Much of the work is basic physics. Application of the revised model at ambient conditions to new IR data on dense phases revealed that k for olivine is doubled upon its high-pressure transformation to the spinel structure. Modeling the slab with this information yielded higher internal temperatures, significantly reducing the likelihood of metastable olivine or of kinetics being important for deep earthquakes. To understand the effect of chemical composition on the k , undergraduate Paul Giesting has applied the model to garnets.
Calculations match available measurements, and suggest majorite has low k .
Our current focus is on majorite, due to its volumetric importance to the transition zone, and on the radiative contribution, due to a misunderstanding in the geologic literature of the differences between ballistic and diffusive processes. Dust in Space Astronomical measurements of infrared spectra show signatures of dust superimposed upon stellar emissions. A first step in understanding the development of protoplanetary nebula is simply identification of the dust that exists in space. To achieve this end, my research group is collecting IR reflectivity spectra and thin film data of about 100 minerals thought to be part of the condensation sequence, or identified in meteorites, and various simple chemical compounds. Quantitative analyses of these data provide optical functions and emission spectra, which can be used to infer grain sizes, in addition to chemistry and structure.