Lanterna Rally

Author: Myung W. Lee

Publisher:

Published: 1990

Total Pages: 34

ISBN-13:

Preserving the relative true-amplitude of seismic traces provides significant advantages for deep crustal investigations, particularly for the identification and analysis of deep reflections originating near the crust-mantle boundary. Preserving lateraI variations along deep reflections is also important for resolving amplitude changes due to geologic causes rather than to artifacts from recording or source conditions. Three relative true-amplitude processing methods (automatic edit, single-trace equalization, and a common-depth-point gather equalization) were applied to the 20-second seismic data of the Great lakes Multidisciplinary Program on Crustal Evolution in order to evaluate the performance of the different techniques. Particular attention was paid to the improvement of signal-to-noise ratio and to the preservation of latera I continuity of the deep reflections. This study indicates that the automatic editing procedure based on the median amplitude of a common-depth-point gather provided substantial signal-to-noise ratio improvement of the seismic profiles. Post-stack amplitude balancing was commonly necessary to maintain the lateral continuity of the deep reflections and to reduce migration noise. The results from these processing strategies confirm the existence of large differences in crustal reflectivities and in the shape and geometry of crust-mantle transition beneath central and western lake Superior.