We compile the GOCE-only satellite model GOSG01S complete to spherical harmonic degree of 220 using Satellite Gravity Gradiometry （SGG） data and the Satellite-to-Satellite Tracking （SST） observations along the GOC...We compile the GOCE-only satellite model GOSG01S complete to spherical harmonic degree of 220 using Satellite Gravity Gradiometry （SGG） data and the Satellite-to-Satellite Tracking （SST） observations along the GOCE orbit based on applying a least-squares analysis. The diagonal components （Vxx, Vyy, Vzz） of the gravitational gradient tensor are used to form the system of observation equations with the band-pass ARMA filter. The point-wise acceleration observations （ax, ay, az） along the orbit are used to form the system of observation equations up to the maximum spherical harmonic degree/order 130. The analysis of spectral accuracy characteristics of the newly derived gravitational model GOSG01S and the existing models GOTIM04S, GODIR04S, GOSPW04S and JYY_GOCE02S based on their comparison with the ultrahigh degree model EIGEN-6C2 reveals a significant consistency at the spectral window approximately between 80 and 190 due to the same period SGG data used to compile these models. The GOCE related satellite gravity models GOSG01S, GOTIM05S, GODIR05S, GOTIM04S, GODIR04S, GOSPW04S, JYY_- GOCE02S, EIGEN-6C2 and EGM2008 are also validated by using GPS-leveling data in China and USA. According to the truncation at degree 200, the statistic results show that all GGMs have very similar differences at GPS-leveling points in USA, and all GOCE related gravity models have better performance than EGM2008 in China. This suggests that all these models provide much more information on the gravity field than EGM2008 in areas with low terrestrial gravity coverage. And STDs of height anomaly differences in China for the selected truncation degrees show that GOCE has improved the accuracy of the global models beyond degree 90 and the accuracies of the models improve from 24 cm to 16 cm. STDs of geoid height differences in USA show that GOSG01S model has best consistency comparing with GPSleveling data for the frequency band of the degree between 20 and 160.展开更多
A detailed knowledge of the thickness of the lithosphere in the North China craton（NCC） is important for understanding the significant tectonic reactivation of the craton in Mesozoic and Ce-nozoic.We achieve this go...A detailed knowledge of the thickness of the lithosphere in the North China craton（NCC） is important for understanding the significant tectonic reactivation of the craton in Mesozoic and Ce-nozoic.We achieve this goal by applying the newly proposed continuous wavelet transform theory to the Gravity Field Model（EGM 2008） data in the region.Distinct structural variations are identified in the scalogram image of profile Alxa-Datong（大同）-Qingdao（青岛）-Yellow Sea（profile ABC）,trans-versing the main units of NCC,which we interpret as mainly representing the Moho and lithosphere-asthenosphere boundary（LAB） undulations.The imaged LAB is as shallow as 60-70 km in the south-east basin and coastal areas and deepens to no more than 140 km in the northwest mountain ranges and continental interior.A rapid change of about 30 km in the LAB depth was detected at around the boundary between the Bohai（渤海） Bay basin（BBB） and the Taihang（太行） Mountains（TM）,roughly coincident with the distinct gravity decrease of more than 100 mGal that marks the North-South Grav-ity Lineament（NSGL） in the region.At last we present the gravity modeling work based on the spectral analysis results,incorporating with the observations on high-resolution seismic images and surface to-pography.The observed structural differences between the eastern and western NCC are likely associ-ated with different lithospheric tectonics across the NSGL.Combined with seismic tomography results and geochemical and petrological data,this sug-gests that complex modification of the litho-sphere probably accompanied significant litho-spheric thinning during the tectonic reactivation of the old craton.展开更多
