The subject of this NATO Advanced Study Institute was seismic monitoring under a nuclear test ban - an application of scienti­ fic knowledge and modern technology for a political purpose. The international political objective of a comprehensive nuclear test ban provided in turn the motivation for our technical and scientific discussions. In order to obtain a historical perspec­ tive on the progress of the work towards a comprehensive test-ban treaty (CTB), it is necessary to go back to 1958, when a confer­ ence of scientific experts in Geneva made the first steps toward an international seismic monitoring system. However, agreement on actual capabilities of a monitoring system for verifying compliance with such a treaty was not achieved, and thus the conference did not lead to immediate political results. After the Partial Test Ban Treaty of 1963, which banned nuclear explosions in the atmosphere, outer space and under the seas, renewed interest in the seismological verification of a CTB took place. A number of countries initiated large-scale research efforts toward detecting and identifying underground nuclear explosions, and it was in this context that the large­ aperture seismic arrays NORSAR and LASA were established. This type of development resulted in excellent seismic data in digital form and was thus of great irnprotance to the seismological com­ munity.

Inhalt

Seismic Source Identification: A Review of Past and Present Research Efforts.- Earthquake Source Modelling.- The Nature of the Earthquake Source.- Dynamics of Seismic Sources.- Explosion Source Modelling.- Inelastic Processes in Seismic Wave Generation by Underground Explosions.- Anomalous Rayleigh Waves from Presumed Explosions in East Kazakh.- P Wave Coupling of Underground Explosions in Various Geologic Media.- Seismic Source Parameter Estimation.- Seismic Moment Tensors.- Determination of Source Mechanism and Hypocentral Coordinates from Waveform Data.- The Effect of Green's Functions on the Determination of Source Mechanisms by the Linear Inversion of Seismograms.- Simplified Bodywave Source Terms with One Application in Moment Tensor Recovery.- The Interpretation of Moment Tensor Inversions.- Seismic Wavefield Synthesis.- Coupling Near Source Phenomena into Surface Wave Generation.- On Seismic Synthesis.- Some Recent Extensions of the Reflectivity Method.- Isochronal Formulation of Seismic Diffraction.- High Frequency Toroidal Modes.- Elastic and Electromagnetic Wave Propagation in Horizontally Layered Media.- Calculation of Wave Fields in Mantle Velocity Models.- The Effect of Focal Depth and Source Type on Synthetic Seismograms.- Seismic Wave Analysis.- Surface Wave Propagation Across Different Tectonic Regions.- Lg Wave Propagation in Eurasia.- Seismograms of Explosions at Regional Distances in the Western United States: Observations and Reflectivity Method Modeling.- Phase Identification and Event Location at Regional Distance Using Small-Aperture Array Data.- P and S-Velocity Jump at the Inner-Core Boundary from PKP Amplitudes.- Conversion Phases from Mantle Transition Zones.- The Excitation and Attenuation of Seismic Crustal Phases in Turkey.- Comparison of Waveform Inversion Schemes for Horizontally Stratified Media.- Scattering and Earth Heterogeneities.- Attenuation and Scattering of Short-Period Seismic Waves in the Lithosphere.- Source Location in Laterally Varying Media.- Optimum Approaches to Magnitude Measurements.- Three-Dimensional Seismic Velocity Image of the Upper Mantle Beneath Southeastern Europe.- Tau Inversion of Upper Mantle Array Data with Application to the Problem of the Scattering of Seismic Waves in the Lithosphere.- Observation of Scattering in the Lithosphere.- Lateral Variations in the Earth's Crust and their Effect on Seismic Wave Propagation.- Signal Analysis.- Fundamentals of Multidimensional Time-Series Analysis.- The Instantaneous Amplitude, Phase and Frequency in Seismic Event Detection, Timing and Identification.- Seismic Source Discrimination.- Multidimensional Discrimination Techniques - Theory and Application.- Seismic Discrimination Problems at Regional Distances.- Linear Discrimination for Samples of Limited Size.- Developments in Seismic Instrumentation.- The Global Digital Seismograph Network: A Status Report.- Broad-Band Seismometry - A Unified Approach Towards a Kinematic and Dynamic Interpretation of Seismograms.- Seismic Data Centers.- Automatic Processing Methods in the Analysis of Data from a Global Seismic Network.- International Seismological Data Center. Demonstration Facilities in Sweden.- Design and Development of a Seismic Data Center.- Evaluation of Seismic Network Capability for Event Location.- Appendix Scientific Directors, Lecturers, Participants.- Name Index.