This grant provides partial support for acquisition of a multi CPU PC cluster for geodynamic/seismological modeling by the geophysics group at the University of Colorado. The proposed PC-cluster will be used for a number of computationally intensive NSF/EAR funded projects including 1) Constraining thermochemical mantle convection using plume-related observations (Geodynamics), 2) Sublithospheric small-scale convection and lithospheric evolution (Geodynamics), 3) Formation of very long-wavelength structure in the mantle and its implications for supercontinent formation and breakup (Geodynamics), 4) Ambient noise tomography (Seismology), 5) Monte-Carlo inversion of seismic structure and surface wave tomography (Seismology), and 6) Forward modeling of seismic wave propagation. The PC cluster will help train graduate students and post-docs in the University of Colorado geophysics group in parallel computing and programming through research and teaching. The investigators are actively involved in the Computational Infrastructure for Geophysics (CIG) and newly developed and enhanced software packages will be made freely available the geophysics community through CIG.