Direct measurement of ultrasonic Stoneley waves

Abstract

Stoneley waves have long been assumed to exist between rock strata deep within the earth’s crust. We report the first direct measurements of Stoneley waves, in this case generated at 8 MHz and propagated along nickel-Pyrex and other interfaces. The optically measured wavelengths agree with calculated values within 1%. The waves are not detected between unsuitable material pairs. Possible applications are suggested.