The 3-D seismic signature of plumes: wavefield effects and experiment optimization

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The detailed seismic imaging of large mantle plumes is one of the major milestones towards understanding mantle convection and the geochemical evolution of the mantle. So far seismic studies have revealed plume conduits of diameter 100 to 200 km. However, details of the 3-D structure of plumes are difficult to investigate using ray-theoretical methods, (quasi-)analytical solutions for simplified plume structures (e.g. cylinders) or long-period information (e.g. from surface waves) only. We propose to carry out an extensive study of the complete 3-D wave field of likely plume structures with the aim of (1) predicting frequency-dependent effects on amplitudes and waveforms of plume-like structures; (2) testing experimental configurations for teleseismic studies on their ability to map the deep plume structure, (3) optimizing experimental configurations for seismic refraction studies planned in the future and (4) develop processing methods to extract structural information from recorded data. The numerical simulations of the 3-D wave fields will be carried out using verified algorithms developed on high-performance computers with the ability to achieve high-frequency wavefields.