Factors Controlling Seismic Susceptibility of the Sele Valley Slopes: The Case of the 1980 Irpinia Earthquake Re-Examined   总被引：3，自引：0，他引：3  

Janusz Wasowski  Vincenzo Pierri  Pierpaolo Pierri  Domenico Capolongo 《Surveys in Geophysics》2002,23(6):563-593

Most of the documented slope failures triggered by the 1980 Irpinia earthquake (M_s 6.9) occurred in the upper Sele valley epicentral area (southern Italy). The early investigations revealed some puzzling characteristics of the slope failure distribution, i.e., (i) the higher landslide concentration on the valley slopes located farther away from the earthquake fault; (ii) the predominance of re-activations over first-time movements. The analyses of factors controlling the landslide concentrations indicates that the differences in hydrological setting and in slope were the two main causal factors whereas the seismic shaking, according to the radiation pattern modelling, could have been characterised by a relatively low rate of decrease across the valley. The aspect of the slopes did not play a significant role. The differences in groundwater conditions between the western and eastern valley sides were probably enhanced by the earthquake. In addition to the probable pore-water pressure rise, the seismic shaking caused large increases in the flow of springs draining the western aquifer, and this made the adjacent flysch slopes more prone to landsliding. Data from the available literature suggest that the effects of earthquake-induced groundwater release on seismic landslide distribution is especially important for normal-fault events. The Sele valley case also indicates that the slope of the pre-existing landslides is an important factor controlling their susceptibility to seismic re-activations.  相似文献   

试论百色手斧文化由西方扩散的可能性     

吴文祥 《地质科技情报》2002,21(2):23-28

更新世中期是全球气候和环境变化的一个重要时期，当时气候周期转型，全球冰量增加，海平面下降，哺乳动物迁徙或灭绝，这个时代也是直立人地理大扩张和手斧文化扩散的一个重要时期，这些事件在发生时间上的统一性指示它们之间的某种联系，推测更新世中期全球性的气候转变是这次手斧文化扩散的主要驱动力，中国百色盆地发现的手斧可能是西方阿舍科技术向东渗透或扩散的结果。  相似文献   

Magnetic and electric field observations during the 2000 activity of Miyake-jima volcano, Central Japan   总被引：1，自引：0，他引：1  

Yoichi Sasai  Makoto UyeshimaJacques Zlotnicki  Hisashi UtadaTsuneomi Kagiyama  Takeshi HashimotoYuji Takahashi 《Earth and Planetary Science Letters》2002,203(2):769-777

Magnetic and electric field variations associated with the 2000 eruption of Miyake-jima volcano are summarized. For about 1 week prior to the July 8 phreatic explosion, significant changes in the total intensity were observed at a few stations, which indicated uprising of a demagnetized area from a depth of 2 km towards the summit: this non-magnetic source can be regarded as a vacant space itself. Electric and magnetic field variations were observed simultaneously associated with the tilt-step event, which was the abrupt (∼50 s) inflation at a few km depth within the volcano followed by gradual recovery (∼several hours). The electric field is ascribed to the electrokinetic effect most probably due to forced injection of fluids from the source, while the magnetic field to the piezomagnetic effect due to increased pressure. Large magnetic variations amounting to a few tens of nT were observed at several stations since July 8, and they turned almost flat after the August 18 largest eruption. Magnetic changes are explained mostly by the vanishing of magnetic mass in the summit and additionally by the thermal demagnetization at a rather shallow depth. A large increase in the self-potential by 130 mV was also observed near the summit caldera associated with the August 18 eruption, which suggests that the hydrothermal circulation system sustained within the volcano for the past more than 10 years was destroyed by this eruption.  相似文献   

内蒙古伊勒门盆地砂岩型铀矿成矿水文地质条件初析   总被引：3，自引：0，他引：3  

魏云杰  孙泽轩 《四川地质学报》2002,22(2):98-100

简要介绍了伊勒门盆地地下水赋存条件与分布情况，论述了该盆地的构造－水文地质特征，着重阐明区内地下水补给、径流、排泄等水动力条件以及水文地球化学特征，总结了有利的铀矿成矿水文地质条件。  相似文献   

