An efficient partial-differential-equation-based method to compute pressure boundary conditions in regional geodynamic models

Autor: A. Jourdon, D. A. May
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Solid Earth, Vol 13, Pp 1107-1125 (2022)
Druh dokumentu: article
ISSN: 1869-9510
1869-9529
DOI: 10.5194/se-13-1107-2022
Popis: Modelling the pressure in the Earth's interior is a common problem in Earth sciences. In this study we propose a method based on the conservation of the momentum of a fluid by using a hydrostatic scenario or a uniformly moving fluid to approximate the pressure. This results in a partial differential equation (PDE) that can be solved using classical numerical methods. In hydrostatic cases, the computed pressure is the lithostatic pressure. In non-hydrostatic cases, we show that this PDE-based approach better approximates the total pressure than the classical 1D depth-integrated approach. To illustrate the performance of this PDE-based formulation we present several hydrostatic and non-hydrostatic 2D models in which we compute the lithostatic pressure or an approximation of the total pressure, respectively. Moreover, we also present a 3D rift model that uses that approximated pressure as a time-dependent boundary condition to simulate far-field normal stresses. This model shows a high degree of non-cylindrical deformation, resulting from the stress boundary condition, that is accommodated by strike-slip shear zones. We compare the result of this numerical model with a traditional rift model employing free-slip boundary conditions to demonstrate the first-order implications of considering “open” boundary conditions in 3D thermo-mechanical rift models.
Databáze: Directory of Open Access Journals
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