摘要
破裂过程快速反演是目前快速获取地震灾害特征的主要手段之一,是震后应急工作的重要内容.近十年来基于远震资料开展的手动快速反演工作取得了长足进步,但在响应时间方面存在固有的局限,阻碍了反演效率的持续提升.我们根据新近发展的IDS(Iterative Deconvolution and Stacking)自动反演方法,尝试反演近场强震动资料确定破裂过程,探讨破裂过程反演自动化的可行性.对近几年国内发生的强震——包括2013年芦山MW6.6地震、2016年青海门源MW5.9地震和2016年新疆阿克陶MW6.6地震——的应用结果表明,采用IDS方法反演强震数据可以得到稳定可靠的破裂模型,且反演计算时间都控制在几十秒内.此外,以2008年汶川MW7.9地震为例,测试了不同子断层尺度、截止频率和地壳速度结构模型对反演结果的影响,发现滑动分布主要特征不强烈依赖于反演参数和地壳模型,证实了自动反演的稳定性和很强的适应能力.这一研究表明,基于强震动资料的自动反演可能是破裂过程快速反演的主要发展方向.特别地,在未来强震动台网持续发展、强震动数据的质量和共享速度都得到进一步提高之后,这一工作可望纳入到地震参数的常规自动测定工作中,为震后应急和海域地震的海啸预警提供急需的震源模型.
Rapid inversion of earthquake rupture process is one of the main approaches to estimate the disaster characteristics,and is also a major work in post-earthquake emergency responses.In the last decade,the fast inversion of teleseismic data has made great progress,but its inherent limitation in response time hinders the continuous improvement in efficiency.With the newly developed automatic IDS(Iterative Deconvolution and Stacking)method,we tried inverting the strong motion data for rupture process,and investigated the feasibility of automatic inversion.The applications to recent strong earthquakes in China(i.e.,the 2013 Lushan M W6.6 earthquake,the 2016 Menyuan M W5.9 earthquake and the 2016 Aketao M W6.6 earthquake)suggest that strong motion data inversion can retrieve the rupture model stably and reliably.The time consumed is only about dozens of seconds.In addition,taking the case of 2008 Wenchuan M W7.9 earthquake,we checked the impacts of different sub-fault sizes,the cut-off frequencies of low-pass filters,and the crust velocity structures on inversion results.It was found that the main characteristics of slip model are almost independent of these factors,implying a strong adaptability of the automatic inversion with near-field strong motion data.This research indicates that the automatic inversion with the strong motion data may be the future direction of rapid finite-fault inversion.In particular,with the continuous development of strong motion network,and the improvements in the data quality and the data transfer speed,the automatic inversion could be incorporated into the routine determination of source parameters.It can provide the most urgent rupture model for earthquake emergency responses and tsunami early warnings.
作者
郑绪君
张勇
马强
汪荣江
ZHENG XuJun;ZHANG Yong;MA Qiang;WANG RongJiang(School of Earth and Space Sciences,Peking University,Beijing 100871,China;Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;Helmholtz Centre Potsdam,GFZ German Research Centre for Geosciences,D-14473 Potsdam,Germany)
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第10期4021-4036,共16页
Chinese Journal of Geophysics
基金
国家自然科学基金(41574035和41822401)资助
关键词
IDS方法
破裂过程
地震应急响应
强震动数据
IDS method
Rupture processes
Earthquake emergency responses
Near-field strong motion data
