A Preliminary Discussion on the Mechanism of Abnormal Intensity Zones of the M5.1 Wen''an Earthquake in 2006     

Zhang Suling  Zhao Jingyi  Lin Jie 《中国地震研究》2009,23(4):448-457

An earthquake measuring 5.1 on the Richter scale struck Wen'an county,Hebei Province on July 4,2006. No casualties have been reported,with only slight damage. The disaster level of this event is the slightest on the M4.9～5.1 events record tally since the CCDSN (China Center of Digital Seismic Network) was built in 1999. The epicenter intensity of this earthquake was low,while in areas like Beijing,which is 100km far away,abnormal high intensity zones appeared. This article discusses the reasons behind this abnormal phenomenon,with the diagrams of intensity isolines drawn by the intense seismic stations and networks in the capital circle area as references,as well as the seismogenic mechanism in the source,the seismic histories,the geological structures and the ray pathways of seismic waves in areas within 150km around the epicenter. It was concluded that the special dynamic and geological situations were the main causes for the lower intensity degree and slight damage in the epicenter area,but higher intensity in the surrounding areas.  相似文献   

2011年1月安徽安庆Ms4.8地震震源区三维速度结构与发震构造讨论     

陈安国  倪红玉  刘东旺  沈小七  刘泽民  郑海刚 《中国地震研究》2012,26(2):259-267

The Anqing MS4.8 earthquake occurred on January 19, 2011, with the epicenter lying in the foreland deformation belt along the Yangtze River of the lower Yangtze block. After the earthquake, the field work team surveyed and collected building damage data, calculating and obtaining more accurate intensity distributions. The focal mechanism of the main shock was calculated tentatively using digital seismic wave data from provincial digital seismic networks using the FOCMEC program and the first motions of P, SV and SH waves with their amplitude ratios. Using the location results of the main shock and aftershocks by the Anhui seismic network, combining the three-dimensional crust velocity structure imaging results of the focal region by seismic tomography, and referring on intensity distribution of the elliptic major axis’ predominant direction, we conclude by comprehensive analysis that the NE-trending Susong-Zongyang fault is possibly the causative fault of the Anqing earthquake.  相似文献   

汶川M_S8.0地震兰州烈度速报强震动记录与初步分析          下载免费PDF全文

刘旭宙  张元生  周民都  闵祥仪 《地震工程学报》2010,32(4):376-380

2008年汶川MS8.0地震有感地区范围大于1 000km。甘肃省十五期间在兰州市架设了50个强震台站用于实现市区范围内的强震动烈度速报,在本次地震中大多数台站都记录到了相应的强震动记录,其中最大单道加速度峰值记录为40.4cm/s2。本文展示了43个兰州烈度速报台站记录到的共129道本次地震强震动记录信息,并初步分析了兰州市加速度峰值分布和加速度峰值与土层厚度的对应情况。  相似文献   

Stability analysis of Lagrangian points of geo-synchronous satellite including the resistive force and earth’s equatorial ellipticity     

《New Astronomy》2022

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绿色勘查在土地质量地球化学调查中的探索与实践          下载免费PDF全文

万方  于林松  胡尊芳  康桂玲  陈莉  李浩嵩 《山东国土资源》2022,38(12)

土地质量调查作为地球化学勘查的一种技术手段，具有覆盖面积广、样品类型多等特点。在传统土地质量调查基础上开展绿色勘查具有重要的意义。依据土地质量地球化学调查方法技术体系，提出了土地质量地球化学绿色勘查工作思路，依托胶东典型丘陵区“山东省莱阳北部地区土地质量地球化学调查与评价”项目，系统总结了土地质量地球化学调查中生态环境敏感区识别、点位布设及优化、样品采集及回填、样品加工、采样工具优化等方面的绿色勘查经验和做法，开展了绿色勘查示范，为推广绿色勘查在地球化学勘查工作方面提供了借鉴依据。  相似文献   

