Deep Seismic Sounding of the Earth’s Crust and Upper Mantle

Abstract

I Deep Seismic Sounding and Its Relation to Other Seismic Methods.- 1. Development of Crustal Studies and Deep Seismic Sounding.- 2. The Role of Deep Seismic Sounding among Other Seismic Methods.- 3. Primary Methods of Studying the Crust and Upper Mantle.- 4. Stages in the Development of Deep Seismic Sounding.- II Signals and Their Frequency Content.- 1. Recorded Frequencies.- 2. Shooting Efficiency.- 3. Shot Spectra on Land and at Sea.- 4. Effect of Attenuation in the Crust on the Spectrum of Deep-Traveling Waves.- 5. Spectra of Microseisms and Optimum Frequency Bands.- 6. Signals Recorded in Deep Seismic Sounding and in Seismological Profiling.- III Field Techniques and Resolution in Deep Seismic Sounding.- 1. Recording Layout.- 2. Areas for Recording the Principal Groups of Deep-Travelling Waves.- 3. Optimum Ranges for Recording Deep Reflections.- 4. Resolution in Deep Seismic Sounding.- 5. Applicability of Deep Seismic Sounding and Seismological Profiling to Subdivision of the Earth's Crust.- IV Wave Propagation and Models for the Medium.- 1. Properties of Records, Identifiable and Correlatable Waves for Various Forms of Profiling.- 2. Nature of the Wave Field.- 3. Types of Waves.- 4. Interference Zone in the Vicinity of the Critical Point.- 5. Models of the Crust.- V Wave Propagation in Crusts of Various Types.- 1. Characteristics of Wave Propagation for the Principal Crustal Types.- 2. Regional Classification by Seismic Wave Fields.- 3. Summary Travel Time Curves for Various Tectonic Zones in a Continental Crust.- VI Types and Structures of the Crust.- 1. New Ideas on the Structure of the Earth's Crust and Upper Mantle.- 2. Average Velocity Characteristics for the Crust and the M-Discontinuity.- 3. Types and Structures of the Crust of Various Orders.- 4. Nature and Cause of Layering in the Crust and Upper Mantle.- Conclusions.- 1. The Deep Seismic Sounding Method.- 2. Relationship of Deep Seismic Sounding to Other Methods.- References.