利用重复地震观测粤闽交界地区地壳介质变化
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摘要
利用粤闽两省数字化地震台网2007年6月～2010年5月的走时及波形记录对南澳地区ML≥1地震用双差法重新进行定位,根据定位结果挑选重复地震丛,并研究地震丛的P波走时经伪弯曲射线追踪技术及波形互相关校正后的走时差变化。经上述处理后,汕头台、潮州台记录的南澳地区地震的P波走时差在2008年6～8月间出现负异常,经与地震活动性及形变观测资料对比分析,认为该时段的负异常反映了区域地壳介质速度有所上升。
In this paper,we relocated earthquakes sequences occurring in the border area between Guangdong and Fujian Provinces from June,2007 to May,2010 using the double-difference location algorithm.During relocating,the cross correlation of waveform data and seismic wave travel time were used.The repeating earthquakes were selected according to the relocated result.We normalized the position of repeating earthquakes by using ray tracing.The accuracy of P-wave travel time can be improved by using ray tracing and cross correlation of waveform data,and the crustal media variation can be measured.According the calculation routine,P-wave travel time difference of the Shantou and Chaozhou seismic station retained negative anomaly from June to August,2008.After contrasting with seismic activity and crustal deformation of the Shantou and Chaozhou seismic station,we believe that the negative anomaly from June to August,2008 indicated the short-term velocity variation of crustal media.
In this paper,we relocated earthquakes sequences occurring in the border area between Guangdong and Fujian Provinces from June,2007 to May,2010 using the double-difference location algorithm.During relocating,the cross correlation of waveform data and seismic wave travel time were used.The repeating earthquakes were selected according to the relocated result.We normalized the position of repeating earthquakes by using ray tracing.The accuracy of P-wave travel time can be improved by using ray tracing and cross correlation of waveform data,and the crustal media variation can be measured.According the calculation routine,P-wave travel time difference of the Shantou and Chaozhou seismic station retained negative anomaly from June to August,2008.After contrasting with seismic activity and crustal deformation of the Shantou and Chaozhou seismic station,we believe that the negative anomaly from June to August,2008 indicated the short-term velocity variation of crustal media.
引文
陈翰林、赵翠萍、修济刚等,2009,龙滩水库地震精定位及活动特征研究,地球物理学报,52(8),2035～2043。
黄媛,2008,结合波形互相关技术的双差算法在地震定位中的应用探讨,国际地震动态,(4),29～34。
王新岭、刘杰、张国民等,2005,姚安地震序列与永胜地震序列的高精度定位,中国地震,21(3),386～397。
闻则刚、杨马陵、叶秀薇等,2005,广东省东部地区的S波速度结构,西北地震学报,27(2),154～157。
杨智娴、陈运泰,2004,用双差地震定位法再次精确测定1998年张北-尚义地震序列的震源参数,地震学报,26(2),115～120。
杨智娴、陈运泰、郑月军等,2003,双差地震定位法在我国中西部地区地震精确定位中的应用,中国科学(D辑),33(增刊),129～134。
姚伯初、曾维军、D.E.Hayes等,1994,中美合作调研南海地质专报GMSCS,武汉:中国地质大学出版社。
叶秀薇、闻则刚、刘锦等,2008,利用重复地震研究广东阳江地区地壳介质变化,地震,28(4),103～111。
张天中、武巴特尔、黄媛等,2007,近台资料对近震相对定位算法的影响,地球物理学报,50(4),1123～1130。
郑圻森、朱介寿、曹家敏等,2004,华南地区岩石圈地壳速度结构数据处理,物探化探计算技术,26(2),97～100。
郑圻森、朱介寿、宣瑞卿等,2003,华南地区地壳速度结构分析,沉积与特提斯地质,23(12),9～13。
周龙泉、刘桂萍、马宏生等,2007,利用重复地震观测地壳介质变化,地震,27(3),1～9。
Poupinet G,Ellsworth W L,Frechet J,1984,Monitoring velocity variations in the crust using earthquake doublets:an applicationto the Calaveras Fault,California,J Geophys Res,89(B7),5719～5731.
Um J,Thurber C H,1987,A fast algorithm for two-point seismic ray tracing,Bull Seism Soc Amer,77(3),972～986.
Waldhauser F,Ellaworth W L,2000,A double-difference earthquake location algorithm:Method and application to the NorthernHayward fault,California,Bull Seism Soc Amer,90(6),1353～1368.
黄媛,2008,结合波形互相关技术的双差算法在地震定位中的应用探讨,国际地震动态,(4),29～34。
王新岭、刘杰、张国民等,2005,姚安地震序列与永胜地震序列的高精度定位,中国地震,21(3),386～397。
闻则刚、杨马陵、叶秀薇等,2005,广东省东部地区的S波速度结构,西北地震学报,27(2),154～157。
杨智娴、陈运泰,2004,用双差地震定位法再次精确测定1998年张北-尚义地震序列的震源参数,地震学报,26(2),115～120。
杨智娴、陈运泰、郑月军等,2003,双差地震定位法在我国中西部地区地震精确定位中的应用,中国科学(D辑),33(增刊),129～134。
姚伯初、曾维军、D.E.Hayes等,1994,中美合作调研南海地质专报GMSCS,武汉:中国地质大学出版社。
叶秀薇、闻则刚、刘锦等,2008,利用重复地震研究广东阳江地区地壳介质变化,地震,28(4),103～111。
张天中、武巴特尔、黄媛等,2007,近台资料对近震相对定位算法的影响,地球物理学报,50(4),1123～1130。
郑圻森、朱介寿、曹家敏等,2004,华南地区岩石圈地壳速度结构数据处理,物探化探计算技术,26(2),97～100。
郑圻森、朱介寿、宣瑞卿等,2003,华南地区地壳速度结构分析,沉积与特提斯地质,23(12),9～13。
周龙泉、刘桂萍、马宏生等,2007,利用重复地震观测地壳介质变化,地震,27(3),1～9。
Poupinet G,Ellsworth W L,Frechet J,1984,Monitoring velocity variations in the crust using earthquake doublets:an applicationto the Calaveras Fault,California,J Geophys Res,89(B7),5719～5731.
Um J,Thurber C H,1987,A fast algorithm for two-point seismic ray tracing,Bull Seism Soc Amer,77(3),972～986.
Waldhauser F,Ellaworth W L,2000,A double-difference earthquake location algorithm:Method and application to the NorthernHayward fault,California,Bull Seism Soc Amer,90(6),1353～1368.
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