The Solid Earth is – literally or figuratively – the bedrock of surface processes. The Solid Earth is also a dynamic system that consists of an internally driven part and the externally forced response to surface changes.
The internal part is called mantle convection and plate tectonics. It is driven by transfer of heat from the deep Earth and affected by the 3D viscosity structure. At hotspot volcanoes, there is a direct connection between surface processes and convection, possibly reaching all the way to the Earth’s core. A poignant example of the Solid Earth’s responsiveness is post-glacial uplift: Ice masses deform the Earth’s surface and once the ice is molten, elastic and viscous forces restore the former shape of the surface, explaining the uplift rates of up to a cm per year observed in Scandinavia today. Regarding horizontal motion, it is well known that plate tectonics is closely related to earthquake occurrence and distribution.
The role of a Digital Twin of the Solid Earth (DTSE) is thus two-fold:
- Account for changes in the Solid Earth that might obfuscate observations of other surface processes.
- Consider the response of the Solid Earth when predicting scenarios of Earth’s future evolution.
Within the 4D Dynamic Earth project a characterisation of processes, methodologies, data, models and algorithms is made for the future DTSE.