The effect of pressure-temperature dependent material properties on thermal evolution of the slab

The rheological and compositional evolution of a subducting plate critically depends on its thermal structure. The temperature evolution of the subducting plate depends on its history prior to subduction, on its interaction with the overriding plate, and on how it interacts with the ambient mantle. Many processes that are associated with subduction such as deep seismicity and fluid release, which are responsible for arc-volcanism, can be understood through the temperature evolution of the slab. Studying the temperature evolution of the subducting slab, however, is not straightforward because of the lack of direct observations and a complete subduction record. Thus, to assist the interpretation of the available data it is necessary to use forward geodynamic modelling (FWG).

FWG can either study a full dynamic system or study the evolution of the slab using a kinematic model, in which the slab geometry and velocity are fully prescribed as boundary conditions. Kinematic models are more suitable to study specific subduction zones, as the dynamic models would require high computational cost to fit the available data. However, kinematic models suffer from several assumptions that oversimplify the complexity of the subduction process. For example, kinematic models are frequently performed with constant convergence velocity, age of subducting plate, and thermal properties. 

In this contribution, we aim to test whether the pressure- and temperature-dependent thermal properties improve our ability to interpret the natural data, and if the improvements are worth the additional complexity.