Change search
ReferencesLink to record
Permanent link

Direct link
Lithospheric-Scale Stresses and Shear Localization Induced by Density-Driven Instabilities
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
2010 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

The initiation of subduction requires the formation of lithospheric plates which mostly deform at their edges. Shear heating is a possible candidate for producing such localized deformation. In this thesis we employ a 2D model of the mantle with a visco-elasto-plastic rheology and enabled shear heating. We are able to create a shear heating instability both in a constant strain rate and a constant stress boundary condition setup. For the rst case, localized deformation in our specic setup is found for strain rates of 10-15 1/s and mantle temperatures of 1300°C. For constant stress boundaries, the conditions for a setup to localize are more restrictive. Mantle motion is induced by large cold and hot temperature perturbations. Lithospheric stresses scale with the size of these perturbations; maximum stresses are on the order of the yield stress (1 GPa). Adding topography or large inhomogeneities does not result in lithospheric-scale fracture in our model. However, localized deformation does occur for a restricted parameter choice presented in this thesis. The perturbation size has little effect on the occurrence of localization, but large perturbations shorten its onset time.

Place, publisher, year, edition, pages
2010. , 75 p.
Examensarbete vid Institutionen för geovetenskaper, ISSN 1650-6553 ; 187
Keyword [en]
Lithosphere, localization, numerical modeling, shear heating, stress, subduction initiation
National Category
Natural Sciences
URN: urn:nbn:se:uu:diva-183725OAI: diva2:563931
Subject / course
Educational program
Master Programme in Physics
Life Earth Science
Available from: 2012-11-01 Created: 2012-10-31 Last updated: 2012-11-01Bibliographically approved

Open Access in DiVA

fulltext(7264 kB)398 downloads
File information
File name FULLTEXT02.pdfFile size 7264 kBChecksum SHA-512
Type fulltextMimetype application/pdf

By organisation
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 398 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 244 hits
ReferencesLink to record
Permanent link

Direct link