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利用2016年4月16日日本熊本MW7.0地震震中周围94个近场强震动台的观测资料和新近改进的强震经验基线校正方法SMBLOC,尝试解算并绘制了一个内陆M7左右走滑型地震的同震位移场全貌,并反演了其震源滑动模型.与日本国土地理院(GSI)公布的该地震57个GPS同震位移结果的比较显示,两种完全不同资料、不同解算方法给出的水平同震位移场的最大幅值均为100 cm左右,均呈右旋走滑为主兼具部分正断分量的震源机制.强震最大水平和垂直永久位移分别为104.5 cm和58.0 cm, 分别出现在震中东北侧的KMMH162台和KMM005台.两种资料单独以及联合反演的震源滑动模型均表明,此次地震为北东侧破裂为主并呈双事件特征,且主要滑动均不在初始破裂点附近, 而是集中于第二次事件周围,即距离初始破裂点东北侧约20 km处的走向长约40 km、倾向宽约20 km的范围内.基于强震和GPS模型所得的最大滑动量分别为5.10 m和5.87 m,量级一致,反演矩震级均为MW7.1左右;主破裂区近地表滑动量比野外调查结果略微偏大,可能与数值效应有关.此外,还利用不同方法得到的解算结果比较了熊本地震特有的12组台间距在3 km以内的GPS-强震台站对各自的三分量同震位移,其结果表明对于M7左右的地震而言,SMBLOC方法解算同震位移时方向和幅值的可靠性下限约为2 cm. 相似文献
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利用改进的自动经验基线校正方法SMBLOC,对2016年8月24日意大利佩鲁贾MW 6.2级地震震中周围约60 km内的近场强震记录进行基线校正并尝试给出同震位移场,与GPS观测结果进行对比分析,分别独立和联合两种资料反演震源滑动模型,并根据震源模型进一步给出全空间预测位移场分布.研究结果表明:(1)两种不同的资料给出的水平位移场幅值均为cm级,且均表明断层的错动以正断为主.(2)两种同震位移场分别独立和联合反演所得的震源静态滑动范围基本一致,最大滑动均发生在震中东北侧,强震模型表现出明显的双事件特征,较大滑动分布在震中东北侧和东南侧,GPS模型在震中东南侧的滑动相对较小,其双事件特征不明显.两种模型的最大滑动量分别为0.96 m和0.86 m,较为一致,反演的矩震级均在MW 6.3左右.(3)根据震源滑动模型计算所得的佩鲁贾地震全空间预测的水平同震位移场中最大位移分布区域与震后报告中受灾严重的地区基本一致.表明在一定的条件下,利用SMBLOC方法解算震级较小的MW 6.0左右地震强震记录的同震位移场,并反演震源滑动模型具有一定的可行性,且其同震位移场和滑动模型可为震后灾害快速评估、救援力量分配、余震趋势判定等快速应急响应工作提供参考依据. 相似文献
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利用自动经验基线校正方法,分析日本2008年岩手-宫城内陆Mw6.9地震震中周围密集强震动观测台网资料,快速解算出了同震位移场分布,并据此反演了震源滑动模型.经与GPS结果比较,两种不同方法给出的同震位移幅值、方向和总体分布特征较为接近.基于相同断层面参数反演的震源模型空间展布形态、主要滑动范围、平均和最大滑动量、滑动方向以及由模型计算的矩震级等均吻合较好,从而验证了方法的可行性.讨论了自动经验基线校正方法尚存在的问题和不足,为今后利用强震资料快速解算Mw6-7级及以上地震的同震位移场并反演震源滑动分布提供参考. 相似文献
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《地球物理学进展》2019,(6)
2018年9月4日新疆伽师发生M_S 5.5地震,震源区周边发生过数次的强震,且各震中位置相近,大致为10 km左右.由于地震观测报告给出的初始定位误差较大,余震分布较为离散,且震源区沉积层较厚,无断层出露,伽师地震的发震断层与前两次强震是否存在关联仍不清楚.本研究主要利用CAP方法对伽师地震M_S≥3.5的余震震源机制解进行解算,并利用双差定位方法对伽师地震序列进行重定位.结果表明,伽师地震主震震源机制解为节面Ⅰ走向:226°,倾角90°,滑动角0°;节面Ⅱ走向:136°,倾角90°,滑动角-180°;本次地震为走滑型地震事件,主震震源深度为10 km,余震震源机制解与主震较为一致,P轴作用近似NS向,与区域构造应力场相同.根据双差定位结果显示,余震的优势分布方向为北东向,震源深度集中在5～15 km.由余震分布特征和震源机制解,认为此次地震断层面应为节面Ⅰ,与1997年和2003年的伽师强震属于不同的发震构造.根据相关地质及地震资料分析,推测此次地震发震断层为震源区下方的隐伏断裂,此断裂很可能即为与羊达曼断裂正交的北东向隐伏直立断层,伽师地震的发生与帕米尔、南天山以及塔里木盆地的相对形变速率和升降幅度有关. 相似文献
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以UNAVCO公布的阿拉斯加地区GPS 1 Hz和30 s采样观测数据为基础,采用双差定位方法分别对两种采样率的数据进行处理分析,获得2020年7月22日阿拉斯加MW7.8地震震时地表动态变形及同震三维形变场。结果显示,震中270 km范围内高频GPS震时波形明显,最大振幅达600 mm。根据各个GPS站的动态形变波形振幅及响应时间认为,其振幅和响应时间受地震的破裂传播方向和场地效应影响较大。静态同震位移矢量指向震中,同震位移大小基本符合随震中距离增大而减小的特征,除站点AC13外,其中距离震中最近站点的最大水平位移达26.7 cm。GPS测定的同震形变表明,2020年阿拉斯加地震是发生在阿拉斯加阿留申俯冲大断裂的一次逆冲型地震。 相似文献
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本文利用近震、地方震的各种震相的走时方程，经过变换，取得相应的二次型目标函数。对目标函数用一维寻查法、均值寻查法求出其零值点的自变量，即求得各个方程的解；再用均值寻查法求得各个方程的共解，即得震源位置。随机地处理了自2000～2003年6月福建数字地震遥测台网记录到的本省及周边地区的205个地震，定位结果显示走时残差的平均值为0．25s。在可供比较的前提下，将159个地震数据的奇异值分解法的结果与本文的结果进行对比，前者的平均走时残差为0．72s，后者为0．25s，且后者的每一个地震的走时残差都比前者小。 相似文献
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利用最小二乘配置进行地壳形变分析,其结果的合理性关键在于经验协方差函数的拟合.考虑到观测数据存在粗差的情况,提出基于观测值中位数初值的抗差最小二乘配置方法和基于中位参数法的抗差最小二乘配置方法.两种方法首先分别利用观测值中位数给出观测值初始权阵以及利用中位参数法给出最小二乘配置初始解,然后均在给定协方差函数参数初始值的情况下,应用合适的等价权进行抗差估计并通过迭代计算,最终获得稳健的协方差函数参数估值及最小二乘配置解.利用本文提出的两种方法以及传统方法分别对庐山地震的GPS垂直位移数据和意大利L'Aquila地震的InSAR同震位移数据进行处理分析.结果表明:相对传统方法,基于观测值中位数初值的抗差最小二乘配置方法效果更好,更具稳健性. 相似文献
