UPPER MANTLE STRUCTURE IN CANADA FROM SEISMIC OBSERVATIONS USING CHEMICAL EXPLOSIONS

• Published in: Canadian Journal of Earth Sciences
• Main Author: Barr, K. G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1967
• Subjects: General Earth and Planetary Sciences; Hudson Bay; Canada; Hudson
• Online Access: http://dx.doi.org/10.1139/e67-066; http://www.nrcresearchpress.com/doi/pdf/10.1139/e67-066

Long-range seismic observations at the standard Canadian seismic stations, from chemical explosions in Hudson Bay and Lake Superior, are used to derive a P-wave velocity structure for the upper mantle. The coordinates of observed cusps are used to define the structural discontinuities. These discontinuities are at depths of 126 and 366 km, which agree closely with the depths of the S-wave velocity discontinuities deduced from surface-wave observations. The observations do not require a low velocity layer in the upper mantle.