[G04-P] Poster

[G04-P-03] The influence of mantle anelasticity on load response functions

Volker Klemann, Robert Dill, ^○Maik Thomas (GFZ German Research Centre for Geosciences, Potsdam, Germany)

Predefined response functions are applied to parametrize the effect of load deformation due to seasonal mass redistribution in geodetic correction models, e.g., for GRACE or GPS networks. The correction models are usually based on accepted 1D earth structures like PREM, iaspr or ak135. All these structures represent global means, where, at most, oceanic and continental lithospheric structures are distinguished. One aspect present in the earth's mantle but usually not considered is the impact of anelasticity. As a temperature and material dependent behaviour, anelastic attenuation shows significant lateral variability, especially in the mantle asthenosphere, e.g., at active plate boundaries (Andes, Himalaya) versus passive cratonic regions (North American shield).
In this study, we consider attenuation according to seismological inferences. In order to predict the relaxation of the shear modulus on tidal and seasonal time scales, we extrapolate the constant Q model, which is defined for the seismic band, to these longer time periods.
Based on this approach, we assess the impact on the load Love number spectrum and on the resulting Green's functions. Furthermore, this approach is applied in order to analyse the effect on ocean and atmospheric loading products.