Quantitative analysis of travel-time curves of seismic events in the Ostrava-Karviná coal mining district

Summary The paper is intended as a contribution to the quantitative analysis of travel-time curves of seismic events recorded in the Ostrava-Karviná District (OKD). The input data represent a set of 2621 seismic events, recorded by the local seismological network of 26 mine stations DSLA and a regional diagnostic polygon consisting of five surface Lennartz stations. All the events were processed automatically in the Operational Seismological Centre of the Czechoslovak Army Mine in Karviná and stored in the seismological data base. The results are presented in the form of graphs of arrival times versus distance for the whole OKD, for two mines and one tectonic block.Travel-time curves of direct P and S waves, as well as of reflected and refracted waves are given. The direct P and S waves propagate well practically throughout the whole region studied, but their apparent velocities of propagation are affected by the properties of the rock medium.As a result of the complicated geological conditions, the recorded wave image is quite complicated. Methods of mathematical modelling, using kinematic and dynamic parameters of seismic waves, will have to be applied to identify the separate wave groups uniquely.     

山东历史地震震害特点之研究

研究了山东省自公元前７０年以来的地震灾害情况，指出山东震灾的主要特点是强度大、频度低、人员伤亡惨重、建筑物破坏严重、地震造成的地面形变类型多种多样。分析了与地震灾害有关的因素，叙述了地震灾害的社会影响。     

罗锅沟大爆破技术

以罗锅沟大爆破为例，介绍了洞室大爆破的施工组织，并着重问述了在进行技术设计时，应注意以下几点：（１）药室的布置及爆破参数的确定；（２）起爆网路的设计；（３）施工设计；（４）安全校核及安全措施。     

Earthquake distribution and volcanism in Kamchatka,Kurile Islands,and Hokkaido Part 3: Southern Kuriles and Hokkaido

Summary The morphology of the Wadati-Benioff zone in the region of Southern Kuriles and Hokkaido, based on the distribution of 4015 earthquake foci, verified the existence of an intermediate depth aseismic gap and its relation to active andesitic volcanism. A paleosubduction zone activated by an intermediate depth collision with the active subduction zone was found and described.

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u Wadati-Benioff amu uu - u a¶rt;, aa a an¶rt;uu 4015 a mu, nm¶rt;ua mau n¶rt; au u amu a¶rt;um au. a a¶rt;a u nuaa a na¶rt;uu, amuuuaa nmu mu amu ¶rt;uu.

     

Motion of particles in turbulent flow: Hyperbolicity,strange attractors and dynamic stochasticity of a system

¶rt;naa, m ma um uu maunuu m am muu ¶rt;uauu um. nua a mau ammama a, n¶rt; mnu ma u u au uu u¶rt;mu.     

东亚大气环流与埃尔尼诺相互影响的一个分析研究

通过对多年地面气压和500hPa高度等资料的统计分析,本文发现在埃尔尼诺现象发生的前一年10—12月和当年1—3月,东亚和西太平洋地区的大气环流都有明显异常,主要特征是东亚有频繁强冷空气活动,且环流异常有由高纬向低纬地区推移的现象.冬季东亚频繁的强冷空气活动使西太平洋副热带高压位置逐渐偏南,造成中、西太平洋信风减弱,可能是埃尔尼诺发生的原因之一。 埃尔尼诺年夏季,由于遥相关机制,东亚及西太平洋中纬地区出现地面气压和高度场的负距平,西太平洋副高位置持续偏南. 基于统计分析结果,本文绘出了一个东亚及西太平洋大气环流与埃尔尼诺相互影响的模型。     

Design and test of an improved scheme for global spectral model with reduced truncation error

An improved scheme of spectral model has been investigated in this paper. Through the introduction of a reference atmosphere, prognostic variables become smoother on the tilled sigma-surface over mountains or a frontal zone, and thus truncation errors are reduced. As a result, the problems about Gibbs waves and negative value of model topography on the sea, which are encountered in the current spectral model in the world, can be solved by the improved scheme. For comparison we have performed the numerical integrations of barotropic and baroclinic Rossby-Haurwitz waves, as well as the prediction of real cases with the improved scheme and the current scheme of spectral model. These results show that the scheme presented in the paper is better than the current scheme of spectral model.