赤峰中心地震台地面与井下地震观测系统监测能力对比分析     

郭延杰  于章棣  齐彬彬  屈楠  范东海  黄瑞滨  刘继伟 《地震地磁观测与研究》2020,41(4):100-104

为分析总结地面与井下地震观测系统的特点，以赤峰中心地震台地面与井下观测系统为研究对象，在噪声分析、噪声功率谱分析、地震监测能力和观测动态范围等方面进行分析。结果表明，2套观测系统的RMS均可达到Ⅱ级环境地噪声水平，井下观测系统噪声小于地面观测系统。对2套观测系统的功率谱密度、有效动态范围的对比均表明，井下观测系统的动态范围比地面观测系统超出约10%，因此，井下观测系统地震监测能力优于地面观测系统，井下观测系统能更有效地记录观测数据。  相似文献   

考虑地形起伏和障碍体破裂的汶川地震强地面运动数值模拟   总被引：2，自引：1，他引：1       下载免费PDF全文

赵由佳  张国宏  单新建  尹昊  屈春燕 《地球物理学报》2018,61(5):1853-1862

2008年5月12日四川汶川地区发生M_W7.9地震，震中位置103.4°E，31.06°N.这次地震造成了以汶川、映秀为中心及其周边地域建筑物的严重破坏和人员的重大伤亡，且因为高山等地形复杂区域抢险救灾的艰巨性，为及时救援造成很大干扰.为更好理解地形因素对于强地面数值模拟结果的影响，建立了包含地形起伏影响及去除地形影响的两类模型.同时，依据震源破裂过程运动学反演结果，建立了包含障碍体破裂过程的震源滑动模型，实现断层分段、空间倾角以及滑移角的动态设定.基于动力学的地震动模拟方法，通过对地震波传播过程的数值计算和后处理分析，模拟由地震激发的区域强地面运动过程.结果显示：（1）强震动台站的断层距对地形效应具有放大或抑制作用，距离断层破裂带越近，地形效应越明显，反之，距离越远，则地形效应越微弱；（2）因为地形高差与障碍体的影响，地震造成的峰值可能出现在震中区域之外；（3）考虑地形影响模型的地表峰值速度（PGV）区域位于汶川与北川附近；而未考虑地形影响模型的PGV区域位于灌县—江油断层的后半段，处清平、安县附近；对汶川地震近实时强地面运动波场的模拟、峰值图谱的圈定及未来大地震强地面运动特征的预测都有重要指示意义.  相似文献   

USE OF SEISMIC WAVEFORMS AND INSAR DATA FOR DETERMINATION OF THE SEISMOTECTONICS OF THE MAINLING M_S6.9 EARTHQUAKE ON NOV.18, 2017     

LIU Yun-hua  SHAN Xin-jian  ZHANG Ying-feng  ZHAO De-zheng  QU Chun-yan 《地震地质》2018,40(6):1254-1275

On November 18, 2017, a M_S6.9 earthquake struck Mainling County, Tibet, with a depth of 10km. The earthquake occurred at the eastern Himalaya syntaxis. The Namche Barwan moved northward relative to the Himalayan terrane and was subducted deeply beneath the Lhasa terrane, forming the eastern syntaxis after the collision of the Indian plate and Asian plates. Firstly, this paper uses the far and near field broadband seismic waveform for joint inversion (CAPJoint method)of the earthquake focal mechanism. Two groups of nodal planes are obtained after 1000 times Bootstrap test. The strike, dip and rake of the best solution are calculated to be 302°, 76° and 84° (the nodal plane Ⅰ)and 138°, 27° and 104° (the nodal plane Ⅱ), respectively. This event was captured by interferometric synthetic aperture radar (InSAR)measurements from the Sentinel-1A radar satellite, which provide the opportunity to determine the fault plane, as well as the co-seismic slip distribution, and assess the seismic hazards. The overall trend of the deformation field revealed by InSAR is consistent with the GPS displacement field released by the Gan Wei-Jun's team. Geodesy (InSAR and GPS)observation of the earthquake deformation field shows the northeastern side of the epicenter uplifting and the southwestern side sinking. According to geodetic measurements and the thrust characteristics of fault deformation field, we speculate that the nodal plane Ⅰ is the true rupture plane. Secondly, based on the focal mechanism, we use InSAR data as the constraint to invert for the fine slip distribution on the fault plane. Our best model suggests that the seismogenic fault is a NW-SE striking thrust fault with a high angle. Combined with the slip distribution and aftershocks, we suggest that the earthquake is a high-angle thrust event, which is caused by the NE-dipping thrust beneath the Namche Barwa syntaxis subducted deeply beneath the Lhasa terrane.  相似文献   