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利用于田震中300 km范围内的1个GPS连续站和12个GPS流动站数据,解算得到了2014年新疆于田MS7.3地震地表同震位移,并反演了发震断层滑动分布,探讨此次地震对周边断裂的影响.地表同震位移结果显示,GPS观测到的同震位移范围在平行发震断裂带的北东-南西向约210 km,垂直发震断裂带的北西-南东方向约为120 km,同震位移量大于10 mm的测站位于震中距约120 km以内;同震位移特征整体表现为北东-南西方向的左旋走滑和北西-南东方向的拉张特征,其中在北东-南西方向,I069测站位移最大,约为32.1 mm,在北西-南东方向,XJYT测站位移最大,约为28.1 mm;位错反演结果表明,最大滑动位于北纬36.05°,东经82.60°,位于深部约16.6 km,最大错动量为2.75 m,反演震级为MW7.0,同震错动呈椭圆形分布,以左旋走滑为主并具有正倾滑分量,两者最大比值约为2.5：1,同震错动延伸至地表,并向北东方向延伸,总破裂长度约50 km,地表最大错动约1.0 m;同震水平位移场模拟结果显示贡嘎错断裂、康西瓦断裂和普鲁断裂等不同位置主应变特征具有差异性,这种差异特征是否影响断裂带以及周围区域的应力构造特征,值得关注. 相似文献
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2008年5月12日的汶川MS8.0地震是自1976年唐山地震以来发生在中国大陆的最大灾难事件.地震发生后有人通过对GPS数据的动态处理分析认为在地震前1小时内震中附近有非常显著的地壳垂直运动发生,从而提升了地震学界对通过高频GPS观测技术实现地震短临预报的预期.高频GPS观测技术是近年来GPS技术发展的一个重要方面,在研究地震前后地壳形变短期变化过程、地震震源破裂过程等方面取得了非常广泛的应用,但数据解算的精度和可靠性还是受到多种因素的制约.文中提出了一种基于数据静态处理得到的载波相位观测残差来分析测站位置动态变化的方法,并采用这种方法对汶川地震前震中附近几个GPS连续站的数据进行分析,结果表明汶川地震前震中附近并不存在显著的地壳运动. 相似文献
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高频GPS可以实时获取地表位移数据,在地震学中有十分重要的现实应用,比如快速获取震中、震级、地震烈度甚至震源破裂过程.本文以汶川地震为例,首先利用近场7个GPS台站数据反演震中位置,由于高频GPS和测震学确认的震相不一致,两种震中结果相距约15.7 km.然后对高频GPS和强震动数据进行了比较分析,我们的统计结果表明,尽管由于工作原理不同,高频GPS数据中的地震动峰值与强震记录相比存在明显差异,但是高频GPS记录的PGA、PGV和PGD同样可以作为计算地震烈度的指标.进而,使用SMBLOC程序对强震记录进行事后的基线偏移校正,得到与实时高频GPS精度相当的地表位移序列.最后,采用移动平均窗口对这些位移数据作平滑,基于最速下降法和OKADA模型,对汶川地震断层破裂的过程进行了回溯性准实时反演.结果表明,汶川地震主断层由西南向东北方向破裂,以14∶28∶04为基准,在震后20 s提供初始震级MW7.0,震后70 s震级稳定在MW7.8,但断层仍在破裂,在震后159 s根据位移波形判断事件基本结束.研究表明,实时地表位移数据可以快速准确获取强震震级和破裂方向,从而使得高频GPS将对现有地震预警系统提供很好的补充. 相似文献
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Coseismic displacement estimate of the 2013 M_S7.0 Lushan,China earthquake based on the simulation of near-fault displacement field 
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下载免费PDF全文 《地震科学（英文版）》2016,(6)
Usually, GPS observation provides direct evidence to estimate coseismic displacement. However, GPS stations are scattered, sparse and cannot provide a detailed distribution of coseismic displacement. Strong ground motion records share the same disadvantages as GPS in estimating coseismic displacement. Estimations from In SAR data can provide displacement distributions; however, the resolution of such methods is limited by the analysis techniques. The paper focuses on estimating the coseismic displacement of the M_S7.0 Lushan earthquake on April 20, 2013 using a simulation of the wave field based on the elastic wave equation instead of a quasi-static equation. First, the media and source models were constructed by comparing the simulated velocity and the record velocity of the ground motion. Then simulated static displacements were compared with GPS records. Their agreement validates our results. Careful analysis of the distribution of simulated coseismic displacements near the fault reveals more details of the ground motion. For example, an uplift appears on the hanging wall of the fault,rotation is associated with the horizontal displacement, the fault strike and earthquake epicenter provide the main control on motion near the faults, and the motion on the hanging wall is stronger than that on the footwall. These results reveal additional characteristics of the ground motion of the Lushan earthquake. 相似文献
