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2008年5月12日汶川大地震发生后,中国地震局迅速组织开展了强余震流动观测,沿龙门山断裂附近布设了59台强震动仪器.在观测期间发生了万余次余震,流动观测台网获得了2000多组3分量的强余震记录.本文介绍了流动观测台布设的技术方法与关键步骤,初步处理了2008年5月25日青川6.4级最大余震的地震动记录,并分析了此次地震动衰减特征.此次流动观测充分表明,在大地震发生后,及时有效地开展强震动流动观测是十分必要的,其获得的余震地震动记录可为进一步的科研工作提供宝贵的基础资料. 相似文献
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2008年5月12日汶川大地震发生后,中国地震局迅速组织开展了强余震流动观测,沿龙门山断裂附近布设了59台强震动仪器．在观测期间发生了万余次余震,流动观测台网获得了2000多组3分量的强余震记录．本文介绍了流动观测台布设的技术方法与关键步骤,初步处理了2008年5月25日青川6.4级最大余震的地震动记录,并分析了此次地震动衰减特征．此次流动观测充分表明,在大地震发生后,及时有效地开展强震动流动观测是十分必要的,其获得的余震地震动记录可为进一步的科研工作提供宝贵的基础资料． 相似文献
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四川汶川Ms8.0级地震后,甘肃省地震局在甘川交界地区布设了多个强震动流动观测站,2008年5月25日记录到了1次最大余震,震级为Ms6.4。27个强震动台站共获得了81条记录。这次强余震记录到的最近震中距为12 km,最远为485 km,其中最大加速度峰值为367.6 cm/s2,最小加速度峰值为0.8 cm/s2。相比较汶川地震的强震动记录,由于流动观测台站的布设使得本次地震的记录具有更好的线性分布,震中距也更为丰富,因而更利于研究这一地区的地震动衰减关系。利用统计方法获得了加速度峰值随震中距的衰减关系,基本服从幂函数衰减关系。这一结果对甘肃东南部地区震害研究和抗震设防具有重要的应用价值。 相似文献
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2020年10月22日11时03分37秒四川省绵阳市北川县发生MS4.7地震,四川强震动台网与预警烈度速报台网在震区建成较密集的台站,获取了532组三分量加速度记录,有助于开展区域地震动衰减和地震动特征研究.本文对强震记录进行常规处理后计算出强震动记录的相关参数,利用克里金插值方法得到地震动峰值加速度PGA和峰值速度PGV的空间分布图,长轴呈北西—南东方向.分析强震动记录PGA、PGV随距离的衰减规律,与常用衰减关系预测值进行对比,此次地震PGA的衰减特性与俞言祥和汪素云(2006)提出的中国西部地区水平向基岩加速度衰减关系有较好的一致性.北川MS4.7地震获得的密集强震动记录为建立区域衰减关系,以及开展基于经验格林函数方法(EGFM)再现大震强地震动场展布等研究提供了重要的数据支撑. 相似文献
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对2013年7月22日甘肃岷县—漳县地震获取的273条主余震加速度记录进行格式转换、基线校正和滤波等常规处理,分析该地震主震(M_S6.6)和余震(M_S5.6)两次地震记录的幅值、持时以及反应谱特征,发现M_S6.6主震记录的PGA范围在0.728～177.5 gal间,M_S5.6余震记录的PGA范围在0.732～69.3 gal间;将观测数据与霍俊荣和第五代《中国地震动参数区划图》地震动衰减关系进行对比,发现霍俊荣衰减关系更吻合于此次地震的主余震加速度衰减;绘制主余震5%～95%重要持时分布图,并针对主震62MXT反应谱和本地设计谱以及近些年国内主要强震震中反应谱开展比较分析;最后研究土层台、基岩台、相同台站各个震级反应谱的特征。 相似文献
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2013年7月22日甘肃省定西市岷县漳县交界发生6.6级地震,国家强震动台网在甘肃、四川和陕西的64台强震仪触发并获得了主震加速度记录。本文对强震动记录进行了常规处理,统计了强震动记录数量随震中距的分布,绘制了空间地震动加速度等值线图;通过观测数据与霍俊荣和意大利新一代地震动衰减公式对比,分析了峰值加速度(PGA)及谱加速度衰减关系,发现此次地震观测数值远低于常用地震动预测值;利用渭河盆地的远场记录验证了远场地震动卓越周期变大的特点以及场地对记录的影响;参考岷县地区地质特点并通过分析宏观烈度及地震动的谱烈度,初步确定了地震震害与烈度的相关性。 相似文献
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2008年"5·12"汶川特大地震发生后,固定及流动台站获得了数量可观的余震地震动数据,为地震危险性分析和地震动衰减规律研究提供了丰富的数据。通过Gutenberg-Richter关系分析得到汶川地震余震震级-频度分布（FMD）,结合Båth定律预估得到逼近实际的最大预估余震震级,基于修正的Omori定律拟合得到余震发生率与主震后时间的关系。主余震统计特性显示Ms4.0~6.4范围内的余震记录震中距及震级分布相对均匀,可作为建立地震动衰减规律的依据。故针对土层地表及基岩地表分别进行了EW、NS和UD三个方向的统计回归分析,给出了2种地表情况下三向地震动峰值加速度的定量衰减关系表达式。 相似文献
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芦山7.0级地震强震动记录及其震害相关性 总被引：4，自引：0，他引：4
2013年4月20日芦山地震中的强震动记录是我国自2008年汶川地震后再一次比较全面地获得的高质量的数字强震动记录。国家数字强震动台网共获得3分量自由场记录114组,成都地震烈度速报台网获得63组。文章对强震动记录进行了常规处理,统计了强震动记录随断层距的数量分布情况,绘制了空间地震动加速度等值线图。结合芦山地震震源机制解和破裂过程研究成果,选取典型记录,分析加速度、速度时程的波形、振幅等特征,识别了此次地震滑冲现象,估算了竖向最大永久位移。通过利用观测数据与国外的地震动预测公式对比,分析了不同周期反应谱地震动幅值及加速度反应谱衰减规律,阐明了此次地震的地震动在近场高频成分较卓越的特点。震后现场考察了3个典型强震动台站附近建筑物震害,分析了地震动与工程震害的相关性,地震烈度的评定反映了地震破坏的程度。 相似文献
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近场强震数据是地震观测的主要数据类型之一,但尚未广泛用于震源参数快速和常规测定.作者利用2017年8月8日九寨沟地震的近场强震数据,分别基于中国地震台网中心和美国地质调查局的定位结果,采用迭代反褶积和叠加（Iterative Deconvolution and Stacking, IDS）方法反演得到了两个破裂模型.反演结果显示,两个破裂模型除在时间上存在大约2.5 s的偏移外,在其他破裂特征上都极其相似,表明强震数据反演并不严重依赖地震定位结果.破裂过程大约持续8~10 s,释放的地震矩在6.9×1018 Nm左右,对应的矩震级约为MW6.5.走向方向上,破裂覆盖了震中西北15 km至震中东南10 km的区域,整体表现为不对称的双侧破裂模式,其中西北方向的破裂略占优势.深度方向上,主要破裂集中在0~10 km的较浅区域.这些特征与目前的地震学和大地测量学结果基本一致,表明在当前的数据条件下,即使定位结果存在不确定性,通过反演强震数据也能够独立可靠地确定中强地震的破裂过程.特别地,未来强震数据的数据质量和获取效率得到进一步改进和提升后,这一工作有望成为震后快速确定破裂过程的主要方式之一,在震后应急工作中发挥积极作用. 相似文献
