2001年上半年全球地震活动

2001年上半年，全球发生MW≥6．5地震22次，其中浅源地震19次，中源地震2次，深源地震1次；发生MW≥7．0地震8次，最大震级达MW8．4。6月23日秘鲁沿海发生了MW8．4地震，这是36年来矩震级最大的地震。上半年地震灾害严重，1月26日发生在印度的MW7．6地震使2万多人丧生。     

2001年下半年全球地震活动

2001年下半年，全球发生MW≥6．5地震15次，其中浅源地震13次，中源地震2次；发生MW≥7.0地震6次。下半年MW≥7．0地震的地震矩释放是1976年以来的中等水平。2001年11月14日发生在中国新疆－青海交界的MW7．8地震，是下半年全球矩震级最大的地震。     

ZC油田活性剂驱效果评价研究

通过实验物理模拟，确定HABS磺酸盐型阴离子表面活性剂作为化学驱三次采油的驱油剂，在ZC油田进行了为期一年的矿场先导性试验并做出效果评价，确证HABS表面活性剂驱在ZC油田起到了稳油控水、增产挖潜的作用，有明显的经济效益。     

2003年新疆地震灾害损失述评

在列出2003年中国4．7级以上地震目录的基础上，结合地震灾害评估和科学考察资料，总结出2003年新疆地震灾害的特点。     

塔里木河流域2003年"四源一干"河川径流及输水运行分析

2003年塔里木河四条源流出山口天然径流量258.21×108 m3,偏多12.8%,属偏丰水年.阿拉尔站以上的三条源流(阿克苏河、叶尔羌河、和田河)出山口天然径流量为221.19×108 m3,偏多14.0%,属偏丰水年;开都河孔雀河为37.02×108 m3,偏多6.0%,属平略偏丰水年.四条源流入塔里木河总水量为47.66×108 m3,占出山口天然径流总量的18.5%.阿拉尔站以上三条源流入塔里木河水量为44.08×108 m3,占三条源流出山口天然径流总量的19.9%,叶尔羌河是惟一无水输入塔里木河的源流.2003年塔里木河干流上游段耗水量20.51×108 m3,是干流最大的耗水区段,中游段耗水量16.89×108 m3,下游段耗水量11.16×108 m3.上、中游耗水量在减少,下游耗水量在增加.从2003年3月3日至7月11日第5次应急输水历时132 d,从博斯腾湖调水入塔河干流水量3.58×108 m3,而塔河干流到达恰拉水量7.58×108 m3,干流来水量继2002年后再次超过了博斯腾湖调水量.可以确定,2002年塔里木河向下游输水属于由博斯腾湖调水为主转为干流为主的转折年份,但是2003年干流向下游输水的比例更高.2003年大西海子水库向最下游下泄水量为3.455×108 m3,首次打通了145 km的老塔里木河,采取其文阔尔河和老塔里木河双河道输水,水再次流到塔里木河尾闾--台特玛湖,加上车尔臣河水的汇入,年内在台特玛湖区最大形成了约200 km2的水面.长期确保向塔河下游输水以干流来水为主,加大对塔河的综合治理,特别要加大对干流上游段和主要源流区的综合治理.     

1994年4－6月的全球地震动态

１９９４年第二季度，全球地震活动仍维持中等水平。爪哇岛以南爪哇海沟内发生以７．２级地震为主的强震序列。南美洲接连发生深震，６月９日玻利维亚北部发生大深震，有感范围极大。大洋岛弧带地震频数占全球半数以上，本季度最大地震也发生在此。亚欧带继续维持中等水平的活动，亚欧带西段地震活动的发展需要继续监视和跟踪。     

2-D seismic tomographic and ray tracing modelling of the crustal structure across the Sudetes Mountains basing on SUDETES 2003 experiment data

The seismic data obtained during SUDETES 2003 experiment are analysed, and detailed crustal structure for profiles S02, S03 and S06 is presented using three different 2-D techniques: (1) “smooth” tomography of refracted waves travel times, (2) ray tracing of reflected and refracted waves, and (3) joint velocity and depth of reflector tomographic inversion. In spite of different interpretation techniques used, the models of the crustal structure show common characteristic features. The low velocity (V_p < 4 km/s) sedimentary layer was documented in the northeastern part of the study area. The topmost basement has in general a velocity of 5.8–6.0 km/s, and velocities at ca. 20 km depth are 6.15–6.25 km/s. The strong reflecting boundaries were found at 20–23 and 25–28 km depth with a velocity contrast about 0.4 km/s, and the highest velocities in the lowermost crust are 6.8–7.2 km/s. In general, the crust of the Bohemian Massif is slightly thicker (33–35 km) than in the northern part of the area. Velocities beneath Moho are relatively low, of 7.95 km/s. On the basis of well recorded reflected waves, mantle reflectors were discovered in the depth interval ca. 40–70 km. Apart of new results for the geology and tectonics of the area, some conclusion could be made about different techniques used. In the 2-D case the “clasical” ray tracing method with using all correlated phases gives the most adequate model of the structure, because of full, manual control of the model creation. The “smooth” first arrival travel times tomography, although very fast, is not satisfactory enough to describe the complex structure. So, the best candidate in 3-D case seems to be travel time tomography for both refracted and reflected waves in multi-layers models.     

Imaging the heterogeneous source area of the 2003 M6.4 northern Miyagi earthquake, NE Japan, by double-difference tomography

A shallow M6.4 inland earthquake occurred on 26 July 2003 in the northern part of Miyagi Prefecture, northeastern Japan. This earthquake was a typical inland thrust earthquake, a type that is common in NE Japan. We obtained a detailed seismic velocity structure in the focal area of this earthquake by the double-difference tomography method. Arrival-time data came from temporary seismic stations deployed above the mainshock fault plane. Both the P-wave and S-wave velocities in the hanging wall were lower than those in the footwall. Aftershocks were aligned along a zone where the seismic velocity changes rapidly. This is consistent with the interpretation that the 2003 northern Miyagi earthquake occurred along a fault that acted as a normal fault in the Miocene and has been reactivated as a reverse fault under the present compressional stress regime. The large slip area by the main shock rupture (asperity) corresponds to an area with relatively high P- and S-wave velocities. A zone with low V_p/V_s was detected along the aftershock area. One of the possible causes of this low-V_p/V_s zone is the existence of high-aspect-ratio pores that contain water. Hypocenters of the main shock, largest foreshock, and largest aftershock are also located within the low-V_p/V_s zone.     

EDM三角高程测量在大型桥梁中的应用

通过对EDM三角高程测量基本原理的分析,确定测量误差的主要来源,并在施测过程中制定相应的质量控制措施,保证EDM三角高程测量满足桥梁工程测量精度要求,并以南京大胜关长江大桥为例进行说明.     

某通讯基站对炸药库雷击风险的影响分析

以移动通讯基站为例，从基站“引雷”作用的角度，通过理论和计算分析，认为基站能使周边环境雷击频率和雷电强度增加，但基站周边建筑物自身受直击雷危害的影响远大于受基站雷击感应的影响，所以基站周边建筑物自身要有完善的防雷装置才能保证其安全。