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Coseismic displacement estimate of the 2013 <Emphasis Type="Italic">M</Emphasis><Subscript>S</Subscript>7.0 Lushan,China earthquake based on the simulation of near-fault displacement field 下载免费PDF全文
下载免费PDF全文 Hong Zhou 《地震科学（英文版）》2016,29(6):327-335
Usually, GPS observation provides direct evidence to estimate coseismic displacement. However, GPS stations are scattered, sparse and cannot provide a detailed distribution of coseismic displacement. Strong ground motion records share the same disadvantages as GPS in estimating coseismic displacement. Estimations from InSAR data can provide displacement distributions; however, the resolution of such methods is limited by the analysis techniques. The paper focuses on estimating the coseismic displacement of the M S7.0 Lushan earthquake on April 20, 2013 using a simulation of the wave field based on the elastic wave equation instead of a quasi-static equation. First, the media and source models were constructed by comparing the simulated velocity and the record velocity of the ground motion. Then simulated static displacements were compared with GPS records. Their agreement validates our results. Careful analysis of the distribution of simulated coseismic displacements near the fault reveals more details of the ground motion. For example, an uplift appears on the hanging wall of the fault, rotation is associated with the horizontal displacement, the fault strike and earthquake epicenter provide the main control on motion near the faults, and the motion on the hanging wall is stronger than that on the footwall. These results reveal additional characteristics of the ground motion of the Lushan earthquake. 相似文献
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随着川滇地区强震记录的不断增加,为了建立更符合该区域地震动特征的预测模型,文中基于该区域现有的地震动数据,通过随机效应回归模型建立适用于川滇地区的地震动预测模型;2021年5月21日,云南省大理州漾濞县发生6.4级地震,为了分析文中预测模型对漾濞地震的适用性,首先根据预测模型的适用范围选取合适的漾濞地震数据,计算真实记... 相似文献
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Strong motion displacement waveforms using 10‐Hz precise point positioning GPS: an assessment based on free oscillation experiments 下载免费PDF全文
下载免费PDF全文 Fanis Moschas Antonio Avallone Vasso Saltogianni Stathis C. Stiros 《地震工程与结构动力学》2014,43(12):1853-1866
The recently developed precise point positioning (PPP) technique permits to compute instantaneous coordinates of a GPS station relatively to distant reference stations and waveforms of ground displacements during strong motions at the 1 Hz level. This is another application of GPS, different from the computation of static coseismic movements or of accurate monitoring of dynamic displacements of structures using a static receiver and a nearby moving receiver (DGPS). Recently, earthquake ground displacement waveforms using 10‐Hz GPS data have also been calculated, but no independent evidence to assess their quality exists. To overcome this problem, we evaluated the output of 10‐Hz PPP results on the basis of supervised learning experiments. Semistatic and dynamic displacements (damped harmonic