Crustal attenuation characteristics of S-waves beneath the Eastern Tohoku region,Japan          下载免费PDF全文

Muhammad Adeel Arshad 《地震科学（英文版）》2016,29(5):259-269

An inversion method was applied to crustal earthquakes dataset to find S-wave attenuation characteristics beneath the Eastern Tohoku region of Japan.Accelerograms from 85 shallow crustal earthquakes up to25 km depth and magnitude range between 3.5 and 5.5were analyzed to estimate the seismic quality factor Q_s. A homogeneous attenuation model Q_s for the wave propagation path was evaluated from spectral amplitudes, at 24 different frequencies between 0.5 and 20 Hz by using generalized inversion technique. To do this, non-parametric attenuation functions were calculated to observe spectral amplitude decay with hypocentral distance. Then, these functions were parameterized to estimate Q_s. It was found that in Eastern Tohoku region, the Q_s frequency dependence can be approximated with the function 33 f~(1.22) within a frequency range between 0.5 and 20 Hz. However,the frequency dependence of Q_s in the frequency range between 0.5 and 6 Hz is best approximated by Q_s(f) = 36f~(0.94) showing relatively weaker frequency dependence as compared to the relation Q_s(f) = 6 f~(2.09) for the frequency range between 6 and 15 Hz. These results could be used to estimate source and site parameters for seismic hazard assessment in the region.  相似文献   

震前蒙城地震台地脉动噪声的特征     

张明明  曾宪军  杨骏  应允翔  陈俊  汪继林 《防灾减灾学报》2016,(1):51-58

对本台数字化地震观测以来记录到的典型地震,运用数字地震信号处理方法,测算每个抽选地震震前一分钟地脉动信号在时间域和频率域的特征数据,通过频谱分析法,获得了震前地脉动噪声频谱的差异性。初步研究了典型地震震前地脉动频谱变化的特征和规律,共归纳了18类震前地脉动噪声类型,按照无震平静分钟值脉动频谱特征类比典型地震震前分钟值频谱的异样变化,发现正常与异常的地脉动噪声特征,最主要的还是受震级强度和地理位置的影响较大。临震前地脉动分钟值频谱特征异常,可用于震前脉动前兆异常变化跟踪,从而利用地脉动频谱的特征参量监测地震孕育过程,为地震中长期及短临预报提供依据。  相似文献   

用同相叠加方法识别定点形变数据中的降雨影响     

杨学慧  常玉巧  李燕玲  应骁睿  杨海鹏  崔庆谷 《大地测量与地球动力学》2016,36(10):936-940

分别以昆明台、云龙台为例,用数据同相位叠加的方法分别对形变数据中的典型图像及其对应时段的降雨数据进行叠加,以判断典型图像是否与降雨有关。结果表明,昆明台形变观测中多次出现的同步转折为降雨影响;而云龙台的转折现象则与降雨无关,其来源及属性需要进一步研究。  相似文献   

光通信用IOGHzCMOS八分频器设计     

邓文娟  雷鑑铭 《华东地质学院学报》2009,32(3):289-292

在比较反转触发器（TFF）的各种结构基础上,采用一种单时钟信号控制,实现高速分频的电路结构,设计实现了用于光通信中时钟数据恢复电路的八分频器。该八分频器使用动态负载,输出两路互补信号,采用SMIC0．18um1P6MCMOS工艺,使用Cadence公司的Spectre仿真器进行模拟验证,实验结果证明,在电源电压为1．8V的情况下,该八分频器的工作速度10GHz、功耗仅为4．705mW。  相似文献   

The Enya mounds: a lost mound-drift competition     

D. Van Rooij  V. A. I. Huvenne  D. Blamart  J.-P. Henriet  A. Wheeler  H. de Haas 《International Journal of Earth Sciences》2009,98(4):849-863

The genesis and evolution of cold-water coral banks along the Northeastern Atlantic margin is known to be influenced by several factors, among which the palaeotopography and nature of the coral settling surface, the presence of bottom currents and sediment supply. In this paper, a case study is presented of the Enya mound cluster, located in the southernmost tip of the Belgica mound province, west of Ireland. Below this mound cluster, seismic stratigraphy revealed a yet unmapped local unconformity RD1b, being part of a composite erosion event (RD1). As such, from the Late Miocene to Late Pliocene, at least two erosional events have incised the margin, ending with the final RD1a “moundbase” unconformity, acting as a base for the Enya mounds. During the Quaternary the mounds became outgrown and were covered by a mounded contourite drift. In addition, they are closely associated with a cluster of seabed pockmarks. The bottom current regime which became active since the Middle Pleistocene has certainly influenced the fate of this mound cluster. The occurrence of the pockmarks seems to be related to relatively recent fluid migration processes, however leaving an open question if any previous seepage phases were involved in the growth or initiation of the coral banks.  相似文献   

