Models of interseismic deformation with an analytic framework for the inclusion of general linear viscoelastic rheologies

I investigate postseismic and interseismic deformation using two-dimensional models of a vertical strike-slip fault in an elastic layer over a viscoelastic region. Central to this, I derive an analytic framework to include general linear viscoelastic theologies into models of interseismic deformation. Models with multi-viscous viscoelastic rheologies predict multiple phases of postseismic and interseismic deformation. For instance, with bi-viscous Burgers rheologies there is transient deformation early in the seismic cycle, while the deformation is steady later in the cycle. Only layered models with multi-viscous rheologies predict multiphase postseismic deformation. Fault models containing a steady component of relaxation, evolve to mature states after a sufficient number of fault ruptures. The mature surface deformation is unrelated to the steady deformation at depth and depends only on the rupture history and locking depth of the fault and the theologies of the model. With periodic ruptures, the mature deformation is cycle invariant. If the recurrence time or magnitude of the ruptures then change, the interseismic velocities vary significantly from cycle to cycle as they evolve toward new cycle invariant velocities.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Earth, Atmospheric, and Planetary Sciences.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Hetland, Eric Andreas

Advisor dc:contributor.advisor

• Bradford H. Hager.

• Earth, Atmospheric, and Planetary Sciences.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/34565

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/34565