Introduction and benchmarking The convection of the Earth’s mantle is usually modelled as an incompressible process, referred to as the Boussinesq approximation. However, in the Earth’s mantle, the pressure increase associated with depth also increases the density due to self-compression (King et al. 2010). In some applications, this compressibility may be non-negligible and modelling it may be desirable.
Issues with intra-element discontinuities in PIC-FEM The classical finite element method (FEM) has been widely used to simulate diverse problems in engineering. Unlike most engineering problems, geological simulations are dominated by emergence of geometrical structures due to the non-linear processes involved.
Meghan S. Miller, Australian National University and Louis Moresi, Australian National University Our responses to the COVID-19 pandemic have dramatically changed human activity all over the world. People are working from home, schools are closed in many places, travel is restricted, and in some cases only essential shops and businesses are open. Scientists see signs of these changes wherever they look.
The Underworld team would like to congratulate Bénédicte Cenki-Tok and co-authors at the University of Sydney and the University of Montpellier on their recent publication, B. Cenki-Tok, P.F. Rey, D. Arcay;
Viscoelastic materials exhibit the properies of both solids and liquids, with deformation rates dependent on both the viscous stress and elastic stress rate.
Making your research reproducible means that you provide the entire workflow from data, through software and post-processing freely available. Not only can somebody repeat your experiments and verify them, they can build upon them. In lab-based disciplines, there are many further challenges, but in research that is predominantly based on data processing, this ought to be an achievable goal.
(they don't make them like they used to ... ) Cratons are anomalously-strong regions of the continents that have largely resisted tectonic forces for billions of years. How such strong zones could be forged in a hot, low-viscosity, low stress, early-Earth has been a long-standing puzzle for geologists.
Modelling the relative time-scales of the Rayleigh-Taylor Instability and delamination, using Underworld With Adam Beall, Cardiff University. Why model sub-continental gravitational instabilities? Within the plate tectonics framework, continents are generally considered to have a much lower density than the asthenosphere below and therefore avoid the kind of recycling that the oceanic crust and lithosphere undergoes.
In honour of Hans Mühlhaus' 70th birthday this month, here are some shear band simulations made with Underworld. We are investigating the role of dilatancy in the geometry of the shear bands for a box of material when a small trapdoor is opened. The extent to which large-scale deformation is needed to release material through the trapdoor depends on how much the material dilates when shear bands form.
In a recent paper [1], we used Underworld models to examine subduction congestion associated with the ingestion of a continental ribbon. The SE Australian geological record turned out to be a wonderful place to study this process. Here is a short summary of the work for a relatively non-technical audience that we put together and some additional figures which I prepared.
