Viscoelastic-coupling model for the earthquake cycle driven from below J.C. Savage U.S. Geological Survey, Menlo Park, CA Ge 277, Thomas ADER, January 27, 2011

Representation of the Bourne’s Model. Bourne et al. [1998] “ The intersismic velocity profile across a transform fault at the surface would be a replica of a similar profile at the top of the upper mantle. ” Savage (2000) Savage [2000] “ For a linear system, (…) interseismic deformation along such a profile (…) is determined by the parameters H and t0 and does not depend at all upon the velocity profile at the top of the upper mantle. ” T, recurrence time of earthquakes Representation of the Bourne’s Model. relaxation time Savage (2000)

Viscoelastic-Coupling model driven by the Schizosphere stress guide Surface velocity time evolution

Viscoelastic-Coupling model driven by the Schizosphere stress guide Depth velocity time evolution

Viscoelastic-Coupling model driven by the Schizosphere stress guide Stress plastosphere -> schizosphere time evolution > 0

Viscoelastic-Coupling model driven by the Schizosphere stress guide Dependence with

Viscoelastic-Coupling model driven from below Same problem as before with boundary condition locked at depth + driving solution that provides driving force. Boundary condition locked at the top

Viscoelastic-Coupling model driven from below Surface velocity Same as before, but with boundary condition at y = H+D.

Viscoelastic-Coupling model driven from below Stress at the bottom of the upper crust

Viscoelastic-Coupling model driven from below Driving solution: Velocity in the lower crust

Viscoelastic-Coupling model driven from below Driving solution: Stress at the bottom of the upper crust

Conclusion Surface displacement doesn’t depend on the displacement of the upper mantle Surface displacement depends on the parameters H (thickness of the schizosphere) and t0 Model valid only where the Earth model is linear (superposition of solutions).