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云南地区数字地震波波速比的区域特征 被引量:11
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作者 李永莉 毛慧玲 +1 位作者 赵小艳 苏有锦 《地震研究》 CSCD 北大核心 2008年第3期203-208,共6页
从1998~2006年间云南地区数字地震台网记录中,选用有4个以上台记录到的震相清晰的直达Pg波、Sg波的到时(包含Pg、Sg的到时差在20~25s的远台和小于0.5s的近台),计算出云南地区数字地震波的波速比(Vp/Vs),并分析了其区域分布... 从1998~2006年间云南地区数字地震台网记录中,选用有4个以上台记录到的震相清晰的直达Pg波、Sg波的到时(包含Pg、Sg的到时差在20~25s的远台和小于0.5s的近台),计算出云南地区数字地震波的波速比(Vp/Vs),并分析了其区域分布特征。结果表明:1998~2006年云南地区波速比月均值为1.685,滇西南地区的月均值高于云南地区的月均值;滇西地区的月均值变化幅度相对较小,2002年10月至2004年11月间的月均值低于云南地区的月均值。2005年云南地区的波速比整体偏高,平均值达1.74,高于多年均值,可能是2004年印尼8级大震后云南地区波速比的一种新变化。 展开更多
关键词 数字地震波 波速比 直达波 云南地区
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常用时频分析方法在数字地震波特征量分析中的应用 被引量:20
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作者 姚家骏 杨立明 冯建刚 《西北地震学报》 CSCD 北大核心 2011年第2期105-110,共6页
地震波属于非平稳信号,传统的傅立叶变换因缺乏信号局域性的信息而无法对非平衡信号进行全面描述。对此时频分析是有力的分析工具。本文简介了短时傅立叶变换(STFT)、S变换、CWD分布、ZAM分布四种时频分析方法,通过对算例及实际地震信... 地震波属于非平稳信号,传统的傅立叶变换因缺乏信号局域性的信息而无法对非平衡信号进行全面描述。对此时频分析是有力的分析工具。本文简介了短时傅立叶变换(STFT)、S变换、CWD分布、ZAM分布四种时频分析方法,通过对算例及实际地震信号的分析,总结出这四种时频分析方法在分辨地震波中的应用效果及优缺点。 展开更多
关键词 时频分析 短时傅立叶变换 S变换 CWD分布 ZAM分布 数字地震波
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数字地震波时频分析 被引量:4
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作者 戴勇 高立新 +3 位作者 张帆 尹战军 郝美仙 倪铭 《地震地磁观测与研究》 2017年第6期10-16,共7页
选取具有较高分辨率和较低交叉项的赵—阿特拉斯—马克斯(ZAM)方法,进行数字化地震波时频处理。结果显示:(1)S波高能量密度区域处于低频段,其频带比P波高能量密度区域窄,且S波能量密度比P波大1个数量级;(2)天然地震的高能量密度分布较... 选取具有较高分辨率和较低交叉项的赵—阿特拉斯—马克斯(ZAM)方法,进行数字化地震波时频处理。结果显示:(1)S波高能量密度区域处于低频段,其频带比P波高能量密度区域窄,且S波能量密度比P波大1个数量级;(2)天然地震的高能量密度分布较为离散,爆破的高能量密度分布较为集中。 展开更多
关键词 数字地震波 时频分析 赵—阿特拉斯—马克斯方法 能量密度
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时频分析方法及在地震波谱研究中的应用 被引量:13
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作者 张帆 钟羽云 +2 位作者 朱新运 熊丹 周昕 《地震地磁观测与研究》 2006年第4期17-22,共6页
地震波是一种非平稳信号,傅立叶分析已不适合。时频分析能对非平稳信号进行分析,并给出地震波信号能量的时间-频率分布。但是在时频分析时,存在交叉干扰项,会带来一些错误的信息。本文讨论了波恩-约旦(Born-Jordan)时频分布、乔伊-威廉... 地震波是一种非平稳信号,傅立叶分析已不适合。时频分析能对非平稳信号进行分析,并给出地震波信号能量的时间-频率分布。但是在时频分析时,存在交叉干扰项,会带来一些错误的信息。本文讨论了波恩-约旦(Born-Jordan)时频分布、乔伊-威廉斯(Choi-Williams)时频分布、赵-阿特拉斯-马克斯(Zhao-Atlas-Marks)时频分布3者之间抑制和消除交叉干扰项的特点,认为赵-阿特拉斯-马克斯(Zhao-Atlas-Marks)时频分布抑制交叉干扰项的效果和时频聚集性更好,更适合于分析地震波。 展开更多
关键词 非平稳信号 时频分布 数字地震波 交叉干扰项 时变频谱
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青海玉树单台地震序列的尾波Q值研究 被引量:6
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作者 王培玲 孙洪斌 陈玉华 《高原地震》 2007年第3期21-24,共4页
利用玉树单台记录到的2006年7月19日玉树Ms5.4级地震序列的数字地震波形资料,计算了不同频率下该序列尾波Q值的变化特征,为今后将数字地震资料应用到地震预报工作中提供了参考依据。
关键词 数字地震波 玉树地震序列 尾波Q值
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新源、和静地震序列尾波Q值衰减特征研究 被引量:1
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作者 孙吉泽 宋春燕 《内陆地震》 2013年第2期140-145,共6页
利用新源单台记录到的2012年6月30日新源、和静MS6.6地震序列以及震前的数字地震波资料,分析地震前后尾波Q值的变化特征。结果表明,在地震前后Q值有明显变化,而随着强震后能量的释放,Q值趋于平缓。通过对Q值变化特征的研究,可以为地震... 利用新源单台记录到的2012年6月30日新源、和静MS6.6地震序列以及震前的数字地震波资料,分析地震前后尾波Q值的变化特征。结果表明,在地震前后Q值有明显变化,而随着强震后能量的释放,Q值趋于平缓。通过对Q值变化特征的研究,可以为地震预报工作提供可靠依据。 展开更多
关键词 新源、和静MS6 6地震 数字地震波 尾波Q值
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“强地震短期预测及救灾技术研究”项目概述
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作者 张晓东 张永仙 《国际地震动态》 2004年第1期22-23,共2页
关键词 地震短期预测 防震减灾 监测预报 数字地震波
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高斯射线束在工程物探中的应用 被引量:4
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作者 江玉乐 雷宛 +1 位作者 张朝霞 杨晓薇 《煤田地质与勘探》 CAS CSCD 北大核心 2006年第6期65-68,共4页
以高斯射线束在工程物探中的应用和研究为出发点,根据工程物探的特点,试验并分析了频率对地震剖面结果的影响,总结出了能够分辨薄层的最佳频率;在进行了多种浅层模型的计算试验并对该方法技术验证后,将其应用到3个工程物探实际资料上模... 以高斯射线束在工程物探中的应用和研究为出发点,根据工程物探的特点,试验并分析了频率对地震剖面结果的影响,总结出了能够分辨薄层的最佳频率;在进行了多种浅层模型的计算试验并对该方法技术验证后,将其应用到3个工程物探实际资料上模拟验证,取得了比较理想的效果和初步认识。 展开更多
关键词 高斯射线束 工程物探 频率 地震波数字模拟
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Propagation simulation and attenuation law analysis of seismic wave in elastoplastic tunnel rock medium 被引量:2
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作者 赵同彬 李建功 +1 位作者 肖亚勋 程国强 《Journal of Coal Science & Engineering(China)》 2007年第4期503-506,共4页
