Three dimensional modeling of dynamic microstructure

In this project, we continue to develop a new theoretical toolbox, `microgeodynamics', to address the issues of detection of partial melting in the Earth?s interior and dynamics of melt storage and segregation. We will study the influence of melt volume fraction, wetting behavior, and deformation on the physical properties such as elastic moduli and melt mobility using a SemiAnalytical Model (SAM) and a Boundary Elements Model (BEM). The output of these models, dynamic melt geometry, will be processed to explain observed anomalies in various physical properties in the Earth's deep interior.

Small amounts of melting in the silicate part of the Earth's deep interior exert a disproportionate influence on the physical and chemical properties of rocks. Melt is often distributed in tubes, disks, or pockets, whose dimensions are as small as the fraction of the width of a human hair. Relative abundance of these different shapes of melt units depend on both the dynamic environment of melting and chemical composition of the melts. The signature of melt geometry, an averaged description of melt distribution in these various units, is sampled by earthquake waves passing through these regions. Deciphering the signals of these earthquake waves, one can find out about the processes associated with melting in the deep Earth.