Towards a Better Understanding of Non-Planar Geometrical Complexities of Faults: Including Geometrical Complexities Using the Flat Fault Approximation in Boundary Element Equation

Session: Crustal Stress and Strain and Implications for Fault Interaction and Slip [Poster]
Type: Poster
Date: 4/28/2020
Time: 08:00 AM
Room: Ballroom
Description: 

It is now known that faults are rough over a large order of scales. However, modeling these asperities on a wide number of scales is challenging when doing modeling. This is why some approximation may be done to simplify computational cost as well as the make easier the underlying mechanism. One common approximation when doing earthquake cycles is to assume flat fault. This leads to a much more complicated question: how can we incorporate non planar geometrical complexities, that are by definition non planar, and at the same time only modeling flat fault?

In this presentation, we show that assuming small elevation and small slope of fault surface (the fault is planar), it is actually possible to rigorously account for some geometrical complexities in boundary element method. We show that these geometrical complexities, at first order, acts only on the normal traction along the fault, while the shear traction depends mainly, again at first order, on the gradient of slip along the fault. We try to assess the reliability of this approximation when modeling earthquake cycle simulations. This opens new ways to understand better the effect of non-planarity on the faults.

Presenting Author: Pierre Romanet

Authors