Estimation of the zero-height geopotential value W_0^（LVD） for the CVD（China Vertical Datum） plays a fundamental role in the connection of traditional height reference systems into a global height system.Estimatio...Estimation of the zero-height geopotential value W_0^（LVD） for the CVD（China Vertical Datum） plays a fundamental role in the connection of traditional height reference systems into a global height system.Estimation the W_0^（LVD） of China is based on the computation of the mean geopotential offset between the value W_0= 62636856.0 m^2 s^（-2）, selected as reference in this study, and the unknown geopotential value W_0^（LVD）. This estimation is based on the combination of ellipsoidal heights, levelled heights（referring to the CVD）, and some physical parameters, such as geopotential values, gravity values, and geoid undulations.The geoid undulations derived from the GGM（Global Geopotential Models）. This combination is performed through three approaches： The first one is based on the theory of Molodensky, and the second one compares levelled heights and geopotential values derived from the GGMs, while the third one analyses the differences between GPS/Levelling and GGMs geoid undulations. The approaches are evaluated at 65 benchmarks（BMs） covered around Qingdao where the tide gauge is used to observe the local mean sea level of China. The results from three approaches are very similar. Furthermore, the W_0^（LVD）determined for the China local vertical datum was 62636852.9462 m^2 s^（-2）, indicates a bias of about3.0538 m^2/s^（-2） compared to the conventional value of 62636856.0 m^2 s^（-2）.展开更多
The Mohorovicic discontinuity(Moho)boundary separating the Earth’s crust and mantle reflects the evolutionary trajectory of the Earth’s crust,yielding crucial insights into crustal formation,tectonic evolution,and p...The Mohorovicic discontinuity(Moho)boundary separating the Earth’s crust and mantle reflects the evolutionary trajectory of the Earth’s crust,yielding crucial insights into crustal formation,tectonic evolution,and profound dynamic processes.However,the prevailing Moho models for China and its adjacent areas suffer from limited accuracy,owing to the irregular and sparse distribution of seismic data collection.In this study,we employ gravimetric data to derive Moho depth,and employ Bott’s regularization method,integrating gravity and seismic data to reconstruct the Moho structure with high precision in a three-dimensional framework across China and its adjacent areas.By optimizing gravity potential field separation and interface inversion techniques,we present a detailed and accurate zoning scheme for classifying China and its adjacent areas into 35 gradient belts,6 primary tectonic units,and 35 secondary tectonic units,based on the spatial distribution characteristics of the Moho discontinuity.Notably,our tectonic pattern division results surpass previous studies in terms of resolution,providing a wealth of tectonic information.Leveraging the Moho depth model of China and its adjacent areas,we discuss orogenic belts,sedimentary basins,fault systems,plate boundaries,and land-sea coupled tectonic patterns.We meticulously summarize the Moho depth distribution characteristics of each tectonic unit,while exploring the macrostructural framework and geological significance of the study area.Our findings highlight the close relationship between China and its adjacent areas Moho depth model and deep geodynamics,elucidating the tectonic evolution both between and within tectonic plates,as well as the tectonic effects induced by mantle dynamics.These insights have crucial implications for the study of deep geodynamics in China and its adjacent areas.展开更多
The latest geopotential model, EGM96, was employed to compute the free-air gravity anomaly, geoidal separation, the average density anomalies of the crust and the uppermost mantle, and the distribution pattern of the ...The latest geopotential model, EGM96, was employed to compute the free-air gravity anomaly, geoidal separation, the average density anomalies of the crust and the uppermost mantle, and the distribution pattern of the viscous stress exerted by mantle convection over Xinjiang and its neighboring areas. Based on these results and other data, we try to interpret the geodynamical features of the Tianshan orogen. Our research suggests that the Tianshan orogen is in a tectonic setting of compressive settling, driven by mantle convection. Under the effect of the compressive stress field, asymmetric in north-south direction, the Tianshan orogen upheaved quickly. The center of compressive stress field is in the south of the Tianshan, and the characteristic of stress field is favorable for the view point that the Tarim plat subducts beneath the Tianshan. The southern margin of the Juggar basin and the northern margin of the Tarim basin are two areas where the crust is of mass deficiency. We attribute the mass deficiency to the fact that the crust, in both the north and the south of the Tianshan is bent downwards under the compressive stress. Our research also indicates that the density distribution patterns in the deep of the eastern Tianshan are different from those in the middle and western Tianshan. It may be explained as the results from the east-west oriented distinction of the mantle convection.展开更多
