To better understand the mechanism of the Mw6.3 L'Aquila(Central Italy) earthquake occurred in 2009,global positioning system(GPS) and interferometric synthetic aperture radar(InSAR) data were used to derive the c...To better understand the mechanism of the Mw6.3 L'Aquila(Central Italy) earthquake occurred in 2009,global positioning system(GPS) and interferometric synthetic aperture radar(InSAR) data were used to derive the coseismic slip distribution of the earthquake fault.Firstly,based on the homogeneous elastic half-space model,the fault geometric parameters were solved by the genetic algorithm.The best fitting model shows that the fault is a 13.7 km×14.1 km rectangular fault,in 139.3° strike direction and 50.2° southwest-dipping.Secondly,fixing the optimal fault geometric parameters,the fault plane was extended and discretized into 16×16 patches,each with a size of 1 km×1 km,and the non-uniform slip distribution of the fault was inverted by the steepest descent method with an appropriate smoothing ratio based on the layered crustal structure model.The preferred solution shows that the fault is mainly a normal fault with slight right-lateral strike slip,the maximum slip of 1.01 m is located in the depth of 8.28 km,the average rake is -100.9°,and the total geodetic moment is about 3.34×1018 N·m(Mw 6.28).The results are much closer than previous studies in comparison with the seismological estimation.These demonstrate that the coseismic fault slip distribution of the L'Aquila earthquake inverted by the crustal model considering layered characters is reliable.展开更多
地震矩张量反演的技术已成功地应用于很多地震事件,以确定震源参数,研究震源破裂的过程。文章用Kikuchi和Kanamori提出的远震体波反演技术和算法,利用IRIS(Incorporated Research Institutions of Seismology)数据中心记录的宽频带数字...地震矩张量反演的技术已成功地应用于很多地震事件,以确定震源参数,研究震源破裂的过程。文章用Kikuchi和Kanamori提出的远震体波反演技术和算法,利用IRIS(Incorporated Research Institutions of Seismology)数据中心记录的宽频带数字地震波形资料(震中距范围30°-90°)和当地地壳速度结构模型,反演了2008年10月6日西藏当雄地震,地震观测波形与反演得到的波形吻合比较好,确定了该地震的源机制、地震矩张量解、震源深度等参数。文章提出,这次地震是正断层为主的南北走向的浅震。展开更多
By using an offshore large volume air-gun seismic source, onshore seismic stations( including mobile stations and permanent stations) and ocean bottom seismometers,a deep seismic exploration experiment was carried out...By using an offshore large volume air-gun seismic source, onshore seismic stations( including mobile stations and permanent stations) and ocean bottom seismometers,a deep seismic exploration experiment was carried out for the first time in the Taiwan Straits. Results show that seismic stations can receive seismic signals from the air-gun arrays of the "YANPING Ⅱ"scientific investigation ship from as far as 280 km away.Tens of thousands of high quality seismic data items were obtained successfully and different types of P-wave seismic phases were identified. A one-dimensional crustal structure model of the survey profile HX9 shows that the crustal structure,which is reflected by Pc and Pm P reflection waves from two velocity discontinuities and basement refraction wave( Pg) constitutes the basic characteristic of the crustal structure in this region. The depths of Conrad discontinuity and Moho discontinuity are respectively16. 0km- 17. 5km and 28. 0km- 29. 5km.展开更多
基金supported by the National Natural Science Foundation of China (Grant 20930140)the Chinese Academy of Sciences and the sponsors of the Centre for Reservoir Geophysics of the Imperial College
基金Projects(40974006,40774003) supported by the National Natural Science Foundation of ChinaProject(NCET-08-0570) supported by the Program for New Century Excellent Talents in Chinese Universities+2 种基金Projects(2011JQ001,2009QZZD004) supported by the Fundamental Research Funds for the Central Universities in ChinaProjects(09K005,09K006) supported by the Key Laboratory for Precise Engineering Surveying & Hazard Monitoring of Hunan Province,ChinaProject(1343-74334000023) supported by the Graduate DegreeThesis Innovation Foundation of Central South University,China
文摘To better understand the mechanism of the Mw6.3 L'Aquila(Central Italy) earthquake occurred in 2009,global positioning system(GPS) and interferometric synthetic aperture radar(InSAR) data were used to derive the coseismic slip distribution of the earthquake fault.Firstly,based on the homogeneous elastic half-space model,the fault geometric parameters were solved by the genetic algorithm.The best fitting model shows that the fault is a 13.7 km×14.1 km rectangular fault,in 139.3° strike direction and 50.2° southwest-dipping.Secondly,fixing the optimal fault geometric parameters,the fault plane was extended and discretized into 16×16 patches,each with a size of 1 km×1 km,and the non-uniform slip distribution of the fault was inverted by the steepest descent method with an appropriate smoothing ratio based on the layered crustal structure model.The preferred solution shows that the fault is mainly a normal fault with slight right-lateral strike slip,the maximum slip of 1.01 m is located in the depth of 8.28 km,the average rake is -100.9°,and the total geodetic moment is about 3.34×1018 N·m(Mw 6.28).The results are much closer than previous studies in comparison with the seismological estimation.These demonstrate that the coseismic fault slip distribution of the L'Aquila earthquake inverted by the crustal model considering layered characters is reliable.
文摘地震矩张量反演的技术已成功地应用于很多地震事件,以确定震源参数,研究震源破裂的过程。文章用Kikuchi和Kanamori提出的远震体波反演技术和算法,利用IRIS(Incorporated Research Institutions of Seismology)数据中心记录的宽频带数字地震波形资料(震中距范围30°-90°)和当地地壳速度结构模型,反演了2008年10月6日西藏当雄地震,地震观测波形与反演得到的波形吻合比较好,确定了该地震的源机制、地震矩张量解、震源深度等参数。文章提出,这次地震是正断层为主的南北走向的浅震。
基金funded by Youth Science and Technology Fund of Earthquake Administration of Fujian Province,China(Y201407)
文摘By using an offshore large volume air-gun seismic source, onshore seismic stations( including mobile stations and permanent stations) and ocean bottom seismometers,a deep seismic exploration experiment was carried out for the first time in the Taiwan Straits. Results show that seismic stations can receive seismic signals from the air-gun arrays of the "YANPING Ⅱ"scientific investigation ship from as far as 280 km away.Tens of thousands of high quality seismic data items were obtained successfully and different types of P-wave seismic phases were identified. A one-dimensional crustal structure model of the survey profile HX9 shows that the crustal structure,which is reflected by Pc and Pm P reflection waves from two velocity discontinuities and basement refraction wave( Pg) constitutes the basic characteristic of the crustal structure in this region. The depths of Conrad discontinuity and Moho discontinuity are respectively16. 0km- 17. 5km and 28. 0km- 29. 5km.
