共查询到20条相似文献，搜索用时 46 毫秒
1.
2.
3.
１９９５年３月１９日，新疆和硕县那音克乡发生Ｍｓ５．０级地震。震前，乌鲁木齐地区地下水中溶解气体Ａｒ、ＣＨ４、ＣＯ２、Ｈ２Ｓ等和库尔勒地区的断层气Ｒｎ相继出现明显的异常。异常具有短期临震性质，主要表现为短期趋势升高，临震突跳。 相似文献
4.
5.
6.
对滇西地震预报实验场多年来观测的Ａｒ、Ｎ２、ＣＯ２等断层气体及水氡数据进行了分析，发现与朔望月密切相关的１３．４－１５天及２７．７－３０天周期。它是断层气体的潮汐响应，可称之为“断层气体潮”。这为研究地震异常提供了一项新的对比标准。 相似文献
7.
8.
断层气CO2快速测定法及其在地震研究中的应用 总被引：1，自引：0，他引：1
自八十年代起，国内外地震工作者开始重视断层气的研究。近年来，我国在这方面的研究已获得了很大的进展。有关资料表明，ＣＯ２的释放与断裂活动性关系密切，它也是地震前兆的灵敏组分之一。总之，ＣＯ２是一种对地壳应力反映灵敏的气体地球化学指标，目前已被广泛应用于地震科学研究之中。就测定ＣＯ２的技术方法而言，当前国内餐主要利用气相色谱仪测定。由于气相色谱仪比较昂贵，且操作复杂，需配备具有较高素质的技术人员，所以 相似文献
9.
地壳中的CO2及其释放与地震短临预测 总被引：5，自引：0，他引：5
该文通过对地壳中二氧化碳（ＣＯ２）的分布及其与多震层的关系,以及地壳中ＣＯ２的释放与地震活动关系的分析,探讨了断层带ＣＯ２监测在强震短临预测阶段对时间判定的作用,提出应进一步加强对断层带ＣＯ２释放的监测与研究。 相似文献
10.
总结了对１９９６年２月３日云南丽江７级地震的中短期监视及跟踪预报过程。根据川滇地区地震活动特征和可公度性计算结果,在该次地震前对大形势进行了预测。１９９５年１０月以后,滇西北地区出现了大面积、大幅度、多手段的同步异常,其中以水氡 、水位和ＣＯ２异常为主,沿中甸－南涧的地震区分产为集中。根据上述异常特征及异常分布情况,作在该次地震前２个同大理州政府提出了书面预报意见,认为１９９６年２月底以前在中甸 相似文献
11.
12.
13.
14.
15.
《中国科学:地球科学(英文版)》2014,(3)
正SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research. 相似文献
16.
《国际泥沙研究》2014,(4)
正Director:Shangfu Kuang,China Vice-directors:Chunhong Hu,China Duihu Ning,China Guangquan Liu,China The International Research and Training Center on Erosion and Sedimentation(IRTCES)was jointly set up by the Government of China and UNESCO on July 21,1984.It aims at the promotion of international exchange of knowledge and cooperation in the studies of erosion and 相似文献
17.
Richard D. Hey 《地球表面变化过程与地形》1979,4(1):59-72
Feedback mechanisms, which operate upstream through drawdown and backwater effects and downstream through sediment discharge are responsible for channel evolution. By combining these mechanisms with channel processes it euables a dynamic process-response model to be developed to simulate the initial evolution of straight gravel-bed channels. When erosion commences on a land surface, sediment entrained in the headwater reach by hydraulic action is selectively transported, deposited and reworked. This produces a damped oscillation between degradation and aggradation as the channel and valley respond to spatial and temporal variations in sediment calibre and hydraulic conditions. The initial cut and fill phases are responsible for valley incision and floodplain development while secondary and subsequent activity can produce river terraces. Eventually sediment entrainment in the headwaters declines as slopes are reduced. Subsequent channel evolution is relatively insignificant because it is dependent on local weathering activity producing material that can be transported on declining slopes. Therefore landforms produced during the initial phase of development, when local weathering was non-limiting, dominate the landscape. 相似文献
18.
