内蒙古中西部地区中小地震矩震级研究   总被引：1，自引：1，他引：0  

刘芳  张帆  李彬  娜热 《中国地震》2017,33(2):301-310

基于S震相"S窗"内的波形信号识别、品质因子Q(f)和22个台站场地响应,利用2009~2016年3月内蒙古中西部地区地震的波形资料,反演了182次中小地震的震源波谱参数,得到这些小震的零频幅值及其拐角频率,据此计算了这些地震的地震矩M_0、矩震级M_W和应力降Δσ。利用回归分析方法得到了近震震级与矩震级、矩震级与应力降的关系式。分析表明,近震震级与矩震级、矩震级与应力降呈线性关系。可见,将矩震级纳入地震的快报与正式目录中,可以丰富地震观测报告内容,更好地为地震应急和地震科研服务。  相似文献   

基于国普数据的芦山县地震应急基础数据更新及其应用研究     

申源  蔡晓燕  张莹  郭红梅 《震灾防御技术》2017,12(4):893-901

通过研究地理国情普查数据和四川省芦山县地震应急基础数据库的数据类型、数据结构及二者间的关系，完成了地理国情普查数据向芦山县地震应急基础数据的转换与更新；并以芦山地震为例，利用城镇地震应急快速评估系统验证了更新后数据的可靠性。  相似文献   

宿迁地震台地震监测能力分析   总被引：1，自引：1，他引：0  

张荣杉  冯武  彭澎  贾少罡 《地震地磁观测与研究》2017,38(4):199-202

根据宿迁地震台地震计和数采参数、台站背景噪声等数据,结合历史地震观测数据,运用统计学计算方法,计算宿迁地震台地震监测能力。结果认为:宿迁地震台短周期台基背景噪声较大,微小地震监测能力较弱,但基本可以监测到M_L 2.0地方震,也可监测到150 km范围内周边城市M_L 2.5地震。  相似文献   

川滇地块南部主要断裂现今形变特征及危险性分析   总被引：1，自引：1，他引：0  

徐东卓  李胜虎  周海涛  王阅兵  王世进 《震灾防御技术》2017,12(3):539-546

本文利用川滇地块南部30余年的跨断层观测资料，计算了跨断层场地的三维活动量，分析了区域内断裂的现今形变特征以及川滇地块南部的运动方式，认为部分断裂现今表现出异常活动的现象，川滇地块南部整体表现出以水平顺时针旋转为主的运动学特征，并对该区域中短期地震危险性做出了初步推测。  相似文献   

Shake table investigation on the seismic performance of hospital equipment supported on wheels/casters          下载免费PDF全文

Farzad Nikfar  Dimitrios Konstantinidis 《地震工程与结构动力学》2017,46(2):243-266

This paper presents an experimental investigation on the seismic response of medical equipment supported on wheels and/or casters. Two pieces of equipment were tested: a large ultrasound machine and a cart carrying smaller medical equipment. In the first phase, the resistance of the wheels and casters of the equipment was characterized through a controlled‐displacement procedure on the shake table. In the second phase, an extensive shake table test program was carried out to investigate the seismic response of the equipment. The input signals for the shake table tests included floor motions of a four‐story steel braced‐frame hospital designed to satisfy seismic requirements of a site in the Los Angeles area. The results of 96 shake table tests reported in this study include the seismic performance of the equipment under both unlocked and locked conditions, located on various floor levels of the building. It was observed that engaging the casters' locking mechanism does not necessarily decrease the relative displacement. The displacement response was sensitive to the excitation intensity and the orientation of the equipment with respect to the input excitation. Based on the experimental observations, appropriate structural engineering demand parameters associated with the relative displacement and relative velocity demands of the equipment are proposed and used to develop conditional probability curves. Finally, in an effort to extend the results of this experimental study to similar equipment on wheels/casters, the performance of a simple numerical model in predicting the peak seismic demands is evaluated. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Preparing for the unprecedented — Towards quantitative oil risk assessment in the Arctic marine areas     

Maisa Nevalainen  Inari Helle  Jarno Vanhatalo 《Marine pollution bulletin》2017,114(1):90-101

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滇西南普洱强震群地区地壳形变的数值模拟     

李铁明  白玉柱  邵德晟 《中国地震》2017,33(2):203-218

滇西南普洱一带地质构造复杂,中-强地震成群活动特征明显,地壳的形变特征与形变机制引起了地学界的广泛关注和深入研究。在参考、借鉴以往研究成果的基础上,本文构建了普洱一带包含活动断裂的二维板有限元模型,以GPS测量得到的块体年运动量作为模型区域的边界约束,模拟计算获得了普洱地区的构造形变空间分布,以NEE、NNW 2个方向、从数值模拟角度对普洱地区的水平形变特征和区域地壳垂直形变场进行了分析和探讨。结果表明:在青藏高原东南缘扩展、高原物质重力滑塌型南东向移动的动力学背景下,研究区内NEE向断裂的活动带动牵引NNW向断裂共轭运动,隆升性质的垂直形变场与60年的大区域水准测量结果相吻合,沿NNW向形变场的分布无规律,应是区域应力累积和震后调整双重作用的结果。沿NEE向形变场呈现了较明显的西部大于东部的分布图像,特别是西北部高值区对应了2014年景谷6.6级强震,最后对研究区的区域动力学问题进行了初步探讨。  相似文献   

