Subsidence of geologic surface structures due to withdrawal of fluids from aquifers and petroleum reservoirs is a phenomenon experienced throughout the world as the demand for water and hydrocarbons increases with increasing population growth. This book addresses the definition and theories of subsidence, and the influences of unique conditions on subsidence; it includes discussions of specific field cases and a basic mathematical model of reservoir compaction and accompanying loss of porosity and permeability. The book is designed as a reference for readers giving immediate access to the geological events that establish conditions for compaction, the mathematical theories of compaction and subsidence, and practical considerations of field case histories in various regions of the world.