Projects per year
Abstract
In a subduction system the force and the energy required to deform the overriding plate are generally thought to come from the negative buoyancy of the subducted slab and its potential energy, respectively. Such deformation might involve extension and back-arc basin formation or shortening and mountain building. How much of the slab's potential energy is consumed during overriding plate deformation remains unknown. In this work, we present dynamic three-dimensional laboratory experiments of progressive subduction with an overriding plate to quantify the force (FOPD) that drives overriding plate deformation and the associated energy dissipation rate (ΦOPD), and we compare them with the negative buoyancy (FBU) of the subducted slab and its total potential energy release rate (ΦBU), respectively. We varied the viscosity ratio between the plates and the sublithospheric upper mantle with ηSP/ηUM = 157-560 and the thickness of the overriding plate with TOP = 0.5-2.5 cm (scaling to 25-125 km in nature). The results show that FOPD/FBU has average values of 0.5-2.0%, with a maximum of 5.3%, and ΦOPD/ΦBU has average values of 0.05-0.30%, with a maximum of 0.41%. The results indicate that only a small portion of the negative buoyancy of the slab and its potential energy are used to deform the overriding plate. Our models also suggest that the force required to deform the overriding plate is of comparable magnitude as the ridge push force. Furthermore, we show that in subduction models with an overriding plate bending dissipation at the subduction zone hinge remains low (3-15% during steady state subduction).
Original language | English |
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Pages (from-to) | 519-536 |
Number of pages | 18 |
Journal | Journal of Geophysical Research: Solid Earth |
Volume | 120 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2015 |
Keywords
- Analog modeling
- Energy dissipation
- Negative buoyancy
- Overriding plate deformation
- Overriding plate deformation force
- Subduction
Projects
- 2 Finished
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The Cenozoic tectonic evolution of East and Southeast Asia: Interplay between the India-Eurasia collision and the Pacific and Sunda subduction zones
Schellart, W.
Australian Research Council (ARC), Monash University
1/01/12 → 15/09/16
Project: Research
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Three-dimensional subduction models of overriding plate deformation and mantle flow using laboratory and numerical methods
Schellart, W., Cruden, A. & Stegman, D.
Australian Research Council (ARC), Monash University
4/01/11 → 1/10/14
Project: Research