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唐山响堂三维场地影响观测台阵 总被引：10，自引：0，他引：10
１９９４年７月中国地震局工程力学研究所在唐山余震区响堂镇建成了我国第一个三维场地影响观测台阵。该台阵目前有四个测点,分别布设在基岩地表、土层地表、地下１７ｍ和地下３２ｍ处。它安装了分辨率为１６位的井下数字观测系统,主机和从机同步运行,系统时钟采用Ｏｍｅｇａ导航信号自动校对（精度１ｍｓ）,地震数据采用固态方式（ＣＭＯＳ）存储,每个测点均布设一组 量力平衡式加速度计。该台阵自投入运行至１９９７年１２月 相似文献
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随着中国“数字地震观测网络”项目的启动,中国强震动观测网络将新增大量先进的数字化、网络地震动记录仪,该类型仪器具备大存储容量、自动震动触发、自动报警,本地串口通讯、远程Modem通讯、远程TCP/IP网络通讯等功能,这些先进功能为强震动数据记录、存储、强震动记录以及相关地震信息自动传输创建了硬件基础.新增的大量强震动观测设备,使得强震台网的密度进一步加大,因此可利用的强震动观测数据大大增加,但目前中国的强震观测网络无法及时的收集、分析、处理这些海量数据.而随着国家级、区域级台网中心的进一步扩建、新建,监控中心网络硬件设备、软件齐全,通讯网络大大加强,也使得大数据分析、处理、传输成为可能,在此基础上建立强震动观测无人值守信息管理自动化成为一种可能.并且随着该自动化系统的运行,积累的强震观测记录也可建立强震观测数据仓库,并在数据仓库的基础进一步建立强震分析数据挖掘方法. 相似文献
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Rapid source inversions of the 2023 SE Türkiye earthquakes with teleseismic and strong-motion data 
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下载免费PDF全文 Chenyu Xu Yong Zhang Sibo Hua Xu Zhang Lisheng Xu Yuntai Chen Tuncay Taymaz 《地震科学（英文版）》2023,36(4):316-327
We conducted rapid inversions of rupture process for the 2023 earthquake doublet occurred in SE Türkiye, the first with a magnitude of MW7.8 and the second with a magnitude of MW7.6, using teleseismic and strong-motion data. The teleseismic rupture models of the both events were obtained approximately 88 and 55 minutes after their occurrences, respectively. The rupture models indicated that the first event was an asymmetric bilateral event with ruptures mainly propagating to the northeast, while the second one was a unilateral event with ruptures propagating to the west. This information could be useful in locating the meizoseismal areas. Compared with teleseismic models, the strong-motion models showed relatively higher resolution. A noticeable difference was found for the MW7.6 earthquake, for which the strong-motion models shows a bilateral event, rather than a unilateral event, but the dominant rupture direction is still westward. Nevertheless, all strong-motion models are consistent with the teleseismic models in terms of magnitudes, durations, and dominant rupture directions. This suggests that both teleseismic and strong-motion data can be used for fast determination of major source characteristics. In contrast, the strong-motion data would be preferable in future emergency responses since they are recorded earlier and have a better resolution ability on the source ruptures. 相似文献
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Since 1990, digital strong-motion accelerographs and global positioning system (GPS) instruments have been widely deployed
in the Taiwan region (Shin et al. 2003; Yu et al. 2001). The 1999 Chi-Chi, Mw 7.6 earthquake and the 2003 Chengkung, Mw 6.8 earthquake were well recorded by both digital accelerographs
and GPS instruments. These data offer a good opportunity to determine coseismic displacements from strong-motion records and
to compare the results with those derived from GPS measurements. As noted by Boore (2001), a double integration of the acceleration data often leads to unreasonable results, and baseline corrections are therefore