oscillations) of known characteristics of the order of a few centimeter were produced and were recorded by GPS, an accelerometer, and a robotic total station. Time series of instantaneous displacements were analyzed using different PPP techniques and were compared with reference (true) values derived from DGPS and the other sensors. Our analysis revealed that the PPP‐derived coordinates are contaminated by long‐period noise but they can display the details of semistatic displacements, while their short‐period component describes well the pattern of waveforms and spectra (at least up to 4 Hz) of dynamic displacements, with up to 20 mm accuracy for isolated points. These results indicate that 10‐Hz PPP‐GPS is useful for earthquake engineering and can safely be used to reconstruct waveforms of deflections of the ground and of various points on structures during strong motions. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Based on presumed active fault and corresponding model, this paper predicted the near-fault ground motion filed of a scenario earthquake （Mw=6 3/4 ） in an active fault by the explicit finite element method in combination with the source time function with improved transmitting artificial boundary and with high-frequency vibration contained. The results indicate that the improved artificial boundary is stable in numerical computation and the predicted strong ground motion has a consistent characteristic with the observed motion. 相似文献
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M. Bouchon S. Gaffet C. Cornou M. Dietrich J.P. Glot F. Courboulex A. Caserta G. Cultrera F. Marra R. Guiguet 《Journal of Seismology》2000,4(4):517-523
We found extensive evidence that the vertical ground accelerations produced during the largest shock (M = 6.0) of the 1997 Umbria-Marche earthquake sequence exceeded 1g in two areas close to the heavily-damaged villages of Annifo and Colle Croce. This evidence comes from the striking observation of thousands of freshly fractured and broken rocks and stones in these areas. Some of the broken stones lie isolated on soft detritic soil while others had been previously piled up, probably a long time agoto clear the fields for farming. The freshness of the cuts and fractures and the consistency of the observations for thousands of rocks and stones in these areas indicate that these rocks were thrown upwards during the earthquake, with breakage occurring at the time of impact. Ground motion calculations consistent with the static deformation inferred from GPS and interferometry data, show that the broken stones and rocks are found in the zone where the strongest shaking took place during the earthquake and that most of the shaking there was vertical. 相似文献
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2017年8月8日在四川阿坝州九寨沟县发生了MS 7.0地震,这是继2008年四川汶川MS 8.0地震和四川芦山MS 7.0地震后在此地区发生的又一强震。本研究对此次地震中的66组主震记录进行了常规校正处理,基于此分析了此次地震中典型台站——九寨百合台站的地震动特征,并通过地震动的峰值加速度、反应谱参数分析了近场效应特征。研究结果表明:九寨百合台站的三分量峰值加速度都超过了100 gal,而地震动持时相对较短,并且三分量反应谱在短周期大于Ⅷ度多遇地震设计谱,小于Ⅷ度罕遇地震设计谱;由于九寨沟地震属于典型的走滑型地震,因此地震动参数的方向性特征不明显;九寨沟地震的地震动的峰值加速度以及反应谱谱值小于同等震级的芦山地震,并且小于几个典型衰减关系的预测值。对九寨沟地震的地震动参数特征研究表明,此次地震是一次震级较大、但灾害损毁程度较低的地震。 相似文献