工程地震钻孔柱状图的微机绘图系统

根据工程地震工作的需要,建立了适用于工程地震的岩土柱状图形库,编制了一套工程地震钻孔柱状图的微机绘图系统.该系统可直接生成集各岩土层参数、标贯值、岩土柱状图及剪切波速直方图等内容于一体的工程地震钻孔柱状图.所形成的图件规范、美观,内容完整、精确,大大提高了工作效率.     

鸭绿江断裂西南段地震活动特征分析

依据鸭绿江断裂历史地震和近期地震的活动状况,分析了鸭绿江断裂西南段的地震活动特征,并对未来地震活动趋势进行了判断。     

山西洪洞ML5.0地震前测震学异常指标分析

对山西洪洞2003年ML5．0地震进行了分析，发现震前1a左右，在临汾盆地周边地区相继出现断层总面积、η值、A(b)值、D值、5值、YH值等地震活动性指标异常，这些指标异常反映了5．0级地震前地震活动呈现增强的特征。根据非线性理论中的尺度依赖性原理提出一种对特定范围的中强地震进行检验性预测的方法。     

西菲律宾海盆的构造沉积特征及对海盆演化的指示——来自地球物理大断面的证据

菲律宾海发育了全球最典型的沟弧盆体系,新老俯冲系统众多,是研究大洋板块扩张过程的理想场所。本文主要利用2015年中科院海洋所在西菲律宾海采集的1400km地球物理大断面,并结合最新的重力数据,对比、分析了西菲律宾海内部古扩张中心(中央海盆裂谷)和残留弧(九州-帕劳海脊)的沉积地貌和地壳结构特征。研究表明:(1)中央海盆裂谷内部发育远洋沉积为主的沉积物,沉积层序分布不均,局部盆地内沉积物厚度可达300m。九州-帕劳海脊附近发育与火山碎屑物源有关的厚层沉积物;(2)以129°30′E处的转换断层为界,裂谷东西部洋壳结构分别体现"慢速"和"快速"扩张特征,东部洋壳岩浆供应较少,厚度较小,断裂较为发育,其附近可能发生水岩作用;西部洋壳岩浆供应较多,厚度较大,结构相对均一;盆地西部的小规模地幔柱可能控制了裂谷东西部不同洋壳结构的发育;(3)九州-帕劳海脊内的角度不整合面代表岛弧裂解事件,张裂与挤压构造共同发育反映了裂解过程的复杂性。     

Behavior of the Rayleigh-Taylor mode in a dusty plasma with rotational and shear flows

The stability of a dusty plasma with sheared rotational flows is investigated. Using the fluid model together with the Bayly nonmodal approach, the inhomogeneous partial differential equations governing short-wavelength perturbations at the center of a rotational flow field or vortex structure are obtained. The effects of flow eccentricity, strength of the flow shear, as well as concentration of dust grains on the stability of the perturbations are investigated numerically. It is found that flow shear can cause secondary Rayleigh-Taylor instability of a rotational flow.     

视应力方法在震群性质判定中的应用研究

利用视应力方法研究了1999～2004年辽宁地区发生的岫岩、 海城、 营口震群性质, 结果显示: 前震序列与其它震群视应力曲线变化形态是完全不同的, 视应力的大小能较好地反映出震源区应力场的大小。 利用视应力数值变化探讨区域震群性质, 与地震活动性参数判定震群性质的方法, 更能反映出每个震群应力场的变化过程, 在原方法不能准确确定震群性质的情况下, 根据应力场的变化过程可以进一步判定震群的性质。 文中还探讨了视应力与震级之间的关系。     

台阵地震学方法及在中国IMS台阵的应用研究

中国的地震台阵建设与发展比国外晚了几十年.目前国内地震台阵正在不断地建设,而缺少的就是台阵技术,如能够把已有的台阵技术应用到我国的台阵中,就可以让台阵发挥它们应有的价值.作者根据国外的参考文献主要讨论了台阵地震学的主要技术方法并把这些方法应用到中国的IMS台阵,并给出了应用实例.结果表明,地震台阵使我们对地下结构的研究更加精细,使我们对微弱信号的识别更加轻松.如果我国现有台阵都能应用台阵地震学技术将对我国地震学和地球物理学的发展起到很大的推动作用.     

煤矿地应力异常层析成像方法的研究

地震层析成像技术是一种有效的物探方法.该文采用最小旅行时和SIRT法,对煤田中的地应力异常地震层析成像的方法进行成像研究,具有一定的理论价值和现实意义.     

Particle transport mechanics and induced seismic noise in steep flume experiments with accelerometer-embedded tracers

Recent advances in fluvial seismology have provided solid observational and theoretical evidence that near-river seismic ground motion may be used to monitor and quantify coarse sediment transport. However, inversions of sediment transport rates from seismic observations have not been fully tested against independent measurements, and thus have unknown but potentially large uncertainties. In the present study, we provide the first robust test of existing theory by conducting dedicated sediment transport experiments in a flume laboratory under fully turbulent and rough flow conditions. We monitor grain-scale physics with the use of ‘smart rocks’ that consist of accelerometers embedded into manufactured rocks, and we quantitatively link bedload mechanics and seismic observations under various prescribed flow and sediment transport conditions. From our grain-scale observations, we find that bedload grain hop times are widely distributed, with impacts being on average much more frequent than predicted by existing saltation models. Impact velocities are observed to be a linear function of average downstream cobble velocities, and both velocities show a bed-slope dependency that is not represented in existing saltation models. Incorporating these effects in an improved bedload-induced seismic noise model allows sediment flux to be inverted from seismic noise within a factor of two uncertainty. This result holds over nearly two orders of magnitude of prescribed sediment fluxes with different sediment sizes and channel-bed slopes, and particle–particle collisions observed at the highest investigated rates are found to have negligible effect on the generated seismic power. These results support the applicability of the seismic-inversion framework to mountain rivers, although further experiments remain to be conducted at sediment transport near transport capacity. © 2018 John Wiley & Sons, Ltd.