Cartesian tensors; stress; strain and deformation; Eulerian and Lagrangian descriptions of motions; conservation principles, Cauchy's equation of motion; constitutive relations, elasticity, plasticity, linear and nonlinear viscous fluid flow; elastic wave equation and Navier-Stokes equation; similarity, scaling and nondimensionalisation of governing equations. Applications from geophysics, materials science, oceanography, and atmospheric physics. Note: credit may only be obtained for one of PHYS 467 and PHYS 567.