The second chapter deals with the fundamental of continuum mechanics. It describes stresses and strains in a continuum. This is followed by fundamental laws of mechanics and constitutive relations. Elasticity and Hooke's law are described. Next, the chapter describes poroelasticity as well as poroplasticity, followed by fracture mechanics. Finally, rock physics models as applied to pore pressure detection are described.

This chapter discusses technologies that yield geologically plausible and physically possible interval velocities from surface seismic data. The workflow is termed RPGVM, rock physics guided velocity modeling. The approach can be used on any algorithm for interval velocity computations – be it conventional or based on inversions such as tomography and FWI. The goal is to define the parameter base associated with a particular inversion approach so that the inferred velocity model is constrained by rock physics and bounds of pore pressure. Applications from the Gulf of Mexico and offshore India are described. The chapter shows the value of rock physics templates for deriving velocity models with anisotropic tomography.