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

ISBN-13: 9781468478693 / Angielski / Miękka / 2013 / 184 str.

Irina P. Kosminskaya

Opis

Deep seismiC sounding was proposed by G. A. Gamburtsev and developed under his guid- ance during the period 1948-1955 at the Institute of Physics of the Earth of the Academy of Sciences of the USSR. During that period also, the first geophysical results concerning the deep structure of the earth's crust in several regions in Tien-Shan, the Pamir, and Turkmenia were observed. Beginning with 1956, the deep seismic sounding method has been used widely by geo- physical research groups as well as by geophysical service organizations for regional studies in the USSR. Descriptions of this work have been given in reports by Yu. N. Godin, V. V. Fedynskii, D. N. Kazanli, and others. New variants of the deep seismic sounding method have been developed; continuous profiling (Yu. N. Godin, and others), and point soundings (N. N. Puzyrev, and others). Deep seismic soundings have been carried on outside of Russia also, and studies have been carried out on the use of the deep seismic sounding method in marine applications (E. I. Gal'perin, S. M. Zverev, 1. P. Kosminskaya, Yu. P. Neprochnov, and others). OVer the past decade, the deep seismic sounding method has joined the suite of geo- physical studies as a highly detailed method for studying the earth's crust and upper mantle to depths of 50 to 100 km on land, and of 15 to 25 km in the deep oceans.

Spis treści

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.