Characterization of the tectonic structures on the Tibetan Plateau using gravity anomaly data and an improved edge detection method

Abstract Edge detection plays an important role in interpreting geophysical potential field data and revealing faults, contacts, and other linear tectonic structures. Various methods have been proposed to detect and enhance edges; however, they are often sensitive to noise, unable to adequately balance amplitude information across different depths, and may introduce false edges that require manual removal. To overcome these limitations, we present an improved method called the hyperbolic tangent function with Gaussian envelope constraints on the horizontal gravity gradient tilt angle (THTAHG) that is based on the tilt angle of the horizontal gravity gradient and the hyperbolic tangent (TANH) function under Gaussian envelope constraints. The applicability of the method is illustrated with three synthetic models and actual gravity data. Compared with existing edge detection techniques, our method provides clearer and more precise identification results, with enhanced stability and without introducing spurious boundaries. Finally, to address the problem of the plate boundary division and internal response of the Tibetan Plateau, this research studies the characteristics of the distribution of the tectonic structures of the Tibetan Plateau and its surroundings on the basis of the THTAHG method with Bouguer gravity anomaly data. A total of 20 fault zones are identified, which have been verified by previous studies. We verify the existence of the central uplift zone of the Qiangtang Basin. These experiments demonstrate that this work provides an effective method for studying tectonic boundaries and geodynamic evolution. Graphical Abstract