基于欧拉反褶积方法计算川滇交界重力变化场源特征  

Based on the euler deconvolution technique to determine the field source characteristics of gravity Variation in the boundary of Sichuan and Yunnan

作　　者：高倩[1] 陈石[2] 

机构地区：[1]长安大学地球科学与资源学院,西安710064 [2]中国地震局地球物理研究所,北京100081

出　　处：《地球物理学进展》2015年第2期503-509,共7页Progress in Geophysics

基　　金：地震行业科研专项(201208004);中国地震局地球物理研究所基本科研业务专项(DQJB12C03);国家自然科学基金青年项目(41104046);中国地震局"云南鲁甸6.5级地震专题研究"项目联合资助

摘　　要：本文以川滇地区2012-2014年来的多期流动重力观测网络数据为基础,采用欧拉反褶积方法对引起重力变化的场源深度和空间分布规律进行了反演和解释.本文通过构建理论模型。得到了最优的反演参数,并对实际数据进行了计算和分析.结果表明:选择构造指数(SI)为1时适合对流动重力数据进行反演.实际资料的反演结果显示在2012-2014年间的重力变化场源位置更集中于垂直于昭通断裂的北西向分布,场源深度分布在30±10 km范围,形态与鲁甸地震发震构造位置相似.这可能与2014年8月3日鲁甸M_S 6.5地震前的中上地壳的深部应力场变化相关.依据本文研究结果和方法,可以开展由场至源的定量研究,为流动重力变化信号的反演和解释提供一条新思路.In this paper, based on the mobile gravity observed data from 2012 to 2014, we employed the Euler deconvoiution method to determine the parameters of field source that generated the observed gravity variation. We also got the optimal parameters for inversion by means of the model forward approach. On the basis of the well-known model, we give the analysis and explanations to the observed dataset. The results show the Structural Index（SI） that equal 1 is suitable to inverse the gravity variation datum. For the gravity variation of 2012- 2014, the inversed results indicated that the positions the depths of anomaly sources spread over the NW direction, perpendicular to ZhaoTong fault and mainly converged to the 30 ±10 km. The direction of field sources distribution is similar to the structure of Ludian Ms 6. 5 earthquake. We infer to this feature which related to the variations of stress filed in the upper and middle crust before the Ludian Ms 6. 5 on Aug. 3th, 2014. Our study and results were capable to carry out some quantitative research related to the field source and may shed new light on the interpretations on the gravity variation.

关 键 词：欧拉反褶积 位场反演 重力场变化 构造指数 川滇交界 鲁甸M_s 6.5地震 

分 类 号：P312[天文地球—固体地球物理学] P315[天文地球—地球物理学]