甘肃地区近震震级的量规函数研究   总被引：5，自引：4，他引：1  

陈继锋  尹欣欣  董宗明  姚海东  蒲举 《中国地震》2013,29(3):327-334

采用甘肃测震台网“十五”宽频带数字地震记录资料,选取自2009 年1 月～ 2012 年12 月所记录的13086 次地震事件,通过震级残差统计方法计算了各台站单台震级与台网平均震级的偏差、平均偏差和标准偏差,分析了震级偏差频次分布和定量统计,修正了ML量规函数,得到了代表甘肃地区的地方性均匀震级量规函数。  相似文献   

基于择优的块体模型解算南北地震带中南段主要断层滑动速率   总被引：1，自引：1，他引：0  

闫伟  武艳强  牛安福  李晓帆  张凌空  吉平 《中国地震》2013,29(1):81-90

利用1999 ～2007期GPS速度场数据,通过块体模型择优得到了南北地震带中南段主要块体边界带变形的适用模型,并给出了块体边界主要断层的滑动速率.结果表明,龙门山断裂带宝兴-汶川段张压速率较小,为0.5 ～ 1.8mm·a-1;汶川-茂县压性相对显著,速率达1.8～3.8mm·a-1;鲜水河断裂带张压及走滑速率存在一定的空间差异性特征,即炉霍以北张性滑动速率(8.1mm·a-1)比左旋走滑速率(4.8mm·a-1)大,炉霍-道孚段张压速率与走滑速率基本相同,道孚-康定段呈现出左旋走滑速率减小、张性速率增大的变化趋势,康定-石棉段表现出较明显的左旋走滑性质;小江断裂带走滑速率明显大于张压速率;红河断裂带空间分段性较为明显,北西段滑动量较小,但存在一定的张压分量(景东段速率4.7 mm·a-1),南东段(个旧以西)以走滑为主(速率4.5mm·a-1).  相似文献   

吉林测震台网数字台站台基噪声功率谱分析     

张宇  康建红  张晨侠  郑国栋  陈聪  丁广 《地震地磁观测与研究》2013,34(3)

介绍吉林测震台网数字台站仪器配置,对台网31个测震台站台基噪声功率谱进行计算,得出各地震台台基的地动噪声的均方根值、观测动态范围、地噪声功率谱,并将计算地动噪声功率谱作为吉林地震台网资料分析处理的一项日常工作进行.  相似文献   

山东诸城农居抗震性能分析对比     

冀东普  郭惠民 《高原地震》2013,(3):58-62

通过对山东诸城民居现状进行调查,发现其抗震性能较差。对山东农村民居在抗震设防中存在的突出问题进行了分析并提出了应对方案。  相似文献   

地震尺度下碳酸盐岩储层的岩石物理建模方法(英文)   总被引：3，自引：3，他引：0  

李景叶  陈小宏 《应用地球物理》2013,10(1):1-13

碳酸盐岩油藏的强非均质性以及孔隙结构的复杂性,使得作为连接油藏参数与地震参数重要桥梁的岩石物理模型,以及作为油藏预测和定量表征最有效工具的流体替换成为岩石物理建模的难点与重点。在碳酸盐岩储层复杂孔隙结构与地震尺度下碳酸盐岩储层非均质性分析基础上,研究采用岩石网格化方法,将地震尺度下非均质碳酸盐岩储层岩石划分为具有独立岩石参数的均质岩石子体,根据岩石孔隙成因与结构特征采用不同岩石物理模型分步计算岩石子块干岩石弹性模量,并根据不同孔隙连通性进行流体替换,计算饱和不同流体岩石弹性模量。基于计算的岩石子块弹性模量,采用Hashin-Shtrikman-Walpole弹性边界计算理论方法实现地震尺度下碳酸盐岩储层弹性参数计算。通过对含有不同类型孔隙组合碳酸盐岩储层模型的弹性模量进行计算与分析,明确不同孔隙对岩石弹性参数的影响特征,模拟分析结果与实际资料认识一致。  相似文献