EGU2020-12579
https://doi.org/10.5194/egusphere-egu2020-12579
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Computing LPO for Geodynamic Models in ASPECT

Magali Billen and Menno Fraters
Magali Billen and Menno Fraters
  • University of California, Davis, Earth and Planetary Science, Davis, United States of America (mibillen@ucdavis.edu)

When modeling subduction processes, the results are usually constrained by looking at the geological surface expressions, geochemistry and geophysical observations such as tomography and seismic anisotropy. Of these observations, seismic anisotropy is the only type of observation that can potentially be directly linked to the spatial flow pattern in the mantle. Seismic anisotropy in the mantle is due to lattice-preferred orientation (LPO) of olivine minerals. In subduction environments, which can have complex and changing flow patterns, it is not expected that the LPO necessarily aligns with the flow pattern. This is partly due to the fact that it takes time to realign the LPO and partly because the olivine fast axis alignment depends on the water content and the magnitude of stress. To overcome this problem, the LPO must be computed for realistic and end member subduction zones in order to be able to relate seismic anisotropy to mantle flow and thereby slab dynamics.

There are many ways to compute LPO. For this study we have used DREX (Kaminski et al., 2004), because the underlying method is accurate and fast enough for use in geodynamic models. To achieve a good and native integration with ASPECT (Kronbichler et al., 2012; Heister et al., 2017; Bangerth et al,. 2019), we have rewritten DREX in CPP as a plugin for ASPECT. In this presentation we will show how it was implemented and what the limitations and possibilities are. Furthermore, we will show initial results from 3D subduction models to study the link between seismic anisotropy and mantle flow.

How to cite: Billen, M. and Fraters, M.: Computing LPO for Geodynamic Models in ASPECT, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12579, https://doi.org/10.5194/egusphere-egu2020-12579, 2020

Displays

Display file