In this study, the relative gravity data(2012 e2015), GPS data-derived horizontal deformation(2011 e2014) and the background vertical deformation from the leveling measurements(1970 e2011) in the northeastern margin o...In this study, the relative gravity data(2012 e2015), GPS data-derived horizontal deformation(2011 e2014) and the background vertical deformation from the leveling measurements(1970 e2011) in the northeastern margin of Tibetan Plateau were processed to systematically analysis the mechanism of temporalespatial patterns and the relationship with Menyuan Ms6.4 earthquake. It can be summarized in the following: 1) The regional gravity changes, the GPS and the vertical deformational showed an intense spatial relationship: the gravity increased along with the direction of horizontal movement, and decreased with the crustal uplift and vice versa, which reflected the inherited characteristics of geotectonic activities. 2) The crustal deformations were closely related to the active faults. The contour lines of gravity changes and vertical deformation were generally along with the Qilian-Haiyuan fault(strike is NWW), and the crustal horizontal deformation showed left-lateral strike slip motion near the Qilian-Haiyuan fault. 3) Menyuan Ms6.4 earthquake occurred in the high negative gravity variation area and a high gradient formed in regions, positive and negative variation of gravity amount to 110 m Gal.Specifically, a borderline of positive and negative gravity located in the south of epicenter along the north edge of Qilianshan fault and Lenglongling fault, as well as the vertical and/or horizontal deformation is intensely. The extrusion deformation, surface compression rate and gravity changes were obvious near the epicenter of 2016 Menyuan Earthquake.展开更多
基金funded by the directional earthquake tracking task offered by China Earthquake Administration (2017010203)the National Natural Science Foundation of China (No. 41274083)
文摘In this study, the relative gravity data(2012 e2015), GPS data-derived horizontal deformation(2011 e2014) and the background vertical deformation from the leveling measurements(1970 e2011) in the northeastern margin of Tibetan Plateau were processed to systematically analysis the mechanism of temporalespatial patterns and the relationship with Menyuan Ms6.4 earthquake. It can be summarized in the following: 1) The regional gravity changes, the GPS and the vertical deformational showed an intense spatial relationship: the gravity increased along with the direction of horizontal movement, and decreased with the crustal uplift and vice versa, which reflected the inherited characteristics of geotectonic activities. 2) The crustal deformations were closely related to the active faults. The contour lines of gravity changes and vertical deformation were generally along with the Qilian-Haiyuan fault(strike is NWW), and the crustal horizontal deformation showed left-lateral strike slip motion near the Qilian-Haiyuan fault. 3) Menyuan Ms6.4 earthquake occurred in the high negative gravity variation area and a high gradient formed in regions, positive and negative variation of gravity amount to 110 m Gal.Specifically, a borderline of positive and negative gravity located in the south of epicenter along the north edge of Qilianshan fault and Lenglongling fault, as well as the vertical and/or horizontal deformation is intensely. The extrusion deformation, surface compression rate and gravity changes were obvious near the epicenter of 2016 Menyuan Earthquake.
