用格点尝试法求解P波初动震源机制解及解的质量评价

doi:10.3969/j.issn.0001-5733.2009.05.030

CORC > 北京大学 > 地球与空间科学学院

	用格点尝试法求解P波初动震源机制解及解的质量评价; P-wave first-motion focal mechanism solutions and their quality evaluation
	俞春泉 ; 陶开 ; 崔效锋 ; 胡幸平 ; 宁杰远
刊名	地球物理学报
	2009
关键词	震源机制解 P波初动网格搜索法 Focal mechanism solution P-wave first motion Grid search method
DOI	10.3969/j.issn.0001-5733.2009.05.030
英文摘要	P波初动符号物理图像明确,是稳定的地震波信息.在资料充分时,可以较好地确定震源机制解.网格搜索法是目前流行的利用P波初动符号求解地震震源机制解的方法.不过,在实际观测资料不充分时,虽然较迭代算法优越,但网格搜索法依然有较大的不确定性.到目前为止,人们还没有找到合理的解决方案,极大地制约了这一类方法的应用.针对这一现状,本文在许忠淮提出的格点尝试法的基础上对网格搜索法进行了几个方面的改进.首先,采用新的加权方法计算加权矛盾比:权重因子包括反映初动符号质量的权重以体现资料质量的影响;不包括反映观测点与节面距离的权重以避免因节面附近资料权重的双重减小带来的系统偏差;通过减小震源球上密集资料点的权重以...; P-wave first motion, an unambiguous physical quantity, is a kind of steady seismic information. When enough data were available, it could be used to ideally determine focal mechanism solutions. The most popular method for employing P-wave first motion to determine focal mechanism solutions is the grid search method. However, when applied to earthquakes with few data points, grid search method still has great uncertainty, although it is believed to be better than the iterative method. By now, no satisfactory settlement has been found, which greatly restricts the application of this method. In this paper, we focus on the improvement of former grid search methods. Firstly, possible solutions are selected by weighted inconsistency ratio. Here, the weighting scheme retains the data-quality weighting factor so as to consider the influence of data quality, omits the weighting factor reflecting the distance between data points and nodal planes for avoiding over-reducing the weights of the observations near nodal planes, and adds another weighting factor which gives more power to sparse data points on the focal sphere for partly canceling out the influence of uneven distribution of the employed data points. Meanwhile, we divide the focal sphere into several roughly equal-square areas, which prevent deviation from real mean solution by artificial concentration of test solutions. We improve our inversion quality by employing jackknife technique, which enlarges the solution set by adding those possible solutions for one observation being ignored. This technique, along with clustering analysis, not only increases the possibility of finding out true solutions, but also makes us comprehend the quality of focal mechanism solutions unambiguously. Finally, we provide a new scheme for evaluating the quality of focal mechanism solutions based on the dispersion of selected solutions as well as the minimum weighted inconsistency ratio.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000266542700030&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); 10; 05; 1402-1411; 52
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/50184]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	俞春泉,陶开,崔效锋,等. 用格点尝试法求解P波初动震源机制解及解的质量评价, P-wave first-motion focal mechanism solutions and their quality evaluation[J]. 地球物理学报,2009.
APA	俞春泉,陶开,崔效锋,胡幸平,&宁杰远.(2009).用格点尝试法求解P波初动震源机制解及解的质量评价.地球物理学报.
MLA	俞春泉,et al."用格点尝试法求解P波初动震源机制解及解的质量评价".地球物理学报 (2009).