The energy caused by the dynamic impact in mining engineering forth release and spread by the way of seismic waves, monitoring is an effective way for forecasting mine dynamical disasters, such as rockburst and coal a... The energy caused by the dynamic impact in mining engineering forth release and spread by the way of seismic waves, monitoring is an effective way for forecasting mine dynamical disasters, such as rockburst and coal and gas outburst. Three-dimensional dynamic model was built to simulate the propagating progress of seismic waves in the elastoplastic tunnel rock and analyzed the propagating law of perturbation acceleration around tunnel, based on the finite element dynamic analysis software ANSYS/L S-DYNA. The simulation results indicate that: (1) The propagation attenuation of seismic wave is a negative index relationship; (2) The acceleration amplitude of seismic wave decays rapidly in near-field and decays slowly in far-field; (3) When the perturbation is generated in the dead ahead of tunnel, the acceleration of seismic wave become smaller and smaller away from the roadway-rib;(4) The elastic and plastic stress state of tunnel rock is also an important factor for propagation process of wave, the energy of seismic wave is mainly consumed for geometric spreading and plastic deformation in propagation in the elastoplastic medium model. 展开更多
关键词 seismic wave tunnel rock numerical simulation ATTENUATION
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A Review on the Study of "Repeating Earthquakes" by Cross-correlation of Seismic Waveforms
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作者 Li Yutong Jiang Changsheng 《Earthquake Research in China》 2012年第3期277-291,共15页
"Repeating earthquakes",identified by cross-correlation of seismic waveforms,are found to be much more abundant in the nature than conventionally expected. In recent years, with the development of digital se... "Repeating earthquakes",identified by cross-correlation of seismic waveforms,are found to be much more abundant in the nature than conventionally expected. In recent years, with the development of digital seismic networks, waveform cross correlation and "repeating earthquakes"have caused much attention to the measuring the variation of crustal medium properties and estimation of location accuracy and fault slip rate at depth or earthquake recurrence intervals. Moreover, as a useful tool, the "repeating earthquake" approach has also been used in the assessment of the accuracy of seismic phase picking,hypocenter location,fault structure and physics of earthquake sources,as well as the study of earthquake prediction. In this paper, we summarized the latest research and applications of "repeating earthquakes". 展开更多
关键词 Repeating earthquake Waveform cross-correlation Variation of crustalmedia Location accuracy evaluation Fault slip rate at depth
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Measurement of Earthquake Size
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作者 Chen Zhangli Chen Hanlin +3 位作者 Zhao Cuiping Wang Qincai Hua Wei Zhou Lianqing 《Earthquake Research in China》 2014年第3期285-298,共14页
The paper begins with a brief review of the research history of earthquake size measurement. On this basis, the author pointed out the following points: ① In recent decades, ML, mb (mH ), Ms magnitude scales are w... The paper begins with a brief review of the research history of earthquake size measurement. On this basis, the author pointed out the following points: ① In recent decades, ML, mb (mH ), Ms magnitude scales are widely used as measures of earthquake size. However, these magnitude scales have a deficiency of "overgeneralization" and "magnitude saturation". Moreover, since they do not fully take into account the regional difference of seismic attenuation, especially the difference of site effects on the amplification of ground motion, these magnitude scales are but inaccurate measures of earthquake size. ② Seismic moment M0 not only has clear physical meaning, but also overcomes