴县为例   总被引：1，自引：0，他引：1  

税伟  陈烈  唐常春 《山地学报》2006,24(1):70-78

区域协调机制在不同类型地域和一种类型地域的不同的发展阶段是不同的。始兴县作为一个典型的山区生态县,工业进入加速发展时期,在此经济发展阶段的区域协调问题主要表现在:与外部区域经济、社会发展差距拉大,工业化与流域生态环境保护的矛盾已开始凸现,县政府协调区域发展的财政能力较低,区域协调机制不健全等。由此对始兴县的区域协调机制进行建构:建立健全多层次的区域协调机构;加大纵向和横向政府财政转移支付的力度;加强与相邻相关地区的协调;实施区域空间管治协调,保护城乡生态环境;科学合理选择产业,大力发展循环经济;全县推行绿色GDP考核等。  相似文献   

灌丛对川西北高寒草甸土壤资源的影响   总被引：7，自引：1，他引：7  

刘长秀  张宏  泽柏 《山地学报》2006,24(3):357-365

以川西北高原红原县为研究区,用方格取样法,在相邻的高寒灌丛草地和高寒草甸样地中分别随机取0~20 cm土样50个,并分析了这些土样的土壤性状。利用SPSS(11.0)软件对实验数据进行了统计、分析和比较,研究了两个样地的各种土壤养分的平均含量、空间异质性和相关关系。结果表明,草甸样地的粘粒含量、Ptotal、Ntotal、ORG、Pavail、Navail、Kavail的含量都高于灌丛样地,且两样地速效养分差异极显著,但草甸样地土壤的ORG、Navail、Kavail的变异系数(CV)却明显小于灌丛样地,特别是Kavail的CV值,灌丛样地比草甸样地高出了53.37%;相关分析还表明,相对于草甸,灌丛样地中各养分元素之间的相关性明显增强。说明灌丛对高寒草甸土壤资源的异质性有明显的影响,其存在降低了草甸土壤养分的均值含量并增强了土壤养分的变异性和侵蚀潜力,不利于高寒草甸土壤养分的保持。  相似文献   

粤西地区县域城镇化发展探讨——以广东省高州市为例   总被引：1，自引：0，他引：1  

张志斌  雷春芳 《山地学报》2006,24(6):709-715

受地理条件、经济基础等因素的制约,粤西地区面临着城镇化进程滞后、整体发展层次偏低等一系列问题。加速推进县域城镇化是加快粤西地区经济发展,缩小与发达地区差距的内在要求和必然选择。以高州市为例,全面总结了粤西地区县域城镇化发展的特点及存在的主要问题,并在系统分析其城镇化发展机制的基础上,提出通过完善城镇体系,加强产业集聚,提升建设品位,增强城镇自我发展能力等促进县域城镇化发展。  相似文献   

紫色丘陵区水土保持林低效化的土壤成因     

何毓蓉廖超林  张保华 《山地学报》2006,24(B10):11-15

四川盆地紫色丘陵区的水土保持林低效化问题已较严重。研究了其土壤方面的成因。通过对土壤构造、土壤肥力特性、土壤结构性评价等研究，指出该区人工林地的土壤构造发育不正常，土壤腐殖质胶体积累量低。土壤结构质量差等林地土壤退化是土壤水土保持功能降低的主要原因。根据研究的初步结果，提出了相应的对策建议。  相似文献   

Climate change in Mt. Qomolangma region since 1971     

YANG Xuchao  ZHANG Yili  ZHANG Wei  YAN Yuping  WANG Zhaofeng  DING Mingjun  CHU Duo 《地理学报》2006,16(3):326-336

Using monthly average, maximum, minimum air temperature and monthly precipitation data from 5 weather stations in Mt. Qomolangma region in China from 1971 to 2004, climatic linear trend, moving average, low-pass filter and accumulated variance analysis methods, the spatial and temporal patterns of the climatic change in this region were analyzed. The main findings can be summarized as follows: (1) There is obvious ascending tendency for the interannual change of air temperature in Mt. Qomolangma region and the ascending tendency of Tingri, the highest station, is the most significant. The rate of increasing air temperature is 0.234 oC/decade in Mt. Qomolangma region, 0.302 oC/decade in Tingri. The air temperature increases more strongly in non-growing season. (2) Compared with China and the global average, the warming of Mt. Qomolangma region occurred early. The linear rates of temperature increase in Mt. Qomolangma region exceed those for China and the global average in the same period. This is attributed to the sensitivity of mountainous regions to climate change. (3) The southern and northern parts of Mt. Qomolangma region are quite different in precipitation changes. Stations in the northern part show increasing trends but are not statistically significant. Nyalam in the southern part shows a decreasing trend and the sudden decreasing of precipitation occurred in the early 1990s. (4) Compared with the previous studies, we find that the warming of Mt. Qomolangma high-elevation region is most significant in China in the same period. The highest automatic meteorological comprehensive observation station in the world set up at the base camp of Mt. Qomolangma with a height of 5032 m a.s.l will play an important role in monitoring the global climate change.  相似文献   

Ground motion scaling in the Marmara region, Turkey   总被引：1，自引：0，他引：1  

A. Akinci  L. Malagnini  R. B. Herrmann  R. Gok  M. B. Sørensen 《Geophysical Journal International》2006,166(2):635-651

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Investigating the lowermost mantle using migrations of long-period S–ScS data     

K. Chambers  J. H. Woodhouse 《Geophysical Journal International》2006,166(2):667-678

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Berriasian (Lower Cretaceous) brachiopods from the Crimea     

S. V. Lobatscheva  T. N. Smirnova 《Stratigraphy and Geological Correlation》2006,14(6):642-654

Four successive assemblages of Berriasian brachiopods distinguished for the first time in the Crimea are correlated with concurrent subdivisions of the ammonoid scale. Berriasian brachiopods are represented by 44 species of 27 genera and 14 families, which are most complete in terms of taxonomic composition as compared to other concurrent brachiopod faunas known elsewhere. The assemblages are dominated by local species. As is proved, the Berriasian brachiopods studied are appropriate for age determination, subdivision and correlation of their host deposits. Their geographic distribution that has been analyzed elucidates connections of the Berriasian sea basins within the Mediterranean paleozoogeographic region.  相似文献