Quantifying the energy dissipation of overriding plate deformation in three‐dimensional subduction models

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 (F OPD ) that drives overriding plate deformation and the associated energy dissipation rate (Φ OPD ), and we compare them with the negative buoyancy (F BU ) of the subducted slab and its total potential energy release rate (Φ BU ), respectively. We varied the viscosity ratio between the plates and the sublithospheric upper mantle with η SP /η UM = 157-560 and the thickness of the overriding plate with T OP = 0.5-2.5 cm (scaling to 25-125 km in nature). The results show that F OPD /F BU has average values of 0.5-2.0%, with a maximum of 5.3%, and Φ OPD /Φ BU 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).

A review of analogue modelling of geodynamic processes: Approaches, scaling, materials and quantification, with an application to subduction experiments

“…Goren et al, 2008), buoyancy-driven subduction models (e.g. Jacoby, 1973;Kincaid and Olson, 1987;Funiciello et al, 2003Funiciello et al, , 2006Funiciello et al, , 2008Schellart, 2004aSchellart, , 2008Schellart, , 2010aBellahsen et al, 2005;Guillaume et al, 2009Guillaume et al, , 2010Duarte et al, 2013;Strak and Schellart, 2014;Chen et al, 2015aChen et al, ,b, 2016, buoyancy-driven continental subduction experiments (e.g. Edwards et al, 2015), and experiments investigating Rayleigh-Taylor instabilities (e.g.…”

“…Faugere and Brun, 1984;Cobbold, 1988, 1991;Faccenna et al, 1996Faccenna et al, , 1999Schellart et al, 2002a,b;Regard et al, 2003Regard et al, , 2005Willingshofer and Sokoutis, 2009;Luth et al, 2013a), or the entire lithosphere (e.g. Funiciello et al, 2003Funiciello et al, , 2006Schellart, 2004aSchellart, , 2008Bellahsen et al, 2005;Guillaume et al, 2009Guillaume et al, , 2010Irvine and Schellart, 2012;Duarte et al, 2013;Martinod et al, 2013;Strak and Schellart, 2014;Chen et al, 2015aChen et al, , 2015b. A significant number of analogue models use visco-plastic and non-linear viscous materials, either exclusively or in combination with linear viscous materials.…”

“…In subduction experiments, quantifying motion and velocity of the trench, trailing edge of the subducting plate and, when present, trailing edge of the overriding plate is common (e.g. Jacoby, 1973;Kincaid and Olson, 1987;Guillou-Frottier et al, 1995;Funiciello et al, 2003;Schellart, 2004a;Duarte et al, 2013;Chen et al, 2015a). When measuring displacements and velocities, data accuracy and precision depend on pixel resolution.…”

“…Algorithms have been used to compute displacement and strain fields from square grids and grids made of points (e.g. Bellahsen et al, 2003;Fournier et al, 2004;Duarte et al, 2013;Chen et al, 2015aChen et al, , 2015b. Such algorithms include the software Dynel (Maerten and Maerten, 2006) used in subduction modelling by Bellahsen et al (2003), and SSPX (Cardozo and Allmendinger, 2009) used in subduction experiments by Duarte et al (2013) and Chen et al (2015aChen et al ( , 2015b.…”

Overriding plate deformation and variability of fore‐arc deformation during subduction: Insight from geodynamic models and application to the Calabria subduction zone

“…Previous modeling works have also investigated the influence of laterally free versus laterally fixed plates on the dynamics of subduction, but those models either excluded an overriding plate [e.g., Kincaid and Olson , ; Funiciello et al ., ; Schellart , ] or were set up in two‐dimensional space [e.g., Capitanio et al ., ; Quinquis et al ., ; Nakakuki and Mura , ; Holt et al ., ], such that these models could not take into account the influence of lateral slab edges and the trench‐parallel variability in subduction zone size on the dynamics of subduction [ Schellart et al ., ]. Only recently fully dynamic time‐evolving models of subduction in three‐dimensional space were developed with both a subducting and an overriding plates using numerical modeling techniques [e.g., van Hunen and Allen , ; Butterworth et al ., ; Schellart and Moresi , ; Malatesta et al ., ; Rodríguez‐González et al ., ; Sternai et al ., ; Capitanio , ] or laboratory modeling techniques [e.g., Meyer and Schellart , ; Duarte et al ., ; Chen et al ., ]. In the laboratory models mentioned above, a weak interplate rheology was applied to allow for low coupling and efficient interface lubrication.…”