the deficiencies existing in ML, mb (mB ) and Ms magnitude scales, so it is the most suitable physical quantity for measuring earthquake size scientifically. In order to continue to use the term "magnitude", Kanamori defined the moment magnitude scale Act. Although its prerequisite assumptions remain to be studied, it is still a reasonable scale used as a measure of the relative size of an earthquake. ③ For measuring the earthquake size more scientifically, we must make full use of a large amount of waveform data from modern regional digital seismograph networks, strengthen the research on seismic wave attenuation characteristics, site effect, calculation of source parameters and the related scaling relations. In improving the measurement methods for ML, mb (mB ) and Ms magnitude, we should focus on the improvement of Mw scale and carry forward the work as gradually taking Mw magnitude scale as the uniform physical quantity to measure the relative size of earthquakes, so as to lay a more solid foundation for research in earthquake science and earthquake prediction. 展开更多
关键词 EARTHQUAKE MEASUREMENT MAGNITUDE Seismic moment ENERGY Stressdrop
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Rayleigh Wave Group Velocity Maps of East Guangdong and Its Surrounding Regions from Ambient Seismic Noise Tomography
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作者 Huang Yuanmin Shen Yusong Yang Maling 《Earthquake Research in China》 2013年第4期490-500,共11页
We perform Rayleigh wave tomography in east Guangdong and its surrounding regions by applying the ambient noise method to broadband data recorded at 26 stations from Guangdong,Fujian and Jiangxi Digital Seismic Networ... We perform Rayleigh wave tomography in east Guangdong and its surrounding regions by applying the ambient noise method to broadband data recorded at 26 stations from Guangdong,Fujian and Jiangxi Digital Seismic Networks.Cross-correlations of verticalcomponent ambient noise data are computed in one-day segments and stacked over seven months from March to September,2011.Then Rayleigh wave group dispersion curves are measured using the frequency-time analysis method.Group velocity maps at periods from5s to 15s are inverted.The resulting group velocity maps generally show good correlation with tectonic features,reflecting the velocity variations in the shallow crust.The basin areas are clearly resolved with lower group velocities at the short periods due to thick sedimentary layers,and the mountain areas with higher group velocities due to thin sedimentary layers.The variations of group velocity on the map can draw out the distribution of basins and mountains in study areas.The geothermal field can change the group velocity obviously,and lower group velocities are always found in high geothermal areas.The velocity maps indicate that a low-velocity layer may be found in the study areas. 展开更多
关键词 Ambient seismic noise CROSS-CORRELATION Green's function Dispersion curves
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The Focal Mechanism and Characteristic of Stress Field in the Zipingpu Area before the M_S8.0 Wenchuan Earthquake
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作者 Zhang Yongjiu Zhang Zhiwei 《Earthquake Research in China》 2011年第2期227-239,共13页
Based on seismic wave records of the Chengdu digital seismic network and Zipingpu reservoir digital seismic network from August 16,2004 to May 12,2008 when the Wenchuan MS8.0 earthquake occurred,the parameters of foca... Based on seismic wave records of the Chengdu digital seismic network and Zipingpu reservoir digital seismic network from August 16,2004 to May 12,2008 when the Wenchuan MS8.0 earthquake occurred,the parameters of focal mechanisms of 486 earthquakes with magnitude larger than M1.6 in the Zipingpu reservoir area were calculated using amplitude ratio method,meanwhile the temporal-spatial variation characteristics of mechanisms and stress field were analyzed based on these parameters.Results show a low ratio of thrust earthquakes and an increased number of strike-slip earthquakes in the reservoir water area in the period from 2006 to 2008.While in the areas far from the reservoir waterfront,the thrust earthquakes took up a high proportion and the strike-slip ones did not increase.The direction of mean principal compressive stress field was deflected and disturbed differently in each area before the Wenchuan MS8.0 earthquake. 展开更多
