Unique equipment for low-frequency laboratory measurement of seismic wave speeds and attenuation has recently provided new insights into the frequency, temperature and grainsize sensitivity of seismic wave speeds and attenuation in fine-grained synthetic specimens of the dominant upper-mantle mineral olivine.
The possible role of crystal defects known as dislocations, generated by prior/ongoing deformation, in seismic-wave attenuation was the focus of the recently completed Ph. D. project of Robert Farla. The next exciting frontier is the possible enhancement of such non-elastic effects by small amounts of water accommodated as defects within the olivine crystal structure.
This work, being undertaken in collaboration with Professors Uli Faul of Boston University (BU) and Shun Karato of Yale University, provides opportunities for students to work at both ANU and overseas at BU or Yale on the preparation, characterisation and mechanical testing of such materials and the development of strategies for modelling and seismological application of the results.