Much has changed since SEG published a comprehensive book on multicomponent seismic technology in 1991. The current volume, Multicomponent Seismic Technology (SEG Geophysical References Series No. 18) updates the subject. Emphasis is placed on practical applications of multicomponent seismic technology, with chapters dedicated to data-acquisition procedures, data-processing strategies, techniques for depth-registering P and S data, rock-physics principles, joint interpretations of P and S data, and numerous case histories that demonstrate the value of multicomponent data for evaluating onshore and off-shore prospects. All forms of multicomponent seismic data are considered - three component, four component, and nine component. Interpretation focuses on elastic wavefield seismic stratigraphy, in which a seismic interpreter gives the same weight to S-wave data as to P-wave data when defining seismic sequences and seismic facies. S-wave splitting in fractured media and other key theoretical concepts are supported by numerous data examples. The book will be of interest to researchers in multicomponent seismic technology and to explorationists who have to locate and exploit energy resources. The book will be appreciated by those who shun mathematical theory because it explains principles and concepts with real data rather than with mathematical equations.