Abstract
A high fidelity recording system has been used to observe the elastic wave motion at vertical separations from an exploding charge ranging from 15 to 300 feet. The motion near the charge has a predominant frequency of about 1000 cps for rigid material and a duration of a few milliseconds. The motion becomes increasingly complex and low frequency components become dominant as the point of observation recedes from the source. A secondary wave which may be a bound wave associated with the fluid in the drill hole was observed.