1. Particle Methods in Tectonic Modelling October 27, 2003 Hans F. Schwaiger Sean Willett University of Washington Title

2. Dis-continuum Modelling in Geodynamics Analogue/Sandbox models Discrete Element Modelling (DEM) Smooth Particle Hydrodynamics (SPH) Outline

3. Fluid/Solid interaction with Brittle deformation Wu, et. al., 1998 Bertotti, et. al., 2000

4. Analogue/Sandbox Models Simulates Mohr-Coulomb behaviour Difficult to adjust model parameters Bonini and Sani., 2002 Persson and Sokoutis., 2002

5. Discrete Element Modelling Simulates granular material Forces are transmitted through contacts with neighbouring particles Accommodates large strain on discrete structures

6. DEM applied to lithospheric processes Burbidge, 2000 Saltzer, et. al., 1992 Accretionary wedges Extensional faulting

7. Smooth Particle Hydrodynamics Grid-Free Lagrangian Method Solves Continuum Equations Can handle an arbitrary constitutive law (in principle) Bonnet, 1999

8. SPH Formulations of Field Equations

9. Model testing 1-D Thermal 1-D Mechanical Couette FlowPoisouille Flow Heat Flow

10. Model testing 2-D Mechanical Monaghan, 1994 Inviscid Dam Burst

11. Adding Viscosity Low Viscosity

12. Adding Viscosity Medium Viscosity

13. Adding Viscosity High Viscosity

14. Folding of viscous layers

15. Accretionary Wedges Low Viscosity Medium Viscosity

16. Accretionary Wedges High Viscosity

17. Future work Add energy equation (2/3-D Heat flow, heat sources) Add non-linear stress in momentum equation Add erosion Parallelize code (necessary for 3-D)