Influences of the Tibetan plateau on tidal gravity detected by using SGs at Lhasa, Lijiang and Wuhan Stations in China

Abstract

We accurately retrieved tidal gravimetric parameters using long-term continuous tidal gravity measurements recorded by superconducting gravimeters (SGs) at stations in Lhasa, Lijiang, and Wuhan, China. We used these results to investigate the influences of the special tectonic setting on regional tidal deformation. We accurately evaluated scale factors of SGs with high precision better than 0.06%. We carefully removed the effects of barometric pressure and oceanic loading from tidal gravity observations. We did not observe any obvious differences in amplitude factors for main tidal gravity waves for the stations in Lhasa and Lijiang. In the plateau area, we found the amplitude factor to be about 0.34% larger than that in the plain (Wuhan). Our study shows for the first time that the main reason for such tidal gravity anomalies can be explained by the influence of the special tectonic setting in the Tibetan Plateau.