The evolution of ice loads during the last Ice Age causes an ongoing Earth response with deformations and stress fields. The viscosity of the mantle depends on stresses, therefore the model stresses should be combined with ambient stresses such as due to mantle convection. This combination has been successfully simulated in the FEM software ABAQUS.

At each timestep background stresses are added to existing component and the Mises stress is recalculated to be used in a custom creep law. This leads to a new viscosity leading to different stress components, which is solved an iterative procedure.

This work shows that the initial model provided can be adapted to simulate this iterative process with a loop inside each timestep of the computation. Results show that stresses increase with time while deformations and viscosity decrease, an opposite trend compared to a non-ambient stresses case.