Based on relocating the Jiujiang-Ruichang earthquake sequence which occurred on November 26, 2005 in Jiangxi Province with the double-difference （DD） algorithm and master event technique, the paper discusses the focal mechanism of the main shock （MsS.7） and the probable seismo-tectonics. The precise relocation results indicate that the average horizontal error is 0.31kin in a EW direction and 0.40kin in a NS direction, and the average depth error is 0.48kin. The focal depths vary from 8kin to 14kin, with the predominant distribution at 10kin - 12kin. The epicenter of the main shock is relocated to be 29.69^oN, 115.74^oE and the focal depth is about 10.Skin. Combining the predominant distribution of the earthquake sequence, the focal mechanism of the main shock and the tectonic conditions of N-E- and NW-strike faults growth in the seismic region, we infer that the main shock of the earthquake sequence was caused by a NW striking buried fault in the Rnichang basin. The nature of seismic faults needs to be further explored. 相似文献
19.
《水文科学杂志》2013,58(6)
Abstract The western reservoirs represent the principal groundwater system in Morocco. Demographic, industrial and agricultural developments during the last decade have markedly altered groundwater quality. The Mamora coastal aquifer system is among the Atlantic systems which are most heavily threatened by pollution. Agricultural and industrial activities, and rapid urban growth contribute to the pollution of the groundwater. Contamination transport is facilitated by a high permeability of the aquifer formations. In order to assess the actual groundwater quality of the Mamora aquifer and to understand the influence of the factors generating the pollution, an extensive multidisciplinary research programme is in progress, with hydrochemistry and microbiology playing essential roles. The present paper concerns the spatial distribution of physico-chemical parameters in the groundwater, subjected to domestic, industrial and agricultural pollution. Fifty-seven samples were analysed for several parameters (Ca2+, Mg2+, Na+, K+, Cl?, SO4 2?, HCO3 ?, NO3 ?, pH, electrical conductivity and temperature). The microbiological analysis of 143 samples reveals the presence of four kinds of indicator bacteria in the groundwater resources: faecal Streptococci, faecal coliform, Escherichia coli and Clostridium. The physico-chemical results and bacteriological monitoring show that the nitrate and bacteria concentrations exceed the maximum admissible levels, notably around pumping stations in the sectors of Sidi Taibi, Sidi Ahmed Taleb and Aïn Sbaâ. Contamination is generated by uncontrolled anthropogenic activities and accentuated by the high intrinsic vulnerability of the aquifer system. Several parameters appeared to exceed admissibility standards. Measures are recommended to prevent groundwater pollution in the region. 相似文献
20.
K.-G. Malle 《洁净——土壤、空气、水》1992,20(4):196-204
Zinc in the Environment. In 1990 the world production of zinc ammounted to 7 Mio. metric tons. The main areas of application were: galvanization, alloys like brass and zinc metal. The content in the earth crust varies between 10–300 ppm zinc with a mean of 70 ppm. Uncontaminated surface waters contain less than 10 mg/m3 zinc. Apart from civilization air contains 1–10 ng zinc per m3. These background concentrations are exceeded by orders of magnitude in zinc deposit areas and where anthropogenic influences predominate. Accumulation can occur in sediments and sewage sludge. Molluscs and Algae also accumulate zinc. Zinc is essential for live. With normal food the zinc supply of man is just sufficient. Bioaccumulation of zinc towards man or chronic oversupply of man is not known. Zinc has no teratogenic or mutagenic effects, a suspicion on a carcinogenic effect proved wrong. In stockbreeding and plant cultivation a minimum supply of zinc is necessary. Plants are relatively less sensitive against higher soil contents of zinc. Considering the toxicological and ecotoxicological effects of zinc in the environment, the critical organismens are marine invertebratae like tubifex, daphnia, gammarus and algae. But normally only a minor part of the total zinc contest is biologically available, depending on salt content and pH of the waters. 相似文献