春季大风、降雪和沙尘暴天气的信息数字化方法的分析

Using informational digital diagrams, we analyzed the snow event that occurred on Feb 26, 2006 and the sandstorm on Apr 11, 2006 in Xi＇an. Results indicate that, under similar weather circumstances, different events evidently exhibit unique vertical structure features. Informational digital diagrams provide a method for transitional weather prediction, a problem for present extrapolative analysis system.     

Study on the Phenomenon of Geomagnetic Low-value Displacement before Moderately Strong Earthquakes in Gansu

This paper analyzes the distribution characteristics of geomagnetic low-value displacement in Gansu and its adjacent areas from 1995 to 2003 on the basis of the data of the daily amplitude minimum value time of the geomagnetic vertical component. It is shown that in addition to the changing rules of geomagnetic low-value displacement itself, there is a better correlation between geomagnetic low-value displacement and the occurrence of moderately strong earthquakes. There appeared to be geomagnetic low-value displacement before the moderately strong earthquakes in Gansu in the 9 years from 1995 to 2003. This result indicates that geomagnetic low-value displacement is of instructive significance for earthquake prediction to some extents.     

断层破裂方式对银川盆地强地面运动的影响

银川盆地是受断层控制的断陷性盆地,边缘和内部发育了多条断裂带,特别是其内部晚更新世-全新世活动的银川隐伏断层可能对银川市的建设规划和抗震设防影响较大.为了研究银川隐伏断层活动对银川盆地强地面运动特征的影响,本文以银川隐伏活动断层作为目标断层,模拟了断层发生Mw6.5特征地震时,在单侧破裂和双侧破裂两种方式下,银川盆地的强地面运动分布特征.分析结果表明在两种破裂方式下,盆地内强地面运动表现出不同形态的地震条带状分布特征和上盘效应;同时受到银川盆地边缘断裂"西陡东缓"构造特征的影响,地表强地震动分布和断层附近观测点的时程也呈现出独特的盆地边界反射作用.在单侧破裂和双侧破裂两种模式下,近场强地面运动集中区总体上呈现北强南弱的现象,银川市及附近的芦花台等地区是强地面运动分布的主要区域.     

地震动随机函数模型研究(Ⅰ)——模型建立

基于随机过程的随机函数解释,发展了一种随机地震动模型.模型包括两个部分,分别是基于理论物理关系的Fourier幅值谱模型和基于经验关系的Fourier相位谱模型.基于拟加速度谱概念建立的幅值谱模型能够反映强震记录的幅值特性,而Fourier相位谱模型则利用累积相位谱的单值连续特性,以线性多项式与三角级数组合的形式给出.模拟记录与实测记录对比结果显示两者不仅在波形结构上相似性良好,而且反应谱层次亦吻合良好.     

河北省地震局遥测台网日志统一管理系统

日志在遥测台网工作中的意义重大,为了更好地管理遥测台网的日志,研制了遥测台网日志统一管理系统。本系统将对目前台网产生的日志进行统一管理,为工作人员记录日志和利用日志检查工作提供了方便。     

地震活动图像分析预测汶川8．0级地震的回顾与思考

本文回顾了2008年5月12日四川省汶川8．0级特大地震前中长期及年度趋势预测过程。作者根据地震活动图像特征作出了较好预测,明确指出四川石棉-冕宁和汶川-松潘一带,2008年前后,可能发生7级以上地震。但带短期预测特点的2008年度大震危险性,作者没有作出确切的预测。本文思考了相关的经验教训并对改进分析预报工作提出了构想。     

Real-time seismology for the 05/12/2008 Wenchuan earthquake of China: A retrospective view

The devastating 05/12/2008 Wenchuan earthquake (M_w7.9) in Sichuan Province of China showed very few precursory phenomena and occurred on a fault system once assigned to be of moderate long term seismic risk. Given the existing coverage of seismograph stations in Sichuan Province, real-time seismology could have been effective in avoiding some earthquake damage and helping post-earthquake emergency response. In a retrospective view, we demonstrated that the epicenter can be located with 20 km accuracy using just two broadband stations with three-component, which takes only about 10 s after the onset of the earthquake. Initial magnitude is estimated to be M7 with the Tc measurement over first 4 seconds of P waves. Better magnitude estimate can be obtained within 2 min by modeling Pnl waves for stations about 500 km away where the S waveforms are clipped. The rupture area is well revealed by teleseismically-recorded >M5 early aftershocks within two hours after the mainshock. Within a few hours, teleseismic body waves were inverted to derive a more detailed rupture process and the finite fault model can be readily used to calculate ground motions, thus providing vital information for rescue efforts in the case where no real-time strong motion records are available. Supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX2-YW-116-1) and National Key Technology Research and Development Program of China (Grant No. 2006BAC03B00)     

Evidence of multistage late Quaternary strong earthquakes on typical segments of Longmenshan Active Fault Zone in Sichuan,China

Investigation of offset landforms and trench excavation are important means to acquire the evidence of multistage activities of active faults. Here we present the result of fault trough investigation in Beichuan County and the Pingtong Town of Pingwu County along the Longmenshan Central Fault Belt, as well as the result from trench excavation at the platform foreslope in Hanwang Town of Mianzhu County on the Longmenshan Front Range Fault Belt. These results show that at least three fault activity events, in...     

北川县城汶川地震震害特征及其成因探讨

根据笔者在汶川大地震板震区北川县城现场考察的第一手资料,分析了2008年5月12日汶川8．0级大地震后北川县城的震害特征,论述了北川县城地震后建筑物、生命线工程的破坏以及次生地质灾害;并对造成各类震害的原因进行了初步的探讨。最后,在总结震害特征及其成因的基础上,提出了当前应加强研究的相关课题,旨在为今后的工程抗震设防和研究提供参考。     

辽宁省强震台网的地震应急效果初探

本文介绍了辽宁省强震台网在2008年11月14日析木MS4．3级地震中的应急反应情况,同时进行了反思。并针对辽宁强震台网的可持续发展谈了一些个人看法。