水声定位系统中迭代适应点分层的声线修正算法          下载免费PDF全文

陈嘉兴  赵晓旭  董怡靖  丁路  刘志华 《海洋科学》2023,47(4):155-164

水声定位系统中, 声线弯曲是造成定位误差大的主要原因, 本文针对该问题提出了一种迭代适应点分层(IAPL)的声线修正算法, 将声速剖面筛选分层修正声线。首先搭建水声定位模型, 通过拟合目标海域的监测数据, 得到声速高次函数; 其次探究声线弯曲时目标位置与掠射角的关联性, 由此构造出声线插值函数并求解路径参数; 最后提出划分原则, 精简声速剖面分层。仿真结果表明, 所提算法定位误差较低, 分层精简率均维持在48.04%的水平, 使计算量平均下降可达50.27%, 能够最大程度保留声速剖面的原始特征, 减少分层数量, 提高计算效率。  相似文献   

水准网中起算点的选用方法探讨     

徐万祥  柴本红  于松 《山东国土资源》2009,25(10):50-52

水准网平差中起算点质量好坏不仅影响平差精度,而且如果采用不好的点位,直接影响成果的使用,带来严重后果。该文以青州市水准网的布设为例,分析讨论了起算点对水准网精度的影响,提出了根据较差中误差大小选用起算点的方法,阐述了该方法的步骤,达到的效果,以及水准网布设方法等。  相似文献   

控制点数量与DEM分辨率对海岸带遥感影像正射校正精度影响分析   总被引：1，自引：0，他引：1       下载免费PDF全文

刘善伟  张杰  马毅 《海洋科学》2009,33(4):9-13

在保证海岸带区域控制点均匀分布的基础上，对3景SPOT-5影像分别使用1：5万DEM和SRTM90m数据，开展6个、9个、12个控制点的影像正射校正。结果表明：在海岸带区域，基于传感器物理模型的1景SPOT-5影像正射校正，6个控制点即可保证较高的精度，控制点数量的增多对精度的提高并不显著；1：5万DEM比SRTM90m数据对影像的正射校正精度略高，但并不明显，在缺少1：5万DEM时，用SRTM90m数据代替亦能满足908课题的精度要求，进一步验证了SRTM90m数据在高分辨率遥感影像正射校正中的可用性。  相似文献   

The influence of third order terms on basins of convergence in the Hénon–Heiles type system     

《New Astronomy》2022

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Preliminary report of the September 5, 2022 MS 6.8 Luding earthquake,Sichuan, China     

《地震研究进展（英文）》2023,3(1):100184

The 2022 M_S 6.8 Luding earthquake is the strongest earthquake in Sichuan Province, Western China, since the 2017 M_S 7.0 Jiuzhaigou earthquake. It occurred on the Moxi fault in the southeastern segment of the Xianshuihe fault, a tectonically active and mountainous region with severe secondary earthquake disasters. To better understand the seismogenic mechanism and provide scientific support for future hazard mitigation, we summarize the preliminary results of the Luding earthquake, including seismotectonic background, seismicity and mainshock source characteristics and aftershock properties, and direct and secondary damage associated with the mainshock. The peak ground displacements in the NS and EW directions observed by the nearest GNSS station SCCM are ～35 mm and ～55 mm, respectively, resulting in the maximum coseismic dislocation of 20 mm along the NWW direction, which is consistent with the sinistral slip on the Xianshuihe fault. Back-projection of teleseismic P waves suggest that the mainshock rupture propagated toward south-southeast. The seismic intensity of the mainshock estimated from the back-projection results indicates a Mercalli scale of VIII or above near the ruptured area, consistent with the results from instrumental measurements and field surveys. Numerous aftershocks were reported, with the largest being M_S 4.5. Aftershock locations (up to September 18, 2022) exhibit 3 clusters spanning an area of 100 km long and 30 km wide. The magnitude and rate of aftershocks decreased as expected, and the depths became shallower with time. The mainshock and two aftershocks show left-lateral strike-slip focal mechanisms. For the aftershock sequence, the b-value from the Gutenberg-Richter frequency-magnitude relationship, h-value, and p-value for Omori’s law for aftershock decay are 0.81, 1.4, and 1.21, respectively, indicating that this is a typical mainshock-aftershock sequence. The low b-value implies high background stress in the hypocenter region. Analysis from remote sensing satellite images and UAV data shows that the distribution of earthquake-triggered landslides was consistent with the aftershock area. Numerous small-size landslides with limited volumes were revealed, which damaged or buried the roads and severely hindered the rescue process.  相似文献