ASPECT: Application to Problems in Long-Term Tectonics

While ASPECT was specifically designed to solve large-scale convection problems in the Earth’s mantle, the flexibility of its design permits examining solid Earth processes across a wide range of spatial and temporal scales.  Given this flexibility, a number of groups have begun applying ASPECT to long-term tectonic processes, such as subduction and continental extension, which require modeling both viscous and brittle behavior.  This form of constitutive relationship often leads to the development of shear bands (proxies for brittle faults), with the image below showing shear bands concentrating within a continental rift zone.  

Over the next year, CIG will look to expand ASPECT’s capabilities to model this type of long-term tectonic problem. Currently, planned developments include adding new constitutive relationships (viscoelasticity, gradient plasticity, velocity-dependent friction), coupling to surface processes models, optimization for faster run times and testing high resolution 3-D simulations.  If you would like to see additional features added to ASPECT, we welcome and encourage community feedback through the ASPECT developer email list (aspect-devel@geodynamics.org).

John Naliboff

 

 

Thermo-mechanical simulation showing deformation patterns (strain rate in s-1) arising from 10 Myr of continental extension (5 cm/yr).  Following previous studies, the constitutive relationship combines non-linear viscous flow and brittle behavior. The model domain spans 500 km (width) x 100 km (depth) and extension is driven by a combination of prescribed outflow along the model sides and balancing inflow at the base. The upper boundary is a free surface, which has been deformed by ductile shear zones to form a relatively symmetric rift valley.