Using GRACE Data To Inversion The Current Vertical Crustal Deformation Rate Of The Tibet Plateau

The upli ft and climate change of the Tibet Plateau(TP)have an important impact on the regional and global climate and environment.The formation and evolution of the East Asian monsoon system is closely related to the vertical deformation of the TP.Driven by it,the loess in the northwestern region began to deposit and Asia inland the continuous aridification of the TP,earthquakes,landslides,and debris flows frequently occur in the TP.Therefore,studying the related issues of the vertical deformation rate of the TP will help us understand the mechanism of global climate evolution and continental collision.Learning is of great significance.This paper mainly takes the TP and its surrounding areas as the research object,and uses satellite gravity data,hydrological models,lake data,glacier data and glacier equilibrium adjustment models as basic data,using spherical harmonic coefficient conversion,Gaussian filtering,decorrelation filtering,and least two Multiplication,vertical cuboid model and other methods are used to study the gravity change rate and vertical deformation rate of the study area.The main research contents and results are as follows:(1)Using the GRACE RL06 satellite gravity data from 2004 to 2015 to analyze the distribution characteristics of the rate of gravity change in the TP,it was found that the rate of gravity change in the TP and its surrounding areas showed an uneven distribution:in the Indian plate The gravity within the TP,the Sichuan Basin and the Burma plate shows an increasing trend,while the Tianshan,Himalayas,and the North China plate are all areas where gravity decreases.The rate of gravity change in the southern Indian plate is about 0.32?Gal/a,the rate of gravity change in the TP is about 0.17?Gal/a,the rate of gravity change in the Sichuan Basin is about 0.1?Gal/a,and the rate of gravity change in the Myanmar plate is about 0.21?Gal/a.a.The rate of gravity change in the Himalayas at the junction of the Indian and TP is about-0.56?Gal/a,the rate of gravity change in the Tianshan area is about-0.3?Gal/a,and the rate of gravity change in the North China plate is about-0.1?Gal/a.(2)Assuming that the signals detected by GRACE only include terrestrial water storage and crustal tectonic movement,using hydrological models,lakes,glaciers,and glacier balance adjustments,etc.data,the distribution of the rate of gravity change caused by terrestrial water storage from 2004 to 2015 is calculated.And remove it from the rate of gravity change obtained from GRACE data to obtain the rate of gravity change caused by crustal tectonic movement.The results showed that the rate of gravity change in the southern part of the TP was negative,and the rate of gravity change in the northern part was positive.The rate of gravity change at the junction of the northern Indian plate and the TP was about-0.5?Gal/a;the Indian plate,the Burmese plate and the The rate of gravity change at the junction of the TP is-0.3?Gal/a;the rate of gravity change at the junction of the TP and the Tarim Basin is about 0.35?Gal/a;the rate of gravity change in other regions is relatively small,the Tianshan area is about-0.12?Gal/a,Sichuan Basin is about 0.1?Gal/a.(3)It is assumed that the obtained crustal tectonic movement signal is only caused by the vertical deformation of the crustal,and does not include the signal caused by the horizontal crustal movement.Therefore,the relationship between the vertical movement of the vertical cuboid and the change of gravity is used to inverse the distribution of the vertical crustal deformation rate in the study area.The results of the study show that the vertical velocity distribution of the crust of the TP is uneven,which is represented by the Gangdise-Tanggula Mountain-Xianshuihe fault zone as the boundary,and the velocity difference between the two sides is large.Located to the south of the boundary,the average uplift rate of the region along the Himalayan nappe tectonic belt is 3.2mm/a.The uplift rates of the Indian plate on the west and the Myanmar plate on the east are 4.3mm/a and 3mm/a,respectively.The uplift rate of the area between the two plates is 1.2mm/a;north of the boundary,except for the Tianshan area and the North China plate,which have uplift rates of lmm/a,the uplift phenomenon of other areas is not obvious,and the rate is 0mm/a.The study found that there are two uplift rate gradient belts that both pass through the normal fault zone.One is from Kathmandu to the Tarim Basin,which happens to pass through the normal fault zone inside the TP,and the other is from the Naga Mountain to the Sichuan Basin.It happened to pass through the Dali normal fault zone.The results of this article provide some theoretical support for the study of scientific issues such as the uplift of the TP and help to understand the mechanism and process of continental plate collision.