化爆标定地震定位方法研究
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摘要
定位仿真表明,若标定震源在网内,震中偏差和震源深度偏差等值线都是以标定震源为圆心的同心圆,网内大约30%的事件,震中偏差为5%;如果标定震源位于台网一侧,约10%事件的震中误差为10%。无论标定源在网内还是在网外,计算震中都向标定震源方向移动,距标定点愈远,定位偏差愈大。速度标定定位显示,规则地震台网中对称线上的震源定位是不可靠的。实际网内化爆标定定位表明,对于网内事件,爆炸邻域定位精度比速度标定定位精度高;对于网外事件,邻域标定定位精度比速度标定定位精度低。
Location emulation present some significant results. When a calibration source is situated inside the seismic network, the curves of equivalent errors for epicenters and focal depths are concentric circles that the center of the circles is the calibration source, and approximate 30% events within the network, which surround the calibration source, show probubly 5% epicenter deflections. When a calibration source is located outside the network, approximate 10% events, which also surround the calibration source, shows about 10% epicenter errors. Whether the calibration source is inside the network or not, the computed epicenters all move toward the calibration source. The farther the calibration distance is,the larger the location deflection. Location results of the events calculated by velocity calibration, which are situated at symmetrical lines of a network, are not extremely reliable. The results obtained by the explosive calibration,in practice,can be summarized as follows: When the calibration source located inside the net, location precision of the events within net adopted vicinal calibration is higher than that of the events adopted velocity calibration, however, location precision of the events outside the net adopted vicinal calibration is lower than that of the events adopted velocity calibration.
Location emulation present some significant results. When a calibration source is situated inside the seismic network, the curves of equivalent errors for epicenters and focal depths are concentric circles that the center of the circles is the calibration source, and approximate 30% events within the network, which surround the calibration source, show probubly 5% epicenter deflections. When a calibration source is located outside the network, approximate 10% events, which also surround the calibration source, shows about 10% epicenter errors. Whether the calibration source is inside the network or not, the computed epicenters all move toward the calibration source. The farther the calibration distance is,the larger the location deflection. Location results of the events calculated by velocity calibration, which are situated at symmetrical lines of a network, are not extremely reliable. The results obtained by the explosive calibration,in practice,can be summarized as follows: When the calibration source located inside the net, location precision of the events within net adopted vicinal calibration is higher than that of the events adopted velocity calibration, however, location precision of the events outside the net adopted vicinal calibration is lower than that of the events adopted velocity calibration.
引文
李学政、何永锋、雷军等,1999,神经网络方法在爆炸地震震中定位方面的应用,地震地质,21(1):77~82。
赵仲和,1983,多重模型地震定位程序及其在北京台网的应用,地震学报,5(2):242~254。
Li Xue-zheng,Lei Jun,2001,Study onthe method of optional location on explosion events at near-source site.Acta Seismologica.Sinica,23(3):326~333.
Deichmann N,Mariano G.1992,Rupture geometryfromhigh-precisionrelative hypocenter location of microearthquake clusters.GeophysJ Int,110:501~517.
Kennett B L N,1991,IASPEI1991Seismological Tables.
Spencer.W.,1980,Relative epicenter determination using P-wave arrival-time differences.Bull.Seism.Soc.Am.70,pp171~183.
Gibowicz S J and Kijko A,1994,An Introductionto mining seismology,Academic Press,In.
Waldhauser,F.(U.S.Geological Survey);Ellsworth,W.L.,2000,ADouble-difference Earthquake location algorithm:Method andapplicationtothe Northern Hayward Fault,California.Bulletin of the Seismological Society of America,90(6):1353~1368.
赵仲和,1983,多重模型地震定位程序及其在北京台网的应用,地震学报,5(2):242~254。
Li Xue-zheng,Lei Jun,2001,Study onthe method of optional location on explosion events at near-source site.Acta Seismologica.Sinica,23(3):326~333.
Deichmann N,Mariano G.1992,Rupture geometryfromhigh-precisionrelative hypocenter location of microearthquake clusters.GeophysJ Int,110:501~517.
Kennett B L N,1991,IASPEI1991Seismological Tables.
Spencer.W.,1980,Relative epicenter determination using P-wave arrival-time differences.Bull.Seism.Soc.Am.70,pp171~183.
Gibowicz S J and Kijko A,1994,An Introductionto mining seismology,Academic Press,In.
Waldhauser,F.(U.S.Geological Survey);Ellsworth,W.L.,2000,ADouble-difference Earthquake location algorithm:Method andapplicationtothe Northern Hayward Fault,California.Bulletin of the Seismological Society of America,90(6):1353~1368.
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