Abstract

Modelling the lithostatic pressure in the Earth's interior is a common problem in Earth sciences. In this study we propose to compute the lithostatic pressure from the conservation of momentum reduced to the hydrostatic particular case. It results a partial differential equation that can be solved using the classical numerical methods. To show the usefulness of solving a PDE to compute the lithostatic pressure we propose two 2D models, one with a deformed mesh and one with a radial gravity acceleration vector and a concentric density distribution. Moreover, we also present a 3D rift model using the lithostatic pressure as a boundary condition. This model shows a high non cylindricity resulting from the Neumann boundary condition that is accomodated by strike-slip shear zones. We compare the result of this numerical model with a simple free-slip boundary conditions model to demonstrate the first order implications of considering "open" boundary conditions in 3D thermo-mechanical models.

Highlights

  • In Earth sciences and geodynamic modelling, computing the lithostatic pressure can be essential

  • 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 propose an efficient, mesh and numerical method independent way to compute the lithostatic pressure for all scenarios 1-5 above by solving a partial differential equation (PDE) for a hydrostatic equilibrium fluid

Read more

Summary

Introduction

In Earth sciences and geodynamic modelling, computing the lithostatic pressure can be essential. I Di i where ρi is the density at the centroid of the segment Di. For the case of a uniform mesh with cell edges aligned with the gravity vector, all the cell edges / vertices are located along straight lines which are parallel to the direction of gravity. Eq (2) can be evaluated by traversing along a column associated with a set of cells (or vertices) In this special case, the sub-division of the integral is naturally defined by mesh cells. When performing simulations in parallel where the mesh is distributed 50 across multiple MPI ranks, even for the case of a uniform mesh aligned with the gravity vector the column-wise integration approach is somewhat complicated. 60 applied to Earth sciences and geodynamics to show the usefulness of this approach

PDE based lithostatic pressure formulation
Weak formulation
Numerical examples
Physical model
Initial conditions and rheology
Boundary conditions
Tectonics evolution
Implication on lithosphere deformation
Conclusions
265 Acknowledgements
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.