中国海洋无脊椎动物分类学与系统演化研究进展与展望     

李新正  寇琦  王金宝  甘志彬  杨梅  龚琳  隋吉星  马林  曲寒雪  初雁凌  曾宥维  王伟娜  张祺  董栋 《海洋科学》2020,44(7):26-70

综述了我国海域无脊椎动物的分类学和系统演化研究的历史和概况，以及我国分类系统学工作者在海洋无脊椎动物分类学、区系与动物地理学、系统发育与分子系统学领域的主要工作，重点介绍了中国科学院海洋研究所的海洋无脊椎动物分类学工作。涉及类群包括原生动物、海绵动物、刺胞动物、线虫、多毛类环节动物、星虫、螠虫、软体动物、节肢动物、苔藓动物、毛颚动物、棘皮动物、半索动物等主要的无脊椎动物门类。涉及海域以我国管辖海域，特别是中国近海为主，也涉及了西太平洋、西南印度洋等深海环境的无脊椎动物类群的分类学报道。本文总结过去，展望未来，对于在我国在海洋无脊椎动物分类与系统演化研究领域成就基础上，发现薄弱环节，研讨今后本学科的发展方向，填补研究空白，赶超本领域国际前沿，都有重要借鉴意义。  相似文献   

前墙结构对OWC气室捕能效果影响的数值研究     

曲铭  于定勇  王世林  康骁 《海岸工程》2020,39(2):111-118

基于不可压缩黏性流体理论和VOF(Volume of Fluid)方法建立了二维数值波浪水槽模型,将模拟波形与波浪理论值进行对比,分析了模型可靠性,并利用该模型研究了5种不同前墙结构OWC气室在不同波高、周期时的出气口速度和气室内空气压强。基于模拟结果,从波能-动能转换效率和气室内空气压强角度分析了前墙结构对OWC气室的捕能效果的影响。结果表明:对于传统的直立型OWC气室,采用合适的前墙结构可有效提高OWC气室的捕能效果;相比三角截面(20D型,30D型)和矩形(Y型)截面前墙,采用椭圆截面(20TY型,30TY型)的前墙结构的捕能效果更优,且在周期较大(1.6和1.8 s)时其作用更显著,其波能-动能转换率相对Y型前墙结构气室平均提升37%;5种前墙结构不同的气室中,20TY型和30TY型前墙结构气室的捕能效果最优。  相似文献   

论渔业法之未取得或违反船网工具指标造船违法行为的法律责任          下载免费PDF全文

曲芮  裴兆斌  郭云峰 《海洋开发与管理》2020,37(3):12-15

船舶是渔业生产、水上运输的重要工具，我国对渔业船舶借助船网工具控制指标管理模式达到对渔船数量和功率数控制的“双控”管理，但实践中碍于很多因素还存在未取得或违反船网工具指标造船的现象，这一行为对水域交通安全、渔业生产安全、渔业资源保护3个方面都存在安全隐患。文章主要梳理现行法律法规对这一行为的规定并简要分析其法律责任，建议在处罚幅度中增加处罚下限。  相似文献   

珠江三角洲地区活动断裂探查方法浅析          下载免费PDF全文

黄孝波  孙社良  屈尚侠 《山东国土资源》2019,35(9)

活动断裂是指晚第四纪以来活动过的断裂,它威胁到人类生命财产安全。该文通过文献调研,结合珠江三角洲基底断裂探查研究项目的实际工作,介绍了地面地质调查、浅层地震、断层气测量、钻探及连孔剖面、断裂物质测年、历史地震分析等活动断裂探查方法,以及这些方法的优缺点,并指出了目前活动断裂探查存在的一些问题,提出了建议。  相似文献   

ENVIRONMENTAL RESPONSE OF THE PERMIAN VOLCANISM IN LUCAOGOU FORMATION IN JIMSAR SAG,JUNGGAR BASIN,NORTHWEST CHINA          下载免费PDF全文

QU Chang-sheng  QIU Long-wei  YANG Yong-qiang  YU Kuan-hong  TANG Li-li  WAN Min 《地震地质》2019,41(3):789-802

The lithological features, the types of organic matter and its occurrence and carbon and oxygen isotopic value were clarified by combining core observation, thin slice authentication, X ray diffraction analysis, kerogen type identification and carbon and oxygen isotope analysis. The characteristic of strata, the distribution of volcanoes of Junggar Basin were also taken into consideration. A comprehensive analysis was conducted to evaluate environmental response of volcanism in Lucaogou formation in Jimsar sag. The results show that rocks is a mixed sedimentation of effusive rock and carbonate rocks, volcanic materials is widely developed in Lucaogou formation and origins from the edge of sag or distant source volcano activity. Organic matter is predominantly unstructural algae and asphaltene. The carbon isotopic value of carbonates ranges between 6.8‰ and 9.7‰ with an average of 8.3‰, featured in high positive excursions, while oxygen isotopic value varies from -11.9‰ to -4.3‰ with an average of -6.2‰. During the period of volcanic activity, the volcanic material released high amounts of nutrient to the lake basin, which is beneficial to the algae and other organic organisms. In the poor oxygen and calm water environments, the organic matter is distributed in the laminar algal and the carbon isotope value is high positive drift. During the intermittent period of volcanic activity, the lake level decreased and the lake bottom water changed to the oxygen-enriched environments. The organic matter is locally enriched or dispersed in local layers, and the carbon isotope values decreased slightly. The frequent volcanic activity promoted the organism boom, which lead carbon isotope value to have high positive characteristics and change trends.  相似文献   

