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41.
岩石破坏前的短临应变前兆研究   总被引:5,自引:1,他引:5  
采用新型应变仪观测岩样在破坏孕育过程中岩样表面测点的应变变化,结果除了长趋势变化,破坏前几秒的特征变化外,在破坏前百分之几秒至十分之几秒还有突变和拢动等特征变化。  相似文献   
42.
云南腾冲火山区上部地壳三维地震速度层析成像   总被引:22,自引:3,他引:22  
根据1999年腾冲火山区人工地震探测资料,用层析成像方法反演了腾冲火山区上地壳三维P波速度结构.层析成像结果显示出,在腾冲火山区下方的上地壳内存在明显的P波低速区,该低速区在地下7~8km深度,可能与上地壳内的岩浆囊或部分熔融体有关.层析结果还显示出低速区主体在热海地区的东北侧.地表附近的低速区可能是构造破裂发育地区形成了有利于深部热流体上升的通道,因此,在热海形成最活跃的地热显示.   相似文献   
43.
In this paper,the features of medium-term anomalies for strong earthquakes and the criteria for the prediction of such earthquakes are discussed,as well as the feasibility of applying the anomalies of astronomical time-latitude residuals to earthquake prediction and their limitation when applied to imminent-term prediction.The criteria used to identify the anomalies of time-latitude residuals for M≥6.0 earthquakes in Yunnan Province and for M≥7.0 earthquakes around Yunnan are also discussed.The last strong earthquake in the data used for testing passed the whole process of earthquake prediction practice.In addition,some special features of the case in which anomalies appeared but no strong earthquake followed are also discussed.  相似文献   
44.
In this paper,the temporal and spatial variation process of seismicity in areas from Lancang to Tengchong before the 1988 Lancang-Gengma earthquakes(M=7.6,7.2),January 1980 to October 1988,is studied in detail according to the theory that the whole process of earthquake sequence in the time stage of anomalous seismicity before a strong event may be considered as the non-homogeneous Poisson process.The results demonstrate that(1)from April 1985 to April 1988,there existed an obvious difference of seismicity in spatial distribution in the whole region; to the north of Lancang,there occurred two seismic quiescent belts:one is 210 km long for M≥3.5 events and anotheris 160 km long for M≥3.0 events; therefore,this may be classified into four sub-regions from south to north,that is,the south region,the mid-region,the mid'-region,and the north region.(2)Before the mainshocks,there existed anomalous seismic quiescence for as Song as 42 months in the mid-region(M≥3.5)and 32.5 months in the mid'-region(M≥3.0)  相似文献   
45.
藏北双湖地区上三叠统肖茶卡群的重新厘定及其地质意义   总被引:1,自引:5,他引:1  
在双湖地区肖茶卡一带上三叠统肖茶卡群中发现2套砾岩,根据岩石组合、生物化石和界面特征,以2套砾岩为标志层。将原肖茶卡群分解为3个组级岩石地层单位,由下至上分别为肖切堡组、角木茶卡组和日干配错组。从岩石地层、生物地层和层序地层方面阐述了3个组级地层单位的特征和划分的意义。  相似文献   
46.
I.HydrogeographicalCharacteristicsTheLancangMekongRiveroriginatesfromasmallglacierof0.4km2inareaatanelevationof5167minLasaigongmaMountain(alsocalledZhaicuoMountain)atnorthernfootofTanggulaMountainRangewithinZaduoCounty,YushuTibetanAutonomousPrefecture,Qing…  相似文献   
47.
Integrated geophysical interpretation is a method of combinating different geophysics prospecting methods based on different physical properties of accumulation. As different geophysical methods own different interpretations and varying detection accuracies, the key issue becomes how to integrate the results of several geophysical methods to corrently carry out a comprehensive explanation. Based on different geophysical results, the authors proposed an integrated geophysical explanation method and successfully applied it in practical engineering problems.  相似文献   
48.
Phanerozoic strata are distributed in several north-south trending zones in the central part of the Changning-Menglian Belt. Four types of Devonian to Triassic stratigraphic successions can be identified: (1) elastics with limestone lenses in the mid-section, changing up-section into alternations of fine elastics and cherts; (2) elastics with chert intercalations and limestone lenses, and topped by Permian basic volcanics; (3) elastics-basic volcanics-carbonates-clastics; and (4) limestones, dolomitic limestones-dark gray thin-bedded limestones, argillaceous limestones, mudstones and siliceous mudstones. Devonian to Triassic cherts occur in different horizons and different zones from east to west. These cherts are usually transitional to their neighboring elastics. There is no continuous Devonian to Middle Triassic chert sequence in the central zone of the Changning-Menglian Belt as Liu et al. (1991,1993) reported. Volcanics and the overlying carbonates described by some workers as "seamount" sequences  相似文献   
49.
国家间的竞争集中表现为前瞻性技术领域的竞争,占领技术制高点成为各国国家发展的基本取向。本文结合地震观测现状和现代信息网络技术、自动化控制技术的进展,概述了地震观测技术产业化发展的社会需求和科学需求,从国家科技发展战略层次上初步探讨了地震观测技术产业化发展的重要性和必然性。  相似文献   
50.
In this paper, the mobile strong ground motion observation for the destructive earthquake is introduced.Considering the characteristics and its spatial distributions of aftershock, 59 strong ground motion instruments were installed along the Longmenshan fault area, and more than 2 000 records have been accumulated.It shows that it is necessary to per-form the mobile strong ground motion observation after the destructive earthquake, and the precious collected data could be applied for further research.  相似文献   
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