A Reinvestigation of Crustal Thickness in the Tibetan Plateau Using Absolute Gravity, GPS and GRACE Data

  • Author(s): Wenke Sun, Qi Wang, Hui Li, Yong Wang, and Shuhei Okubo
  • DOI: 10.3319/TAO.2010.06.07.01(TibXS)
  • Keywords: Gravity change, GPS measurement, Tibetan Plateau, Mass loss, Crustal thickness
  • Citation: Sun, W., Q. Wang, H. Li, Y. Wang, and S. Okubo, 2011: A reinvestigation of crustal thickness in the Tibetan Plateau using absolute gravity, GPS and GRACE data. Terr. Atmos. Ocean. Sci., 22, 109-119, doi: 10.3319/TAO.2010.06.07.01(TibXS)
Abstract

The geodetic evidence of the uplift and crustal thickness of the Tibetan Plateau has been presented for the first time (Sun et al. 2009) using gravity and GPS observations. In this paper, we reinvestigate this tectonic deformation in more detail using GRACE data and taking the GIA effect into account. We first summarize the previous gravity and GPS observations and a local gravity network in the Dali County. The comparison between the surface absolute gravity and space GRACE gravity measurements shows that they are harmonic, agree well. Finally, we assume that the residual gravity change reflects material transport accompanying vertical movements on the crustal bottom; the crustal thickening rate is inferred as 1.9 ± 1.4 cm yr-1. As the crust thickens, the mass of a column of rock beneath the station decreases because mantle is displaced by crust, causing a reduction in gravity.

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