茂县城区后山龙洞沟泥石流形成条件及防治方法探讨     

罗永忠  郝红兵 《四川地质学报》2002,22(2):101-105

茂县后山龙洞沟为老的泥石流沟，流域面积为14．63km^2，主沟长9．9km，有三条支沟，主、支沟沟床比降大，在暴雨季节曾多次发生大规模泥石流。根据其泥石流形成特征，采取以拦挡、排导等工程措施为主，结合植树造林、预警预报、工程管理等措施为辅的综合防治方案。  相似文献   

Imagining difference: the experiences of 'transnational' Indian IT professionals in Germany     

Louise Meijering  Bettina van Hoven 《Area》2003,35(2):174-182

In this paper we explore the motivations to migrate and the migration experiences of 22 Indian IT professionals in Germany. When studying skilled migration, Germany is an interesting case as it struggled with waves of extreme right activities whilst trying to attract IT professionals from outside the European Union at the same time. In this context, we are interested in the conflicts that the migrants may experience as a result of their desire or obligation to move, their specific cultural baggage and the way in which they encounter the different sides of German society.  相似文献   

Mineral magnetic record of Holocene environmental changes in Sägistalsee, Switzerland     

A.M. Hirt  L. Lanci  K. Koinig 《Journal of Paleolimnology》2003,30(3):321-331

The Holocene magnetic signature due to environmental change has been investigated in sediments from Sägistalsee, a small alpine lake in the Bernese Alps, Switzerland. The environmental signal in the mineral magnetic parameters of the sediments was compared with palynological and geochemical data. The types of magnetic minerals and their grain size reflect changes in the lake catchment, vegetation, and degree of erosional input. The concentration of the magnetic minerals, as expressed by isothermal and anhysteretic remanent magnetizations also reflect changes in vegetation, but may also be related to redox conditions during sedimentation. Climate influence on the mineral magnetic record has been recognized and interpreted as a consequence of the production of an authigenic mineral with particularly uniform magnetic properties during warmer stages and the influx of heterogeneous detrital magnetic mineral during cooler stages and under increased human activity.  相似文献   

亚热带山地民族文化与自然环境和谐发展实证研究--以云南省元阳县哈尼族梯田文化景观为例   总被引：21，自引：2，他引：21  

角媛梅  肖笃宁  程国栋 《山地学报》2002,20(3):266-271

一定的自然环境孕育了与之相适应的民族文化，而民族文化又对自然环境具有改造作用。民族文化与自然环境的相互适应是文化与环境持续存在的原因。本文通过深入到处云南南部亚热带山地地区的元阳县哈尼族地区的调查，提出和分析了哈尼文化与自然环境相互适应的结果一哈尼梯田文化景观的特征，并探讨了哈尼文化与自然环境两者梯田景观的关系，证实了哈尼梯田文化景观是哈尼文化与自然环境协调发展的结果，具有重要的理论和实际意义。  相似文献   

基于关系数据库的CA模型扩展和时空模拟实验研究     

罗平  杜清运  何素芳  黄耀丽 《地理与地理信息科学》2002,18(3):8-12

具备时空计算特征的元胞自动机 (CA)模型与地理信息系统 (GIS)集成在地理过程模拟方面具有很大的优势 ,但标准CA在邻居规则等方面的严格定义制约了CA对真实世界的模拟能力。在分析了元胞空间关系和元胞邻居描述的基础上 ,该文提出元胞邻居不仅存在几何空间上的邻接形式 ,还存在空间上不邻接但属性上相关的邻居形式。传统思路的模型扩展很难完全解决CA的局限性 ,基于关系数据库来定义和选择元胞邻居是一种有益的理论尝试。以时空为载体的文化革新扩散系统具有多空间扩散形式和遗传特征 ,相对于标准CA基于关系数据库的CA扩展模型可以更真实地对其进行时空模拟 ,笔者以服装传播为典型案例做实验研究 ,取得了比较满意的实验结果。认为基于关系数据库的CA扩展模型比较适用于具有多空间扩散形式的复杂系统的过程模拟。  相似文献   

Maintaining family values? Cleansing the streets of sex advertising   总被引：2，自引：0，他引：2  

Phil Hubbard 《Area》2002,34(4):353-360

The Criminal Justice and Police Act 2001 makes it an offence to place an advertisement for sex work in public telephone boxes. In this paper, I discuss the background to this Act, exploring the reasons why the presence of sex advertising in a public space has provoked a classic piece of 'moral panic' legislation. Highlighting the role of this new legislation in policing the boundaries between public and private space, the paper thus engages with key debates in social and cultural geography concerning the maintenance of socio–spatial order.  相似文献