芦山M_s7.0地震前水平位移和同震水平位移研究
详细信息 本馆镜像全文    |  推荐本文 | | 获取馆网全文
摘要
本文利用"中国地壳运动观测网络(二期)"多个GPS连续观测站观测数据处理结果,将2013年4月20日四川芦山Ms7.0地震区域参考框架同震水平位移与全球参考框架同震水平位移进行比较,结果表明两组框架解一致,说明两种参考框架均可当作位错参考框架,也即全球参考框架同震水平位移也可视为区域参考框架同震水平位移.区域参考框架下GPS连续观测站地震前的水平位移和同震水平位移结果表明,震前数年,SCTQ站西侧的GPS站构造运动十分显著,而该站水平位移却很小,即出现反常的闭锁.但该站的同震水平位移使其弹性回跳至正常构造水平位移水平,因此SCTQ站震前的位移闭锁是水平位移空间分布中的异常,是芦山Ms7.0地震的前兆.水平位移时空变化表明,该站震前和震时位移完全符合里德的弹性回跳理论.区域参考框架中位移时间系列和同震水平位移的综合研究有助于对芦山地震地壳运动前兆的认识和解释.尽管本文未能直接采用其它GPS连续观测站的资料,但结合本文和其它研究结果可以证实,震中附近其它站地震前后的变化与SCTQ站类似.基于芦山地震前水平位移和同震水平位移及其与前兆关系的研究,本文进一步讨论了GPS监测网的布设、数据处理和分析等问题.
In this paper the coseismic horizontal displacements of the M_s7.0Lushan earthquake on April 20,2013 in Sichuan,China are obtained in the global and regional reference frames from continuous GPS observations at some stations in the Crustal Movement Observation Network of China(CMONOC)and other stations.Comparison of the two sets of solutions for the coseismic horizontal displacements shows that they are in good agreement and both of the reference frames can be taken as the dislocation reference frame for the coseismic horizontal displacements of this event.So the coseismic horizontal displacements in the global reference frame can be used as coseismic horizontal displacements in the regional reference frame.The relationship between the coseismic horizontal displacements and the preseismic horizontal displacements can be analyzed reasonably with the results in the regional reference frame so as to study the crustal movements precursory to this event.Time series of preseismic displacements and the coseismic displacements in the regional reference frame at continuous GPS observation stations show that the tectonic horizontal crustal movements were quite significant at some stations west to the station SCTQ near epicenter of the Lushan earthquake,while this station showed abnormal locking in the horizontal movement.The coseismic horizontal displacements at the station SCTQ and other stations were elastic rebound to their normal horizontal tectonic movements.Therefore the locked horizontal displacements at these stations were anomalous in the spatial distribution of the horizontal displacements at the GPS stations and were precursors to the earthquake.The horizontal displacement change in time and space show that the preseismic and coseismic displacements at the station SCTQ are in good agreement with Reid's elastic rebound model.The combined studies on time series of the horizontal displacements and the coseismic horizontal displacements in the regional reference frame are important for the reasonable explanation on the crustal movements precursory to the earthquake.Though the data used in this study are limited,combination of the results in this paper with other papers suggests that the result obtained from data at the station SCTQ can be verified by the data at other GPS stations.Based on the studies on the preseismic and coeseismic horizontal displacements,some problems in the GPS monitoring networks and the data processing and analyses are discussed.
引文
顾国华.1990.形变监测网的基准与形变模型反演[J].地壳形变与地震,10(1):21-29.Gu G H.1990.Datum definition in geodynamic network and inversion of deformation models[J3.Crustal Deformation and Earthquake,10(1):21-29(in Chinese).
    顾国华,申旭辉,王敏,郑贵明,方颖,李鹏.2001.中国大陆现今地壳水平运动基本特征[J].地震学报,23(4):352-369.Gu G H,Shen X H,Wang M,Zhen G M,Fang Y,Li P.2001.General characteristics of the recent horizontal crustal movement in Chinese mainland[J].Acta Seismologica Sinica,14(4);384-393.
    顾国华,符养,王武星.2004.1999--2001年中国大陆现今地壳水平运动[J].地震学报,26(增刊):50-57.Gu G H,Fu Y,Wang W X.2004.Horizontal crustal movement in Chinese mainland from 1999 to 2001[J].Acta Seismologica Sinica,26(Suppl.):50-57.
    顾国华,王武星.2009.GPS测得的汶川大地震同震位移[J].地震,29(1):92-99.Gu G H,Wang W X.2009.Coseismic displacements of the 2008 Wenchuan M8.0 earthquake observed by GPS[J].Earthquake,29(1):92-99(in Chinese).
    顾国华,王武星,孟国杰,徐岳仁.2009.GPS测得的汶川大地震前后的地壳运动[J].武汉大学学报:信息科学版,34(11):1336-1339.Gu G H,Wang W X,Meng G J,Xu Y R.2009.Crustal movements before and after the Wenchuan earthquake as detected by GPS observations[J]].Geomatics and Information Science of Wuhan University,34(11):1336-1339(in Chinese).
    顾国华,王武星.2011.区域网GPS观测得到的汶川大地震前后的地壳垂直运动[J].地震,31(3):1-8.Gu G H,Wang W X.2011.Vertical crustal movement before and after the great Wenchuan earthquake obtained from GPS observations in the regional network[J].Earthquake,31(3):1-8(in Chinese).
