DEEP CRUSTAL REFLECTION RECORDINGS USING “VIBROSEIS” METHODS—A FEASIBILITY STUDY

Publisher Website
Google Scholar
Abstract
This work on deep crustal reflections started in 1972. Possibilities for improvement in signal quality were noted and, in 1973, were incorporated in a new experiment. All work was done with 15.0–2.0 hz or 20.0–5.0 hz swept frequency signals 30 sec long. On most occasions, 240 sweeps were used—all recordings of each trace were added together. In order to further improve the signal/noise, six large vibrators, spaced closely together along a line at right angles to the source‐receiver line, were used simultaneously. The basic detector was an 8‐arm star, with radius 300 ft, each arm containing thirty 4.0 hz geophones. Two very good refraction events were recorded; they came from velocity discontinuities at depths of only a few thousand feet. Other long delayed energy, which might be deep crustal reflections, was observed. Due to the lack of complete subsurface coverage and possibly due to complexity of the structure, these events cannot be certainly identified as reflections.

This publication has 0 references indexed in Scilit: