EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Benchmark of numerical GIA codes capable of laterally heterogeneous earth structures

Volker Klemann1, Jacky Austermann2, Meike Bagge1, Natasha Barlow3, Jeffrey Freymueller4, Pingping Huang1,5, Erik R. Ivins6, Andrew Lloyd7, Zdeněk Martinec8,9, Glenn Milne10, Alessio Rovere11,12, Holger Steffen13, Rebekka Steffen13, Wouter van der Wal14, Maryam Yousefi15,16, and Shijie Zhong17
Volker Klemann et al.
  • 1GFZ German Research Centre for Geosciences, Geodesy 1.3, Potsdam, Germany (,,
  • 2Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States (
  • 3Faculty of Environment, School of Earth and Environment, University of Leeds, Leeds, United Kingdom (
  • 4Department of Earth and Environmental Sciences, Michigan State University, East Lansing, MI, United States (
  • 5School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
  • 6Jet Propulsion Lab, California Institute of Technology, Pasadena, CA, United States (
  • 7Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States (
  • 8Dublin Institute for Advanced Studies,Dublin, Ireland (
  • 9Department of Geophysics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
  • 10Department of Earth and Environmental Sciences, University of Ottawa, Ottowa, ON, Canada (
  • 11Ca' Foscari University of Venice, Venice, Italy
  • 12MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany (
  • 13Geodetic Infrastructure, Lantmäteriet, Gävle, Sweden (,
  • 14Delft University of Technology, Faculty of Aerospace Engineering, Delft, The Netherlands (
  • 15Department of Earth and Planetary Sciences, McGill University, Montreal, Quebec, Canada (
  • 16Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA, United States
  • 17Department of Physics, University of Colorado at Boulder, Boulder, CO, United States (

During the last decade there has been an increasing demand to improve models of present-day loading processes and glacial-isostatic adjustment (GIA). This is especially important when modelling the GIA process in tectonically active regions like the Pacific Northwest, Patagonia or West Antarctica. All these regions are underlain by zones of low-viscosity mantle. Although one-dimensional earth models may be sufficient to model local-scale uplift within these regions, modeling of the wider-scale deformation patterns requires consideration of three-dimensional viscosity structure that is consistent with other geophysical and laboratory findings. It is this wider-scale modeling that is necessary for earth-system model applications as well as for the validation or reduction of velocity fields determined by geodetic observation networks based on GNSS, for improving satellite gravimetry, and for present-day sea-level change as paleo sea-level reconstructions.

There are a number of numerical GIA codes in the community, which can consider lateral variations in viscoelastic earth structure, but a proper benchmark focusing on lateral heterogeneity is missing to date. Accordingly, ambiguity remains when interpreting the modelling results. The numerical codes are based on rather different methods to solve the respective field equations applying, e.g., finite elements, finite volumes, finite differences or spectral elements. Aspects like gravity, compressibility and rheology are dealt with differently. In this regard, the set of experiments to be performed has to be agreed on carefully, and we have to accept that not all structural features can be considered in every code.

We present a tentative catalogue of synthetic experiments. These are designed to isolate different aspects of lateral heterogeneity of the Earth's interior and investigate their impact on vertical and horizontal surface displacements, geocenter and polar motion, gravity, sea-level change and stress. The study serves as a follow up of the successful benchmarks of Spada et al. (2011) and Martinec et al. (2018) on 1D earth models and the sea-level equation. The study was initiated by the PALSEA-SERCE Workshop in 2021 (Austermann and Simms, 2022) and benefits from discussions inside different SCAR-INSTANT subcommittees, the IAG Joint Study Group 3.1 “Geodetic, Seismic and Geodynamic Constraints on Glacial Isostatic Adjustment", the IAG Subcommission 3.4 “Cryospheric Deformation" and PALSEA.


Austermann, J., Simms, A., 2022 (in press). Unraveling the complex relationship between solid Earth deformation and ice sheet change. PAGES Mag., 30(1). doi:10.22498/pages.30.1.14

Martinec, Z., Klemann, V., van der Wal, W., Riva, R. E. M., Spada, G., Sun, Y., Melini, D., Kachuck, S. B., Barletta, V., Simon, K., A, G., James, T. S., 2018. A benchmark study of numerical implementations of the sea level equation in GIA modelling. Geophys. J. Int., 215:389-414. doi:10.1093/gji/ggy280

Spada, G., Barletta, V. R., Klemann, V., Riva, R. E. M., Martinec, Z., Gasperini, P., Lund, B., Wolf, D., Vermeersen, L. L. A., King, M. A. (2011). A benchmark study for glacial isostatic adjustment codes. Geophys. J. Int., 185:106-132. doi:10.1111/j.1365-246X.2011.04952.x

How to cite: Klemann, V., Austermann, J., Bagge, M., Barlow, N., Freymueller, J., Huang, P., Ivins, E. R., Lloyd, A., Martinec, Z., Milne, G., Rovere, A., Steffen, H., Steffen, R., van der Wal, W., Yousefi, M., and Zhong, S.: Benchmark of numerical GIA codes capable of laterally heterogeneous earth structures, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1447,, 2022.