An efficient and general approach for implementing thermodynamic phase equilibria information in geophysical and geodynamic studies

Abstract

Abstract. We present a flexible, general and efficient approach for implementing thermodynamic phase equilibria information (in the form of sets of physical parameters) into geophysical and geodynamic studies. The approach is based on multi-dimensional decomposition methods, which transform the original multi-dimensional discrete information into a separated representation that contains significantly less terms, thus drastically reducing the amount of information to be stored in memory during a numerical simulation or geophysical inversion. Accordingly, the amount and resolution of the thermodynamic information that can be used in a simulation or inversion increases substantially. In addition, the method is independent of the actual software used to obtain the primary thermodynamic information, and therefore it can be used in conjunction with any thermodynamic modeling program and/or database. Also, the errors associated with the decomposition procedure are readily controlled by the user, depending on her/his actual needs (e.g. preliminary runs vs full resolution runs). We illustrate the benefits, generality and applicability of our approach with several examples of practical interest for both geodynamic modeling and geophysical inversion/modeling. Our results demonstrate that the proposed method is a competitive and attractive candidate for implementing thermodynamic constraints into a broad range of geophysical and geodynamic studies. MAT-LAB implementations of the method and examples can be downloaded from [link].

3‐D multiobservable probabilistic inversion for the compositional and thermal structure of the lithosphere and upper mantle: III. Thermochemical tomography in the Western‐Central U.S.

“…While our crustal model is consistent with all the inverted data sets, it is clear from the above discussion that more detailed investigations, including receiver function analyses and thermodynamic modeling, are needed to elucidate the thermochemical nature of the crust in this region and the root causes for current discrepancies among different studies. We are currently working on this [e.g., Afonso et al , ], and the results will be presented in a forthcoming publication.…”

The crustal structure of the Arizona Transition Zone and southern Colorado Plateau from multiobservable probabilistic inversion

“…Additionally, the effect of water content, pressure and temperature on the physical properties of crustal rocks cannot be easily addressed by such relationships. Our method has the potential to consider more realistic phase equilibria constraints [Jagoutz and Behn, 2013;Guerri et al, 2015] to better address the effect of composition, water content, Geochemistry, Geophysics, Geosystems 10.1002/2016GC006463 temperature, and pressure on velocity and density of crustal rocks [see, e.g., Afonso et al, 2015]. We expect that this improvement, together with a full 3-D inversion including gravity anomalies and gravity gradients, will help clarify some remaining ambiguities.…”

Numerical modelling of multiphase multicomponent reactive transport in the Earth’s interior

“…These properties in turn are used in the solution of the governing balance equations, and therefore the mechanical and chemical problems are tightly coupled and thermodynamically consistent. We will also demonstrate that a judicious combination of the dynamic and static coupling approaches, based on phase equilibria computations, is not only desirable, but computationally efficient (see also Afonso et al, 2015).…”

“…precomputed properties) elsewhere in the domain. Such a combination of dynamic and static approaches can significantly reduce the computation time associated with the minimization problem, especially when tensor-rank decompositions are used for the static approach (Afonso et al, 2015).…”