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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. Savage (2000). Bourne et al. [1998]
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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
Savage (2000) • 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] • “ 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 Velocity in the lower crust Driving solution:
Viscoelastic-Coupling model driven from below Stress at the bottom of the upper crust Driving solution:
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).