COSEISMIC DISPLACEMENT FIELD OF THE WENCHUAN EARTHQUAKE DERIVED FROM STRONG MOTION RECORDS AND APPLICATION IN SLIP INVERSION          下载免费PDF全文

LIU Xiao-dong  SHAN Xin-jian  ZHANG Ying-feng  YIN Hao  QU Chun-yan 《地震地质》2019,41(4):1027-1041

The development of high-rate GNSS seismology and seismic observation methods has provided technical support for acquiring the near-field real-time displacement time series during earthquake. But in practice, the limited number of GNSS continuous stations hardly meets the requirement of near-field quasi-real-time coseismic displacement observation, while the macroseismographs could be an important complement. Compared with high-rate GNSS, macroseismograph has better sensitivity, higher resolution(100~200Hz)and larger dynamic range, and the most importantly, lower cost. However, baseline drift exists in strong-motion data, which limits its widespread use. This paper aims to prove the feasibility and reliability of strong motion data in acquiring seismic displacement sequences, as a supplement to high-rate GNSS. In this study, we have analyzed the strong-motion data of Wenchuan M_S8.0 earthquake in Longmenshan fault zone, based on the automatic scheme for empirical baseline correction proposed by Wang et al., which fits the uncorrected displacement by polynomial to obtain the fitting parameters, and then the baseline correction is completed in the velocity sequence. Through correction processing and quadratic integration, the static coseismic displacement field and displacement time series are obtained. Comparison of the displacement time series from the strong motions with the result of high-rate GPS shows a good coincidence. We have worked out the coseismic displacement field in the large area of Wenchuan earthquake using GPS data and strong motion data. The coseismic displacement fields calculated from GPS and strong motions are consistent with each other in terms of magnitude, direction and distribution patterns. High-precision coseismic deformation can provide better data constraint for fault slip inversion. To verify the influence of strong-motion data on slip distribution in Wenchuan earthquake, we used strong motion, GPS and InSAR data to estimate the stress drop, moment magnitude and coseismic slip model, and our results agreed with those of the previous studies. In addition, the inversion results of different data are different and complementary to some extent. The use of strong-motion data supplements the slip of the fault in the 180km segment and the 270~300km segment, thus making the inversion results of fault slip more comprehensive. From this result, we can draw the following conclusions:1)Based on the robust baseline correction method, the use of strong motion data, as an important complement to high-rate GNSS, can obtain reliable surface displacement after the earthquake. 2)The strong motion data provide an effective method to study the coseismic displacement sequence, the surface rupture process and quick seismogenic parameters acquisition. 3)The combination of multiple data can significantly improve the data coverage and give play to the advantages of different data. Therefore, it is suggested to combine multiple data(GPS, strong motion, InSAR, etc.)for joint inversion to improve the stability of fault slip model.  相似文献   

基于向量式有限元的黏滞阻尼减震结构抗竖向连续倒塌动力反应分析          下载免费PDF全文

曲激婷  宋全宝 《地震工程学报》2019,41(6):1432-1439

向量式有限元是以向量力学为基础的一种新的结构分析方法,在处理结构大变形等复杂行为时具有较大的优势。基于向量式有限元理论建立了黏滞阻尼单元,对附加黏滞阻尼器的平面钢框架结构进行了抗竖向连续倒塌动力分析,结合拆除构件法,采用MATLAB编制可以考虑初始变形的瞬时卸载法程序,实现结构在构件拆除前的静力分析和构件拆除后动力分析的全过程统一。研究了阻尼器布置位置和参数在结构抗竖向连续倒塌中的性能需求,以失效点竖向位移时程曲线、梁端转角、动力放大系数和结构塑性铰分布为参考指标,对比分析布置阻尼器前后钢框架结构的抗连续倒塌能力。结果表明向量式有限元是一种研究结构竖向连续倒塌动力响应的有效方法,合理布置阻尼器能够有效控制剩余结构的变形和振动,降低构件内力,减少塑性铰个数,较大地提高结构的抗竖向连续倒塌能力。  相似文献