基金financially supported by the National Key Basic Research Program of China(973 program,grant no.:2013CB733302,2013CB733301)the Major International(Regional) Joint Research Project(grant no.:41210006)+1 种基金DAAD Thematic Network Project(grant no.:57173947)the National Natural Science Foundation of China(grant No.41374022)
文摘We compile the GOCE-only satellite model GOSG01S complete to spherical harmonic degree of 220 using Satellite Gravity Gradiometry （SGG） data and the Satellite-to-Satellite Tracking （SST） observations along the GOCE orbit based on applying a least-squares analysis. The diagonal components （Vxx, Vyy, Vzz） of the gravitational gradient tensor are used to form the system of observation equations with the band-pass ARMA filter. The point-wise acceleration observations （ax, ay, az） along the orbit are used to form the system of observation equations up to the maximum spherical harmonic degree/order 130. The analysis of spectral accuracy characteristics of the newly derived gravitational model GOSG01S and the existing models GOTIM04S, GODIR04S, GOSPW04S and JYY_GOCE02S based on their comparison with the ultrahigh degree model EIGEN-6C2 reveals a significant consistency at the spectral window approximately between 80 and 190 due to the same period SGG data used to compile these models. The GOCE related satellite gravity models GOSG01S, GOTIM05S, GODIR05S, GOTIM04S, GODIR04S, GOSPW04S, JYY_- GOCE02S, EIGEN-6C2 and EGM2008 are also validated by using GPS-leveling data in China and USA. According to the truncation at degree 200, the statistic results show that all GGMs have very similar differences at GPS-leveling points in USA, and all GOCE related gravity models have better performance than EGM2008 in China. This suggests that all these models provide much more information on the gravity field than EGM2008 in areas with low terrestrial gravity coverage. And STDs of height anomaly differences in China for the selected truncation degrees show that GOCE has improved the accuracy of the global models beyond degree 90 and the accuracies of the models improve from 24 cm to 16 cm. STDs of geoid height differences in USA show that GOSG01S model has best consistency comparing with GPSleveling data for the frequency band of the degree between 20 and 160.
基金supported by the National Natural ScienceFoundation of China (Nos. 91014002,40821061)the SpecialFund for Basic Scientific Research of Central Colleges,China University of Geosciences (Wuhan) (No. CUGL100205)+1 种基金the Ph.D. Program Foundation of Ministry of Education of Chinafor Distinguished Young Scholars (No. 200804911523)the Ministry of Education of China (No. B07039)
文摘A detailed knowledge of the thickness of the lithosphere in the North China craton（NCC） is important for understanding the significant tectonic reactivation of the craton in Mesozoic and Ce-nozoic.We achieve this goal by applying the newly proposed continuous wavelet transform theory to the Gravity Field Model（EGM 2008） data in the region.Distinct structural variations are identified in the scalogram image of profile Alxa-Datong（大同）-Qingdao（青岛）-Yellow Sea（profile ABC）,trans-versing the main units of NCC,which we interpret as mainly representing the Moho and lithosphere-asthenosphere boundary（LAB） undulations.The imaged LAB is as shallow as 60-70 km in the south-east basin and coastal areas and deepens to no more than 140 km in the northwest mountain ranges and continental interior.A rapid change of about 30 km in the LAB depth was detected at around the boundary between the Bohai（渤海） Bay basin（BBB） and the Taihang（太行） Mountains（TM）,roughly coincident with the distinct gravity decrease of more than 100 mGal that marks the North-South Grav-ity Lineament（NSGL） in the region.At last we present the gravity modeling work based on the spectral analysis results,incorporating with the observations on high-resolution seismic images and surface to-pography.The observed structural differences between the eastern and western NCC are likely associ-ated with different lithospheric tectonics across the NSGL.Combined with seismic tomography results and geochemical and petrological data,this sug-gests that complex modification of the litho-sphere probably accompanied significant litho-spheric thinning during the tectonic reactivation of the old craton.
