Task 7: Global plate motion and its sensitivity to the 4D Earth model
Based on reported, current major plate motion and Euler pole locations (estimated with GNSS time series, e.g. Jagoda (2021), Vardić (2022)) we will evaluate the general accuracy of plate motion estimates. We will consider different approaches of estimating plate motion models, e.g. with or without consideration of GIA, and estimate a multi-model combined probability for Euler pole and rotation velocities.
Moreover, in this task, we will define scenarios for estimating how soon changes of plate rotation could be detected, based on currently deemed realistic dynamics of mantle convection and plate boundary physics.
Lastly, we would like to evaluate if large scale vertical motions correlate with predicted dynamic topography and/or with changes in the gravity field. To approach this question we will focus on global vertical motion measurements based on GNSS and first estimate the accuracy of estimated motion nearly linear in time.
Workpackages Task 7
We will put the accuracy in context with surface motions estimated in mantle convection models to assess the significance of mismatch. An outcome will be a global inventory of plate motion models from recent literature, from which we compile a multi-model combined probability of the plate motion parameters.
In this WP we will:
1) Test how changes in plate motion direction and speed affect single GNSS station and network solutions.
2) Compare Euler pole and rotation speed changes with the accuracy of current plate motion models as estimated in WP7000 and estimate the sensitivity threshold for such changes with GNSS systems as of today. This threshold estimation will be complemented by projections into the future assuming longer times series and more GNSS stations. A test case will be changes of the motion of the Anatolian plate.
We will extract large-scale vertical motion signals and propagate accuracy estimation to larger wavelength signals. These observations are then put into context with predicted dynamic topography and predicted changes in dynamic topography.