利用海底地震仪和陆地固定台站记录联合研究2016年6月18日福建漳浦海域M_S3.3级地震震源参数
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摘要
本文利用海底地震仪(OBS)观测到的2016年6月18日漳浦海域M_S 3.3级地震波形,结合陆地固定台网记录,采用NonLinLoc方法对该地震进行了重定位,结果与福建台网定位结果较为一致.采用两种不同方法研究了震源机制解,P波初动极性方法确定了该次地震的共轭断层面解的走向/倾角/滑动角为91/85/-176或0/87/-5,是发生在滨海断裂带附近九龙江断裂沿线上的一个走滑型地震,而陆地台站记录的波形拟合反演结果得到的断层面解为179/79/30和83/61/167.为了评估OBS对震源参数反演的贡献,利用自举法(Bootstraping)评估了单独使用陆地台站记录和联合反演得到的定位和断层面解的方差,结果表明OBS数据的加入明显减小了地震水平位置的方差,而由于该次地震的机制解特性,OBS数据对机制解反演结果的改善程度较为有限.综上,OBS可以有效记录到海域地震信号,并用于地震定位、机制解等研究中,对陆地台网形成了较好的补充.
We relocated the M_S 3.3 earthquake in the Zhangpu area, Fujian on June 18, 2016 with the pickings on Ocean Bottom Seismometers(OBS) and inland stations. The relocated result is consistent with the result of Fujian seismic network center. Two methods are used to study the focal mechanism. Applying P wave first motion method, we obtain the fault plane solution of the earthquake is 91/85/-176. According to the result we conside the earthquake is a strike-slip earthquake that occur nearby the Jiulongjiang fault. At the same time, the fault plane solutions are 179/79/30 and 83/61/167 from the waveform fitting inversion. In order to evaluate the constribution of OBS, we using the Bootstraping method obtain the variance of location and fault plane soulutions from the only land station records and joint inversion. The results show that the addition of OBS data significantly reduces the varinance of seismic level position. However, because of the mechanism characteristics, OBS data is limited to improve the result of facal mechanism. In summary, OBS can effectively record the seismic signals in the sea area, and apply in the earthquake location, mechanism solution and other research. The OBS date can complement the lack of land network data.
We relocated the M_S 3.3 earthquake in the Zhangpu area, Fujian on June 18, 2016 with the pickings on Ocean Bottom Seismometers(OBS) and inland stations. The relocated result is consistent with the result of Fujian seismic network center. Two methods are used to study the focal mechanism. Applying P wave first motion method, we obtain the fault plane solution of the earthquake is 91/85/-176. According to the result we conside the earthquake is a strike-slip earthquake that occur nearby the Jiulongjiang fault. At the same time, the fault plane solutions are 179/79/30 and 83/61/167 from the waveform fitting inversion. In order to evaluate the constribution of OBS, we using the Bootstraping method obtain the variance of location and fault plane soulutions from the only land station records and joint inversion. The results show that the addition of OBS data significantly reduces the varinance of seismic level position. However, because of the mechanism characteristics, OBS data is limited to improve the result of facal mechanism. In summary, OBS can effectively record the seismic signals in the sea area, and apply in the earthquake location, mechanism solution and other research. The OBS date can complement the lack of land network data.
引文
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Tichelaar B W,Ruff L J. 1989. How good are our best models? Jackknifing,bootstrapping,and earthquake depth [J]. Eos,Transactions American Geophysical Union,70(20): 593- 606.
Xie X L,Sun J L,Kang Y,et al. 2015. Development of Offshore Ocean Bottom Seismometer to Promote the Accuracy of Coastal Earthquakes Relocation-A ML 2.8 Earthquake in the Open Sea of Nanao [J]. South china journal of seismology (in Chinese),35(1): 21-29.谢小玲,孙金龙,康英,等. 2015. 海底地震仪对海上地震定位精度的提升作用-以南澳外海域ML 2.8级地震为例[J]. 华南地震,35(1): 21-29.
Xu Z D. 2006. On 1604 M 8.0 Quanzhou earthquake in Fujian province [J]. Journal of Geodesy and Geodynamics (in Chinese),26(3): 78-83.许振栋. 2006. 1604年泉州海外8级地震研究[J]. 大地测量与地球动力学,26(3): 78-83.
Zeng X F,Luo Y,Han L B,et al. 2013. The Lushan MS 7.0 earthquake on 20 April 2013 A high-angle thrust event [J]. Chinese J. Geophys. (in Chinese),56(4): 1418-1424,doi: 10.6038/cjg20130437.曾祥方,罗艳,韩立波,等. 2013. 2013年4月20日四川芦山 MS 7.0地震: 一个高角度逆冲地震[J]. 地球物理学报,56(4): 1418-1424,doi: 10.6038/cjg20130437.
Zhao L S,Helmberger D V. 1994. Source estimation from broadband regional seismograms [J]. Bulletin of the Seismological Society of America,84(1): 91-104.