文摘Estimation of the zero-height geopotential value W_0^（LVD） for the CVD（China Vertical Datum） plays a fundamental role in the connection of traditional height reference systems into a global height system.Estimation the W_0^（LVD） of China is based on the computation of the mean geopotential offset between the value W_0= 62636856.0 m^2 s^（-2）, selected as reference in this study, and the unknown geopotential value W_0^（LVD）. This estimation is based on the combination of ellipsoidal heights, levelled heights（referring to the CVD）, and some physical parameters, such as geopotential values, gravity values, and geoid undulations.The geoid undulations derived from the GGM（Global Geopotential Models）. This combination is performed through three approaches： The first one is based on the theory of Molodensky, and the second one compares levelled heights and geopotential values derived from the GGMs, while the third one analyses the differences between GPS/Levelling and GGMs geoid undulations. The approaches are evaluated at 65 benchmarks（BMs） covered around Qingdao where the tide gauge is used to observe the local mean sea level of China. The results from three approaches are very similar. Furthermore, the W_0^（LVD）determined for the China local vertical datum was 62636852.9462 m^2 s^（-2）, indicates a bias of about3.0538 m^2/s^（-2） compared to the conventional value of 62636856.0 m^2 s^（-2）.
基金supported by the National Natural Science Foundation of China(Grant Nos.42474121 and 42192535)the Basic Frontier Science Research Program of the Chinese Academy of Sciences(Grant No.ZDBS-LY-DQC028).
文摘The Mohorovicic discontinuity(Moho)boundary separating the Earth’s crust and mantle reflects the evolutionary trajectory of the Earth’s crust,yielding crucial insights into crustal formation,tectonic evolution,and profound dynamic processes.However,the prevailing Moho models for China and its adjacent areas suffer from limited accuracy,owing to the irregular and sparse distribution of seismic data collection.In this study,we employ gravimetric data to derive Moho depth,and employ Bott’s regularization method,integrating gravity and seismic data to reconstruct the Moho structure with high precision in a three-dimensional framework across China and its adjacent areas.By optimizing gravity potential field separation and interface inversion techniques,we present a detailed and accurate zoning scheme for classifying China and its adjacent areas into 35 gradient belts,6 primary tectonic units,and 35 secondary tectonic units,based on the spatial distribution characteristics of the Moho discontinuity.Notably,our tectonic pattern division results surpass previous studies in terms of resolution,providing a wealth of tectonic information.Leveraging the Moho depth model of China and its adjacent areas,we discuss orogenic belts,sedimentary basins,fault systems,plate boundaries,and land-sea coupled tectonic patterns.We meticulously summarize the Moho depth distribution characteristics of each tectonic unit,while exploring the macrostructural framework and geological significance of the study area.Our findings highlight the close relationship between China and its adjacent areas Moho depth model and deep geodynamics,elucidating the tectonic evolution both between and within tectonic plates,as well as the tectonic effects induced by mantle dynamics.These insights have crucial implications for the study of deep geodynamics in China and its adjacent areas.
基金National 305 projection of Xinjiang Uygur Autonomous Region !(96-915-0703) Chinese Joint Seismological Science Foundation, b
文摘The latest geopotential model, EGM96, was employed to compute the free-air gravity anomaly, geoidal separation, the average density anomalies of the crust and the uppermost mantle, and the distribution pattern of the viscous stress exerted by mantle convection over Xinjiang and its neighboring areas. Based on these results and other data, we try to interpret the geodynamical features of the Tianshan orogen. Our research suggests that the Tianshan orogen is in a tectonic setting of compressive settling, driven by mantle convection. Under the effect of the compressive stress field, asymmetric in north-south direction, the Tianshan orogen upheaved quickly. The center of compressive stress field is in the south of the Tianshan, and the characteristic of stress field is favorable for the view point that the Tarim plat subducts beneath the Tianshan. The southern margin of the Juggar basin and the northern margin of the Tarim basin are two areas where the crust is of mass deficiency. We attribute the mass deficiency to the fact that the crust, in both the north and the south of the Tianshan is bent downwards under the compressive stress. Our research also indicates that the density distribution patterns in the deep of the eastern Tianshan are different from those in the middle and western Tianshan. It may be explained as the results from the east-west oriented distinction of the mantle convection.
