Ghost reflections caused by energy initially reflected above the level of the shot

Some experiments are described which demonstrate the occurrence of an initial reflection from above shot level and of a resultant secondary reflection from depth which, by optical analogy, may be termed a ghost reflection. The reflector above shot level was in this case the base of the weathered layer. Reflection coefficients as high as 2/3 were found in the Pleistocene Beaumont clay surface in Harris County, Texas. With reflection coefficients of this magnitude, the ghost reflections influence the character of seismograms noticeably.