Models of interseismic deformation with an analytic framework for the inclusion of general linear viscoelastic rheologies
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2006.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2006
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| Online Access: | http://hdl.handle.net/1721.1/34565 |
| _version_ | 1826196332510969856 |
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| author | Hetland, Eric Andreas |
| author2 | Bradford H. Hager. |
| author_facet | Bradford H. Hager. Hetland, Eric Andreas |
| author_sort | Hetland, Eric Andreas |
| collection | MIT |
| description | Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2006. |
| first_indexed | 2024-09-23T10:25:14Z |
| format | Thesis |
| id | mit-1721.1/34565 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T10:25:14Z |
| publishDate | 2006 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/345652019-04-11T13:00:33Z Models of interseismic deformation with an analytic framework for the inclusion of general linear viscoelastic rheologies Hetland, Eric Andreas Bradford H. Hager. Massachusetts Institute of Technology. Dept. of Earth, Atmospheric, and Planetary Sciences. Massachusetts Institute of Technology. Dept. of Earth, Atmospheric, and Planetary Sciences. Earth, Atmospheric, and Planetary Sciences. Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2006. Includes bibliographical references. 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. (cont.) The time for a model to equilibrate to an invariant state is proportional to the time scale of the steady component of viscoelastic relaxation, and the effect of prior fault activity is only negligible in models with weak theologies. The interseismic deformation observed both before and after the 2004 Parkfield, CA, and 1999 Izmit, Turkey, earthquakes can be approximated by a model with multi-viscous viscoelastic rheologies. The deformation at Parkfield is approximated using a rheology with possibly two transient viscous phases (relaxation times about one and 3-12 months) and a steady viscous phase with a time scale much longer than 20 years. The deformation at Izmit is described by a model with a Burgers rheology with transient and steady relaxation times of three years and about 500 years or more. by Eric Andreas Hetland. Ph.D. 2006-11-07T13:00:08Z 2006-11-07T13:00:08Z 2006 2006 Thesis http://hdl.handle.net/1721.1/34565 71196339 eng 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. http://dspace.mit.edu/handle/1721.1/7582 255 p. 47586545 bytes 47585730 bytes application/pdf application/pdf application/pdf Massachusetts Institute of Technology |
| spellingShingle | Earth, Atmospheric, and Planetary Sciences. Hetland, Eric Andreas Models of interseismic deformation with an analytic framework for the inclusion of general linear viscoelastic rheologies |
| title | Models of interseismic deformation with an analytic framework for the inclusion of general linear viscoelastic rheologies |
| title_full | Models of interseismic deformation with an analytic framework for the inclusion of general linear viscoelastic rheologies |
| title_fullStr | Models of interseismic deformation with an analytic framework for the inclusion of general linear viscoelastic rheologies |
| title_full_unstemmed | Models of interseismic deformation with an analytic framework for the inclusion of general linear viscoelastic rheologies |
| title_short | Models of interseismic deformation with an analytic framework for the inclusion of general linear viscoelastic rheologies |
| title_sort | models of interseismic deformation with an analytic framework for the inclusion of general linear viscoelastic rheologies |
| topic | Earth, Atmospheric, and Planetary Sciences. |
| url | http://hdl.handle.net/1721.1/34565 |
| work_keys_str_mv | AT hetlandericandreas modelsofinterseismicdeformationwithananalyticframeworkfortheinclusionofgenerallinearviscoelasticrheologies |