Deformations of a viscoelastic lithosphere
Volker Klemann (WWU Münster), Detlef Wolf (GFZ Potsdam)
The present study is restricted to plane, compressible, viscoelastic
earth models and differentiates between the contributions of the
individual terms in the incremental equation of motion to the solution
for load-induced deformation. Neglecting the gravitational-mechanical
coupling and inertial forces in the equation of motion, this equation
expresses the balance between three force terms:
1. viscoelastic stress, 2. advected initial stress and 3. internal
buoyancy. We investigate the following combinations: term 1 + term 2
(initial stress) and term 1 + term 2 + term 3 (initial stress + internal
buoyancy). For comparison, we also consider the incompressible case.
We investigate the general properties of the solutions for a uniform
viscoelastic half-space and discuss the adequacy of the normal-mode
expansion for the different cases. We also consider an elastic layer
overlying a fluid half-space and study the influence of the individual
terms on the vertical and horizontal displacements. Finally, we consider
an elastic half-space and investigate their influence on the incremental
gravity.