This book is a paperback reprint of Advances in Geophysics, Volume 35 (1994, Academic Press). It provides an overview of the dramatic progress made in illuminating the properties of deep slabs and the surrounding mantle since the introduction of the plate tectonics model to the earth sciences more than 25 years ago. The thermal and chemical characteristics of the subducted lithosphere are determined through thermal and petrological modeling, with seismological observations providing critical constraints on model parameters. Down-wellings of the oceanic lithosphere play a critical role in plate tectonics by recycling to the mantle material that has risen at mid-ocean ridges and cooled at the earth's surface. To assist future efforts in developing detailed thermal and petrological models of oceanic lithosphere down-wellings, this volume includes a comprehensive review of seismological observations and models. A range of seismological procedures are considered, from travel time constraints on seismic velocity anomalies in the subducting lithospheric slabs, to wave conversions and reflections off internal and external slab boundaries. An extensive reference list will be useful to earth science researchers and seismological specialists as a directory to most of the critical literature on slab structure.

• Provides a comprehensive, chronological summary of seismological studies of slab structure
• Reviews 25-year history of progress in the field
• Distills the many contributions that provide a foundation for mastering the roots of the ideas and observations underlying todays paradigms
• Includes an extensive bibliography
• Effectively organized for course presentation