The Analysis of the Abnormal Characteristics of GPS Data before the 2013 Minxian-Zhangxian M S6.6 Earthquake

2018 2nd International Workshop on Renewable Energy and Development

能源学;经济学

Ma, H.P.^1 ; Feng, J.G.^1 ; Wu, S.Y.^1 ; Xu, R.^1 ; Huang, Y.L.^2 ; Li, N.^1 ; Wang, Q.^1

Lanzhou Institute of Seismology, China Earthquake Administration (CEA), Lanzhou

730000, China^1

Lanzhou Lanshi Energy Equipment Engineering Institute Co., Ltd., Lanzhou

730314, China^2

关键词: Abnormal characteristics;    Crustal deformations;    Earthquake events;    Extrusion deformation;    GPS velocity field;    Movement characteristics;    Strain accumulations;    Stress accumulation;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/153/6/062044/pdf
DOI  :  10.1088/1755-1315/153/6/062044

来源: IOP

【 摘 要 】

To study the movement characteristics of crustal deformation around the epicenter before the M s6.6 earthquake in Minxian-Zhangxian in 2013, the paper analyzes the GPS velocity field, the baseline time series between stations and the time series of the epicentral region strain, and then discusses the characteristics of the crustal deformation before the earthquake. It is shown from the results that the Lintan-Tanchang fault and the Northern Xiqinling fault are in the inner circle of the clockwise vortex, which have obvious stress accumulation. Among the two velocity fields in 2004-2007 and 2009-2011, there are significant differences in the direction and amplitude of the movement around the Lintan-Tanchang fault, which may cause the risk of earthquake events. The baseline time series reflect the strain accumulation in NE side of Lintan-Tanchang thrust fault with NE-trending was quite high before the earthquake, and the velocity of the SW side was accelerating, which might be the main cause of the earthquake. Since 2013, the extrusion deformation of EW direction and plane shrinkage rate near the epicenter had shown an obvious weakening tendency, as well as the left-lateral shear of NW direction of the causative fault. The evidence of deformation loss before the earthquake was significant and the accumulation of strain was relatively obvious.