    顾国华,孟国杰,方颖.2011.汶川大地震前后GPS观测的精密单历元解得到的震区地壳运动[J].地震学报,33(3):319-326.Gu G H,Meng G J,Fang Y.2011.Crustal movement in the earthquake area before and after 2008 Wenchuan earthquake as detected by precise single epoch positioning of GPS observations[J].Acta Seismologica Sinica,33(3):319-326(in Chinese).
    顾国华.2012.GPS:地震预测利器[G]∥科学与中国(第4卷).北京:北京大学出版社:163-184.Gu G H.2012.GPS:Useful technique for earthquake prediction[G]//Science in China(Vol.4).Beijing:Peking University Press;163-184(in Chinese).
    黄立人,顾国华.1982.静力位错理论[M].北京:地震出版社:111-177.Huan L R,Gu G H.1982.Theory of Static Dislocation[M].Beijing:Seismological Press:111-177(in Chinese).
    金明培,汪荣江,屠泓为.2014.芦山7级地震的同震位移估计和震源滑动模型反演尝试[J].地球物理学报,57(1):129-137.Jin M P,Wang R J,Tu H W.2014.Slip model and co-seismic displacement field derived from near-source strong motion records of the Lushan M_s7.0 earthquake on 20 April 2013[J].Chinese Journal of Geophysics,57(1):129-137.doi:10.6038/cjg20140112(in Chinese).
    牛安福,顾国华,曹景鹏,张凌空,闫伟,赵静,吉平.2013a.芦山M_s7.0地震前远、近场形变时空演化特征研究[J].地震学报,35(5):670-680.Niu A F,Gu G H,Cao J P,Zhang L K,Yan W,Zhao J,Ji P.2013a.On the preseismic deformation changes prior to the Lushan M_s7.0 earthquake[J].Acta Seismologica Sinica,35(5):670-680(in Chinese).
    牛安福,张凌空,李媛,闫伟,赵静,吉平.2013b.芦山Ms7.0级地震前的形变空区特征研究[J].震灾防御技术,8(4):341-350.Niu A F,Zhang L K,Li Y,Yan W,Zhao J,Ji P.2013b.On the weak deformation area prior to the Lushan Ms7.0earthquake[J].Technology for Earthquake Disaster Prevention,8(4):341-350(in Chinese).
    武艳强,江在森,王敏,车时,廖华,李强,李鹏,杨永林,向和平,邵志刚,王武星,魏文薪,刘晓霞.2013.GPS监测的芦山7.0级地震前应变积累及同震位移场初步结果[J].科学通报,58(20):1910-1916.Wu Y Q,Jiang Z S,Wang M,Che S,Liao H,Li Q,Li P,Yang Y L.Xiang H P,Shao Z G,Wang W X,Wei W X,Liu X X.2013.Preliminary results pertaining to coseismic displacement and preseismic strain accumulation of the Lushan M_s7.0 earthquake,as reflected by the GPS surveying[J].Chinese Science Bulletin,58(28/29):3460-3466.doi:10.1007/sll434-013-5998-5.
    中国地震局地震预测研究所.2013.GPS连续站测定的芦山“4·20”M_s7.0地震同震位移场数据公开[EB/OL].[2013-11-27].http://www.seis.ac.cn/manage/html/8a9080al25b29blb0125b2a3093a0002/kydt/index_3.html.Institute of Earthquake Science,China Earthquake Administration.2013.Open release of the data of the coseismic displacement field of the M_s7.0 Lushan earthquake on April 20,2013,as detected at stations of continuous GPS observations[EB/OL].[2013-11-27].http://www.seis.ac.Cn/manage/html/8a9080al25b29blb0125b2a3093a0002/kydt/index_3.html(in Chinese).
    Blewitt G.2008.Overview of the SNARF Working Group,its activities,and accomplishments[C]//8th SNARF Workshop AGU Fall Meeting.San Francisco,December 11,2008.
    Du Y J,Wang Z M,Yang S J,An J C,Liu Q,Che G W.2013.Co-seismic deformation derived from GPS observations during April 20th,2013 Lushan earthquake,Sichuan,China[J].Earthquake Science,26(3/4):153-160.
    Gu G H,Wang W,Xu Y R,Li W J.2009.Horizontal crustal movement before the great Wenchuan earthquake obtained from GPS observations in the regional network[J].Earthquake Science,22(5):471-478.
    Gu G H,Meng G J,Wang W X.2011.Anomalous crustal movements before great Wenchuan earthquake observed by GPS[J].Geod Geodyn,2(2):13-22.
    Gu GH,Wang W X.2011.Far-field crustal movements before and after the 2011 M_s9.0 Japan earthquake from GPS observations[J].Geod Geodyn.2(3):1-7.
    Gu G H,Wang W X.2013.Advantages of GNSS in monitoring crustal deformation for detection of precursors to strong earthquakes[J].Positioning,4(1):11-19.doi:10.4236/pos.2013.41003.
    Jiang Z S,Min W,Wang Y Z,Wu Y Q,Che S,Shen Z K,B(u|¨)rgmann R,Sun J B,Yang Y L,Liao H,Li Q.2014.GPS constrained coseismic source and slip distribution of the 2013 M_w6.6 Lushan,China,earthquake and its tectonic implications[J].Geophys Res Lett,41(2):407-413.doi:10.1002/2013GL058812.
    Tan H B,Shen C Y,Wei J,Zhao B.Wang J,Xuan S B.2013.Simulation of coseismic effects of the M_s7.0 Lushan earthquake[J].Geod Geodyn,4(3):12-18.

版权所有:© 2021 中国地质图书馆 中国地质调查局地学文献中心