EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Enormously large tippers observed in South-West of China. Can realistic 3-D modeling reproduce them?

Shan Xu1,2, Chaojian Chen3, Alexey Kuvshinov2, Mikhail Kruglyakov4, Rafael Rigaud2, and Xiangyun Hu1
Shan Xu et al.
  • 1School of Geophysics and Geomatics, China University of Geosciences, Wuhan, China (
  • 2Institute of Geophysics, ETH Zurich, Switzerland
  • 3Department of Earth and Environmental Sciences, Ludwig Maximilian University of Munich, Germany
  • 4Department of Physics, University of Otago, New Zealand
Vertical magnetic transfer functions (tippers) observed at a global/continental net of geomagnetic observatories can be used to image the electrical conductivity structure of the Earth down to a depth of around 200 km. We estimated tippers at 54 geomagnetic observatories across China, aiming eventually to invert them in terms of subsurface three-dimensional (3-D) conductivity distribution. Strikingly, we obtained enormously large tippers at three inland observatories in southwest China. Large tippers are often observed at coastal observatories due to the high lateral conductivity contrast between resistive continental bedrock and conductive seawater. However, tippers at those mentioned above observatories appeared to be a few times larger than coastal tippers. Moreover, as far as we know, such large tippers (reaching value 3) were never reported in any region of the world. We perform 3-D electromagnetic simulations mimicking the geological setting of the region and demonstrate that the enormously large tippers are feasible and can be attributed to a current channelling.


How to cite: Xu, S., Chen, C., Kuvshinov, A., Kruglyakov, M., Rigaud, R., and Hu, X.: Enormously large tippers observed in South-West of China. Can realistic 3-D modeling reproduce them?, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-4212,, 2023.