Inversion of gravity and topography data for the crust thickness of China and its adjacent region

Abstract

The data of Bouguer gravity and topography are inverted to obtain the crust thickness of China. In order to reduce the effect of regional non-isostasy we corrected the reference Moho depth in the inversion with regional topography relief, and performed multiple iterations to make the result more reliable. The obtained crust thickness of China is plotted on a map in cells of 1°×1°. Then we analyzed the correlation between the Bouguer gravity anomaly and fluctuation of the Moho depth. A good linear correlation is found, with a correlation coefficient of −0.993. Different correlation coefficients, 0.96 and 0.91, are found for the data in land and ocean region, respectively. The correlation result also shows that the boundary between land and ocean is generally along the bathymetric line of −800 m. In order to examine the influence of the Earth′s curvature on the calculated result, we tried two inversion models: the inversion for the whole region and the inversion for 4 sub-regions. The difference in the crust thickness deduced from the two models is less than 5 km. Possible explanation for the difference is discussed. After comparing our result with that of other studies, we suggest that with our method the Bouguer gravity and the topography data can be independently inverted to obtain the crust thickness of China and its adjacency.

Analysis of the Thermal Structure of Lithospheric Mantle and Lithospheric Isostasy in China Continent

“…In order to eliminate regional perturbation, we tried a model with averaged values at 31 × 31 gridding points, corresponding to 1 • × 1 • spacing. The latitude and longitude of gridding points are consistent with those of the central points of each gridding space [7] . Parameters of lithospheric structure and physical quantities were taken from the tomography model of the Earth's interior [4] .…”

Source Mechanism of the 2006 MW5.1 Wen'an Earthquake Determined from a Joint Inversion of Local and Teleseismic Broadband Waveform Data

“…In this paper, when we do the local waveform inversion, we introduced and improved the velocity model of Beijing area from the reflection wave experiment [54] . Because of the tectonic complexity of Wen'an area [53,54] , we use different velocity models to calculate the Green's function for different stations. For the stations located to the east, north, and south of the epicenter, we use the model of Table 2.…”

Inverting Rayleigh surface wave velocities for eastern Tibet and western Yangtze craton crustal thickness based on deep learning neural networks

“…We use the Mineos package (Masters et al, 2014) to compute phase and group velocity for fundamental mode Rayleigh waves for all 100,000 synthetic 1-D earth models. 35 As for observation data used in stage of inversion below, it is worth noting that in principle, group and phase velocities carry the same information, although group velocities are more sensitive to the shallow structure. Since a larger part of the signal is affected by the crustal structure, combination two types of data will constrain crustal thickness better in the presence of noise.…”

“…Discontinuity between crust and mantle called moho discontinuity is an important one for geodynamics such as crustal evolution, tectonic activities and so on, in addition to the correcting gravity for the crustal effects, seismic 30 tomography and geothermal modeling. The depth of moho or called crust thickness varies greatly over small length scales and has significant effects on fundamental mode surface waves(Ueli Meier et al,2007).There are several methods to get moho depth, such as deep seismic sounding profile for china continent (Zeng et al,1995), inverting satellite gravity data to get whole global crust and lithophere thickness (Fang et al,1999), inverting Bouguer gravity and topography data to get moho depth for china 35 and its adjants (Huang et al,2008;Guo et al, 2012),inverting receiver function to get moho depth and Possion's ratio for china continent (Chen et al,2010;Zhu,2012 (Laske et al,2013;Stolk, et al, 2013) are based on refraction and reflection seismology as well as receiver function studies. As a consequence, resolution and consistence among different crust models are high in regions with good data coverage and uncomplicated structure but in 40 regions with poor or no data coverage or complicated structure crustal thickness estimates are largely extrapolated.…”