A method of inducing fracture in at least a portion of a geologic structure includes inducing acoustic waves into a fluid medium present in a borehole extending at least partially into the structure. Embodiments may include preheating or pressurizing the fluid medium prior to inducing the acoustic wave therein. A device for fracturing at least a portion of a geologic structure includes electrodes for producing a spark to generate ordinary acoustic waves in the fluid medium. Embodiments may include structures for preheating or pressurizing the fluid medium prior to inducing the acoustic wave therein.