Macroinvertebrate community structure and feeding interactions along a pollution gradient in Gilgel Gibe watershed,Ethiopia: Implications for biomonitoring     

《Limnologica》2017

Feeding interactions among functional feeding groups (FFGs) of macroinvertebrates are robust indicators of aquatic ecosystem interactions. They provide information regarding organic matter processing, habitat condition and trophic dynamics. In tropical rivers with pronounced wet and dry seasons, macroinvertebrate based ecological monitoring tools are explicitly focused on metrics and indices, while ignoring interactions of FFGs. Therefore, the objective of this study was to investigate the functional feeding type metrics, diversity indices and feeding interactions among FFGs of macroinvertebrates along the water pollution gradient in Gilgel Gibe watershed, Ethiopia. Water quality parameters and macroinvertebrate community attributes were assessed for samples collected from upstream sites (15 sites), urban-impacted stretches (12 sites) and wetland-affected river zones (7 sites) of the watershed during the rainy (July) and dry (February) seasons. To understand the effect of pollution on the feeding interactions, stable carbon and nitrogen isotopes were analyzed. Macroinvertebrate-based diversity indices and functional feeding type metric showed deterioration of ecological integrity at the urban-impacted sites and substantial recovery in the wetland-affected downstream sites. Omnivorous feeding behavior of macroinvertebrates was noted for the upstream sites, whereas clear trophic guilds of FFGs were suggested for the wetland-affected river zones by the stable isotope results. The results of pollution gradient analysis and feeding interactions among FFGs revealed that the urban-impacted sites showed weaker interactions when compared to upstream and wetland influenced sites. This affirms the potential importance of feeding interactions among FFGs of macroinvertebrates in water quality monitoring.  相似文献   

积雪在El Niño影响东亚夏季气候异常中的作用          下载免费PDF全文

王妍凤  孙旭光  杨修群 《地球物理学报》2017,60(9):3325-3337

本文利用1948-2010年Global Land Data Assimilation System（GLDAS）NOAH陆面模式资料、GPCC月平均降水资料和NCAR/NCEP全球月平均再分析资料，采用滤波、距平合成和线性相关等方法，分析了El Niño成熟位相冬季欧亚大陆积雪异常的分布特征，研究了关键区积雪融化对后期春、夏季土壤湿度、土壤温度以及大气环流与降水的影响，揭示了El Niño事件通过关键区积雪储存其强迫信号并影响东亚夏季气候异常的机制和过程.主要结论如下：El Niño成熟阶段冬季伊朗高原、巴尔喀什湖东北部和青藏高原南麓区域是雪深异常的三个关键区，这些区域的雪深、雪融和土壤湿度有明显的正相关；这三个关键区雪深异常通过春季融雪将冬季El Niño信号传递给春、夏季局地土壤湿度，通过减少感热通量和增加潜热通量对大气环流产生影响；春末夏初伊朗高原土壤湿度异常对东亚夏季气候异常的影响最大，其引起的降水异常与El Niño次年夏季降水异常分布基本一致，春夏季青藏高原南麓和巴尔喀什湖附近土壤湿度也都明显增加，均会对中国华北降水增加有显著正贡献.总之，在利用El Niño事件研究和预测东亚夏季气候异常时，还应考虑关键区雪深异常对El Niño信号的存储和调制作用.  相似文献   

The Fluxes and Behaviour of Plumes Inferred from Measurements of Coherent Structures within Images of the Bulk Flow     

H.C. Burridge  J.L. Partridge  P.F. Linden 《大气与海洋》2016,54(4):403-417

This paper describes how measurements of the movement of identifiable features at the edge of a turbulent plume can be interpreted to determine the properties of the mean flow and consequently, using plume theory, can be used to make estimates of the fluxes of volume (mass), momentum, and buoyancy in a plume. This means that video recordings of smoke rising from a chimney or buoyant material from a source on the sea bed can be used to make accurate estimates of the source conditions for the plume. At best we can estimate the volume flux and buoyancy flux to within about 5% and 15% of the actual values, respectively. Although this is restricted to the case of a plume rising in a stationary and unstratified environment, we show that the results may be of practical use in other more complex situations. In addition, we demonstrate that large-scale (turbulent) coherent structures at the plume edge form on a scale approximately 40% of the local (mean) plume half-width and travel at almost 60% of the average local (mean) velocity in the plume.  相似文献