Introduction to Numerical Geodynamic Modelling

Gerya, Taras

doi:10.1017/cbo9780511809101

Cited by 285 publications

(410 citation statements)

References 342 publications

Supporting

Mentioning

393

Contrasting

Unclassified

Order By: Relevance

“…The models are solved using I3ELVIS code; it is based on the numerical solution of mass, momentum and energy conservation equations using finite difference method and marker-in cell techniques combined with a multigrid solver 23,24 . The staggered grid for which equations are solved includes 501 Â 165 Â 101 nodes with 100 million randomly distributed markers.…”

Section: Methodsmentioning

confidence: 99%

Oblique subduction modelling indicates along-trench tectonic transport of sediments

et al. 2013

Self Cite

View full text Add to dashboard Cite

Convergent plate margins are currently distinguished as 'accretional' or 'erosional', depending on the tendency to accumulate sediments, or not, at the trench. Accretion and erosion can coexist along the same margin and we have noticed that this mostly occurs where subduction is oblique. Here we show that at oblique subduction zones, sediments that enter the trench are first buried, and later migrate laterally parallel to the trench and at various depths. Lateral migration of sediments continues until they reach a physical barrier where they begin to accumulate. The accretionary wedge size decreases along the trench moving away from the barrier. We therefore suggest that the gradual variation of the accretionary wedge size and sediment amount at the trench along one single subduction zone, as observed in many active plate margins worldwide, can be explained by the lateral tectonic migration of sediments driven by obliquity of subduction as well.

show abstract

Section: Methodsmentioning

confidence: 99%

Oblique subduction modelling indicates along-trench tectonic transport of sediments

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…Our simulations were carried out using SiStER (Simple Stokes solver with Exotic Rheologies), a 2-D finite-difference/particle-incell code (Harlow & Welch 1965;Gerya & Yuen 2003 written in MATLAB R , and based on the methodology of Gerya (2010a). This code relies heavily on MATLAB (built-in) functions and capabilities for vector operations, and achieves computation speeds on par with standard serial compiled language codes.…”

Section: Numerical Methodologymentioning

confidence: 99%

“…Repeated indices imply summation and the first term in eq. (3) is the material time-derivative of T. These equations are discretized on an Eulerian (non-deforming) grid using a conservative finite difference scheme on a fully staggered grid (Gerya 2010a;Duretz et al 2011). The matrix equation for the discretization is defined in terms of the two velocity components and pressure, and then solved using the direct 'backslash' solver in MATLAB.…”

Section: Numerical Methodologymentioning

confidence: 99%

“…Deviatoric stress is carried on particles (Gerya 2010a;Keller et al 2013). Every time a velocity solution is obtained, the current strain rate field is used to update the deviatoric stress σ ij (t− t) by adding the stress increment σ ij , (after eq.…”

Section: Downloaded Frommentioning

confidence: 99%

“…50 per cent of the Courant condition). Properties are passed between nodes and particles through bilinear interpolation (Gerya 2010a). In particular, the advection term in eq.…”

mentioning

confidence: 99%

See 2 more Smart Citations

The role of elasticity in simulating long-term tectonic extension

et al. 2016

View full text Add to dashboard Cite

S U M M A R YWhile elasticity is a defining characteristic of the Earth's lithosphere, it is often ignored in numerical models of long-term tectonic processes in favour of a simpler viscoplastic description. Here we assess the consequences of this assumption on a well-studied geodynamic problem: the growth of normal faults at an extensional plate boundary. We conduct 2-D numerical simulations of extension in elastoplastic and viscoplastic layers using a finite difference, particle-in-cell numerical approach. Our models simulate a range of faulted layer thicknesses and extension rates, allowing us to quantify the role of elasticity on three key observables: fault-induced topography, fault rotation, and fault life span. In agreement with earlier studies, simulations carried out in elastoplastic layers produce rate-independent lithospheric flexure accompanied by rapid fault rotation and an inverse relationship between fault life span and faulted layer thickness. By contrast, models carried out with a viscoplastic lithosphere produce results that may qualitatively resemble the elastoplastic case, but depend strongly on the product of extension rate and layer viscosity U × η L . When this product is high, fault growth initially generates little deformation of the footwall and hanging wall blocks, resulting in unrealistic, rigid block-offset in topography across the fault. This configuration progressively transitions into a regime where topographic decay associated with flexure is fully accommodated within the numerical domain. In addition, high U × η L favours the sequential growth of multiple short-offset faults as opposed to a large-offset detachment. We interpret these results by comparing them to an analytical model for the fault-induced flexure of a thin viscous plate. The key to understanding the viscoplastic model results lies in the rate-dependence of the flexural wavelength of a viscous plate, and the strain rate dependence of the force increase associated with footwall and hanging wall bending. This behaviour produces unrealistic deformation patterns that can hinder the geological relevance of long-term rifting models that assume a viscoplastic rheology.

show abstract

The seismic cycle at subduction thrusts: Insights from seismo‐thermo‐mechanical models

et al. 2013

View full text Add to dashboard Cite

[1] The underestimation of the size of recent megathrust earthquakes illustrates our limited understanding of their spatiotemporal occurrence and governing physics. To unravel their relation to associated subduction dynamics and long-term deformation, we developed a 2-D continuum viscoelastoplastic model that uses an Eulerian-Lagrangian finite difference framework with similar on-and off-fault physics. We extend the validation of this numerical tool to a realistic subduction zone setting that resembles Southern Chile. The resulting quasi-periodic pattern of quasi-characteristic M8-M9 megathrust events compares quantitatively with observed recurrence and earthquake source parameters, albeit at very slow coseismic speeds. Without any data fitting, surface displacements agree with GPS data recorded before and during the 2010 M8.8 Maule earthquake, including the presence of a second-order flexural bulge. These surface displacements show cycle-to-cycle variations of slip deficits, which overall accommodate 5% of permanent internal shortening. We find that thermally (and stress) driven creep governs a spontaneous conditionally stable downdip transition zone between temperatures of 350 ı C and 450 ı C. Ruptures initiate above it (and below the forearc Moho), propagate within it, interspersed by small intermittent events, and arrest below it as ductile shearing relaxes stresses. Ruptures typically propagate upward along lithological boundaries and widen as pressures drop. The main thrust is constrained to be weak due to fluid-induced weakening required to sustain regular subduction and to generate events with natural characteristics (fluid pressures of 75-99% of solid pressures). The agreement with a range of seismological, geodetic, and geological observations demonstrates the validity and strength of this physically consistent seismo-thermo-mechanical approach.

show abstract

Introduction to Numerical Geodynamic Modelling

Cited by 285 publications

References 342 publications

Oblique subduction modelling indicates along-trench tectonic transport of sediments

Oblique subduction modelling indicates along-trench tectonic transport of sediments

The role of elasticity in simulating long-term tectonic extension

The seismic cycle at subduction thrusts: Insights from seismo‐thermo‐mechanical models

Contact Info

Product

Resources

About