关键词 Zipingpu reservoir Wenchuan earthquake Focal mechanism Stress field
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Compressing and Coding Method of Seismic Data
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作者 赵学军 郑宇 +2 位作者 宁书年 郭俊霞 岳俊梅 《Journal of China University of Mining and Technology》 2002年第1期95-99,共5页
Aiming at the characteristics of the seismic exploration signals, the paper studies the image coding technology, the coding standard and algorithm, brings forward a new scheme of admixing coding for seismic data compr... Aiming at the characteristics of the seismic exploration signals, the paper studies the image coding technology, the coding standard and algorithm, brings forward a new scheme of admixing coding for seismic data compression. Based on it, a set of seismic data compression software has been developed. 展开更多
关键词 data compression wavelet transform encode IMAGE
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S-wave Q structure of the crust and upper mantle beneath Yunnan from surface waves 被引量:4
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作者 CHEN Jia HU JiaFu +3 位作者 YANG HaiYan ZHANG XiaoMan WEN LiMin PENG HengChu 《Science China Earth Sciences》 SCIE EI CAS 2012年第5期858-868,共11页
A phase-matched filtering technique is applied to extract fundamental mode signals from Rayleigh waves recorded at 62 digital seismic stations in the Yunnan and Sichuan regions.We use the fundamental mode of vibration... A phase-matched filtering technique is applied to extract fundamental mode signals from Rayleigh waves recorded at 62 digital seismic stations in the Yunnan and Sichuan regions.We use the fundamental mode of vibrations at two stations that are located on the same great circle as the focus to calculate an inter-station attenuation coefficient of the Rayleigh wave with periods between 0.40 and 80.64 s,and invert for the inter-station S-wave Q-factor (Qβ) at depths of 0-200 km.The results indicate that Qβ in Yunnan is 20-140,presenting a low Qβ background with apparent lateral variation.Taking the Honghe Fault as the boundary,Qβ of the crust is only 20 on the west side,extending to a depth of 120 km.The distribution of Qβ is consistent with large-scale Cenozoic volcanic and intrusive rocks in western Yunnan,implying that the crust and mantle are in the thermally active state.In the eastern Yunnan Block,east of the Xiaojiang Fault,Qβ in the upper 120 km is 140 in the south but only 20 in the north.Additionally,around the Dukou-Chuxiong in the mid-Yunnan Block,Qβ in the lithosphere is relatively high at 60-100,corresponding to a stiff crust.This is because the suture between the Indian and Eurasian plates reversed the tension in the rifting stage into the compression of orogenesis,leading to the closure of a gap in the crust.After some time,interstitial fluids gradually disappeared,resulting in a high velocity layer in the crust and low heat flow on the surface.The Yunnan region consists of an obvious block of elevated Qβ,distributed within the low background,consistent with the distribution of heat-flow values on the surface.The Honghe and Xiaojiang faults are tectonic boundaries in addition to being boundaries between regions of high and low crustal Qβ.The low Qβ is probably the result of crustal rupture and disturbance caused by strong earthquakes and the upwelling of hot substances along the deep fault zones. 展开更多
关键词 Yunnan region attenuation of surface wave phase-matched filtering S-wave Q-factor
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