BurnMan: A Lower Mantle Mineral Physics Toolkit

We present BurnMan (www.burnman.org), a python based, open-source toolbox to determine seismic velocities for specified compositions in the lower mantle. BurnMan calculates the isotropic thermoelastic moduli by solving the Equations-of-State (EoS) for a mixture of minerals defined by the user. BurnMan includes various libraries of lower mantle minerals or users can easily define their own. Tools to calculate the pressure and temperature dependent iron exchange between minerals, moduli variation across spin transitions, and more are integrated into the BurnMan infrastructure and easily adaptable to the user's specific needs. Example user scripts provide the user a guide to quickly and easily calculate seismic velocities and compare with observed values. Other scripts exemplify the many choices that can be made to customize BurnMan, for example in the choice of EoS, the averaging scheme, or the geotherm. BurnMan is easily scriptable and can be directly used to produce publication quality figures. BurnMan is currently focused on the lower mantle, but as it is offered open-source, it has the potential to expand to other planetary applications. Applications of BurnMan include forward modeling seismic velocities for a geodynamical model with a given composition, comparing models of different bulk Earth composition, and fitting experimental values with an EoS. An advantage of BurnMan is that experimental values can be fit by mineral physical constants, and subsequently these constants can be used with consistent methods and assumptions in the forward problem. Future work includes applying the BurnMan code as the forward model for a Bayesian inversion of seismic velocity models in the lower mantle, applying the latest results from mineral physics, and reasoning that the lower mantle cannot be represented by an average 1D radial seismic model. This collaboration was initiated at the CIDER 2012 summer meeting. Cottaar, S., Heister, T., Rose, I., and Unterborn, C.: BurnMan - A Lower Mantle Mineral Physics Toolkit. In preparation, 2013. Cottaar, S., Heister, T., Rose, I., and Unterborn, C.: BurnMan. Technical Reference, www.burnman.org, 2013.