邢东矿井构造特征及应力应变场分析

邢东矿井位于太行山隆起带与华北沉陷带的过渡带,通过区域构造应力-应变场分析,本区先后经历了由挤压-拉张的变形过程,变形强度由弱到强。海西期构造应力影响较弱,印支期-中燕山期构造应力作用较为强烈,形成了大量的挤压结构面和压缩构造．燕山晚期-喜山期是构造形成的最终阶段,以拉张伸展变形为主,现今的多数正断层的断裂结构面仍保存有先期的挤压结构面特征。区内构造以断裂构造为主要形式,断层组合形式多样,这些构造形成期次不同,北西向断裂对北东向断裂具有限制作用。     

山西天池煤矿构造特征及其形成机制

基于天池煤矿地质勘探资料,结合区域构造背景研究了矿井地质构造特征及形成机制。天池煤矿构造属简单构造,地层总体呈走向北东、倾向北西的单斜构造,矿井内褶皱发育程度较低,断层以正断层为主,其次为低角度逆掩断层。陷落柱分布较为杂乱,成群出现,常见于褶皱轴部。自三叠纪末期开始一直受到区域构造活动的控制作用,印支期受SN向的挤压,形成了一些近EW向的构造;燕山期经历两期NWW--SEE向挤压使井田内地层及煤层主体呈NE走向;喜山早期的NE—SW向挤压,导致NE向断层的性质发生转变;上新世开始表现为区域上的伸展作用。     

Long-term seismic noise investigations on Shikotan Island: First results

In 2003–2004, long-term seismic noise observations were launched on Shikotan Island (Lesser Kuril Range) based on the “Shikotan” dormant regional seismic station. The geological and geophysical data on the registration area are reported. Information about the equipment and its technical specifications is given. The precursors to the strongest local earthquakesthat occurred in the Shikotan Island region in January 2005–March 2007 are identified.     

震灾保险研究中的软科学问题

震灾保险研究融会着自然科学与社会科学的紧密结合和相互渗透,基于这一认识,本文联系震灾保险的社会属性,分析并指出这一险种的非强制性质;保护应用的权益与责任;对社会不规范投保行为的制约;正确理解“与国际惯例接轨”、地震系统的协作模式、政府部门的政策导向等等带有根本性的问题,以启示人们把握研究的大方向,从而加快我国该项研究的实用化进程。     

研究“源兆”的若干问题及途径分析

从位场理论的观点讨论了场和源的概念,建议将“场兆”改称为构造前兆,将“源兆”称为震源前兆。文中还分析了震源体与各种前兆观测方法探测的深度,并根据地磁与重力观测方法不同的物理基础和地质基础,指出震磁效应对于研究震源前兆的特殊意义,文中还介绍了１９７６唐山地震观测到震源前兆的部分实际地磁资料。     

The Epi－continental arc of Southeast China and relevant earthquakes

ＴｈｅＥｐｉ┐ｃｏｎｔｉｎｅｎｔａｌａｒｃｏｆＳｏｕｔｈｅａｓｔＣｈｉｎａａｎｄｒｅｌｅｖａｎｔｅａｒｔｈｑｕａｋｅｓＪＩＡ－ＷＥＩＸＵ（徐嘉炜）ＤｅｐａｒｔｍｅｎｔｏｆＲｅｓｏｕｒｃｅａｎｄＥｎｖｉｒｏｎｍｅｎｔａｌＳｃｉｅｎｃｅｓ,ＨｅｆｅｉＵ...     

北京及邻区微震活动的初步分析

通过对北京遥测地震台网近年来记录到的北京及邻区地震的震中分布,地震活动频度及能量释放强度的分析,得到本区地震活动在时间分布上具有“聚堆性”。在年发震频度,地震强度和能释放方面均具有双峰值特征,并且具有较好的一致性和同步性,在空间分布上具有条带特征,且形成北东～南西和北西～南东的两条相互交汇的条带。又通过统计分析得到本区发震概率最大的时间段是每年的１０月前后,而地震主要发生在北西～南东带上。     

ELECTROCHEMICAL MEASUREMENT OF STEEL CORROSION IN SEABOTTOM SEDIMENT WITH “MD” METHOD

The tbough one year cormsion potential and polarisation resistanoc for 3 kinds of stals in seabottomedment of Liaodong Bay were measured with the “MD” method.The measurements wiIl have some thoretical and pndital talues. The thooretical valoc lies in thatthe reoorded changing process of the practital corrosion case can be basis for indoor discussion andeectrochemical on the corrosion practical value lies in that the obtained datu canbe basis for designing and controlling elatrochemical protation syttems. In fact, it is very difficult tomeasure in situ the cornosion parnders of steeIs in sea sediment.     

Energy balance of simple elastodynamic sources

Complete relations are derived for energy and energy flux of elastic waves generated by an isotropic and double-couple source in a perfectly elastic, homogeneous, isotropic, and unbounded medium. In the energy balance of elastodynamic sources near-field waves play an essential role, transforming static energy into wave energy, andvice versa. For explosive and dislocation sources, the sources surface radiates a positive wave energy that is partially distributed to the medium transforming into static energy. For implosive and antidislocation sources, the source surface generates elastic waves, but it does not necessarily imply that it also radiates a positive wave energy. The energy transported by waves can originate in gradual transformation of the static-to-wave energy during propagation of waves through a stressed medium.On leave from Geophysical Institute, Czech Academy of Sciences, Boní II/1401, 41 31, Praha 4 Czech Republic     

Earthquake rupture complexity due to dynamic nucleation and interaction of subsidiary faults

We numerically study the dynamic interaction of propagating cracks. It is assumed that propagating cracks can nucleate and drive subsidiary cracks because of shear strain enhancement near the propagating crack tips. The critical strain fracture criterion is assumed in the analysis. Intense interaction is expected to occur among the cracks. All the cracks are assumed to be parallel and antiplane strain deformation is assumed in the computation.In the interaction of two non-coplanar cracks, a strain shadow is formed in the neighborhood of each crack because of the strain release by the introduction of the crack. The growth of each crack is accelerated when the propagating tips of each crack are outside of the strain shadow of the other crack. In general, the crack tips enter the strain shadow, and the crack tips decelerate. The calculation shows that only one of the two cracks can continue to grow, and the other's growth is decelerated and arrested. If we can assume that the suite of cracks interact in a pairwise manner only, then this may suggest that only a limited number of cracks can continue to grow during the final stage of the rupture process. Hence the crack interaction causes complexity in dynamic earthquake faulting. The concepts of barrier and asperity have been employed by many researchers for the interpretation of complex seismic wave data. However, the physical realities of such concepts are obscure. Our calculations show that dynamic crack interactions can produce barriers and asperities in some cases; the crack tip deceleration or arrest due to the interactions among non-coplanar cracks can be interpreted as being due to a barrier. The dynamic coalescence among the coplanar cracks can be regarded as an asperity.Umeda found a localized area that strongly radiates high-frequency seismic waves in the epicentral areas of some large shallow earthquakes. He defined this as an earthquake bright spot. Our analysis implies that only a limited number of cracks continue to grow when many interactive cracks nucleate, and that all other cracks stop extending soon after nucleation. Hence, if the nucleation and termination of several cracks occur in a localized area, it will be observed seismologically as an earthquake bright spot. This is because it is theoretically known that the sudden termination of crack growth and dynamic crack coalescence efficiently emits high-frequency elastic waves.