required in most cases before the integration. Based on the works of Iwan et al. (1985) and Boore (2001), we developed an improved method for baseline correction and validated it using an extensive set of data from shake-table
tests of a known “step” displacement on 249 accelerographs. Our baseline correction method recovered about 97% of the actual
displacement from the shake-table data. We then applied this baseline correction method to compute coseismic displacements
from the strong-motion data of the Chi-Chi and Chengkung earthquakes. Our results agree favorably with the coseismic displacements
determined by the GPS measurements at nearby sites. The ratio of seismic to geodetic displacement varies from 0.78 to 1.41,
with an average of about 1.05. 相似文献
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一幢钢筋混凝土建筑结构的强地震反应观测 总被引：3，自引：2，他引：3
介绍了美国加州强震观测计划（CSMIP）中一幢建筑结构地震反应台阵的观测方案，描述了被观测结构的有关情况，给出了该台阵于1994年美国北岭地震中获得的结构地震反应的观测资料。 相似文献
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COSEISMIC DISPLACEMENT FIELD OF THE WENCHUAN EARTHQUAKE DERIVED FROM STRONG MOTION RECORDS AND APPLICATION IN SLIP INVERSION 下载免费PDF全文
下载免费PDF全文 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 MS8.0 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
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局部场地条件是决定场地地震动强度和频谱的重要因素，基于强震动和脉动记录的统计分析，获取表征场地条件影响的特征参数已成为确定工程场地设计地震动的较经济和实用方法，特别是对于大范围或难以开展现场勘测的工程场地。利用日本KiK-net台网强震动记录计算分析了台站场地地震动水平/竖向谱比（HVSR）与地表/基底谱比（SBSR）的差异，揭示SBSR/HVSR与HVSR呈对数线性分布的统计特征，并给出其定量关系，据此提出表征场地对地震动影响的修正水平/竖向谱比法。修正水平/竖向谱比法具有仅需地表观测记录的优势，并进一步考虑了场地竖向地震效应对水平/竖向谱比法精度的影响，更能合理地表征场地对地震动的影响。 相似文献
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Predictive models for estimating strong-motion duration in sites characterized by soft-soil profiles are presented in this paper. The models were developed using a strong-motion database that includes observations from subduction interface earthquakes that occurred from 1989 to 2020 and recorded in Mexico City, which is located at source-to-site distances up to 600 km. A linear mixed-effects regression model, which is a statistical fitting procedure that allows to consider the correlation structure of grouped data, was used to develop the predictive models. Relative significant duration was selected to measure strong-motion duration. This measure can be directly associated with the accumulation of energy of the ground movement. The proposed predictive models relate relative significant duration with moment magnitude, either hypocentral distance or closest distance to the rupture plane, and dominant period of the soil. Regression analyses were performed grouping the ground-motion data by both seismic event and site class. Model assumptions, such as homoscedasticity, normality, and linearity of effects, were verified from residual analyses. From the results, the expected value of the natural logarithm of relative significant duration was found to be ～1.2 times greater for an earthquake with a moment magnitude equal to 8.0 than for one of 6.0. An insightful discussion about the sources and character of the uncertainties detected in the proposed predictive models is also presented in this study. The predictive models proposed in this paper are of valuable application in seismic and structural engineering because they allow to circumscribe properly the dimension and randomness of strong-motion duration. 相似文献