Zhong J M. 2009. Stress analysis on Binhai fault in Fujian coastal sea area [J]. Seismological and Geomagnetic Observation and Research (in Chinese),30(5): 14-19.钟继茂. 2009. 福建近岸海域滨海断裂的应力分析[J]. 地震地磁观测与研究,30(5): 14-19.
Zhu L,Helmberger D V. 1996. Advancement in source estimation techniques using broadband regional seismograms [J]. Bulletin of the Seismological Society of America,86(5): 1634-1641.
丁学仁,吴长江. 1999. 福建及其沿海地区中强以上地震的震源机制研究[J]. 地壳形变与地震,19(1): 95-97.
Lin S J,Ding X R,Chen W W,et al. 2009. Research on Focal Mechanism Solutions and Tectonic Stress Field in Fujian Region [J]. Jouranl of Geodesy and Geodyanamics (in Chinese),29(5): 27-32 林松建,丁学仁,陈为伟,等. 2009. 福建地区震源机制解与现代构造应力场研究[J]. 大地测量与地球动力学,29(5): 27-32.
Lomax A,Virieux J,Volant P,et al. 2000. Probabilistic Earthquake Location in 3D and Layered Models [J]. Advances in Seismic Event Location,101-134.
Lü H J. 2000. Background of seismotectonics of major earthquakes in the sea area south-east of Jinmen [J]. Seismology and Geology (in Chinese),22(2): 104-110.吕浩江. 2000. 金门东南海域中强地震活动区的地震构造背景[J]. 地震地质,22(2): 104-110.
Qiu Y,Jin X,Cai H T,et al. 2014. 1-D crust velocity structure in Fujian region using artificial earthquake [J]. Earthquake Engineering and Engineering Dynamics (in Chinese),34(S1): 1071-1076.邱毅,金星,蔡辉腾,等. 2014. 利用人工地震研究福建地壳一维速度结构[J]. 地震工程与工程振动,34(S1): 1071-1076.
Qiu Y,Zheng S H,Bao T,et al. 2013. Focal Mechanism Soulutions of Moderate Earthquakes in Fujian as Determined by Broadband Digital Data [J]. Earthquake (in Chinese),33(1): 65-73.邱毅,郑斯华,鲍挺,等. 2013. 利用地震台网宽频带地震记录计算福建中等强度地震的震源机制解[J]. 地震,33(1): 65-73.
Stachnik J C,Sheehan A F,Zietlow D W,et al. 2012. Determination of New Zealand ocean bottom seismometer orientation via Rayleigh-wave polarization [J]. Seismological Research Letters,83(4): 704-713.
Tichelaar B W,Ruff L J. 1989. How good are our best models? Jackknifing,bootstrapping,and earthquake depth [J]. Eos,Transactions American Geophysical Union,70(20): 593- 606.
Xie X L,Sun J L,Kang Y,et al. 2015. Development of Offshore Ocean Bottom Seismometer to Promote the Accuracy of Coastal Earthquakes Relocation-A ML 2.8 Earthquake in the Open Sea of Nanao [J]. South china journal of seismology (in Chinese),35(1): 21-29.谢小玲,孙金龙,康英,等. 2015. 海底地震仪对海上地震定位精度的提升作用-以南澳外海域ML 2.8级地震为例[J]. 华南地震,35(1): 21-29.
Xu Z D. 2006. On 1604 M 8.0 Quanzhou earthquake in Fujian province [J]. Journal of Geodesy and Geodynamics (in Chinese),26(3): 78-83.许振栋. 2006. 1604年泉州海外8级地震研究[J]. 大地测量与地球动力学,26(3): 78-83.
Zeng X F,Luo Y,Han L B,et al. 2013. The Lushan MS 7.0 earthquake on 20 April 2013 A high-angle thrust event [J]. Chinese J. Geophys. (in Chinese),56(4): 1418-1424,doi: 10.6038/cjg20130437.曾祥方,罗艳,韩立波,等. 2013. 2013年4月20日四川芦山 MS 7.0地震: 一个高角度逆冲地震[J]. 地球物理学报,56(4): 1418-1424,doi: 10.6038/cjg20130437.
Zhao L S,Helmberger D V. 1994. Source estimation from broadband regional seismograms [J]. Bulletin of the Seismological Society of America,84(1): 91-104.
Zhong J M. 2009. Stress analysis on Binhai fault in Fujian coastal sea area [J]. Seismological and Geomagnetic Observation and Research (in Chinese),30(5): 14-19.钟继茂. 2009. 福建近岸海域滨海断裂的应力分析[J]. 地震地磁观测与研究,30(5): 14-19.
Zhu L,Helmberger D V. 1996. Advancement in source estimation techniques using broadband regional seismograms [J]. Bulletin of the Seismological Society of America,86(5): 1634-1641.
丁学仁,吴长江. 1999. 福建及其沿海地区中强以上地震的震源机制研究[J]. 地壳形变与地震,19(1): 95-97.