When an explosive is detonated, a rapidly expanding gas is created, known as a pressure wave. If the pressure wave is fast enough to break the sound barrier, it generates a powerful shock wave. On land, these shock waves can burn skin, tear limbs apart, and propel objects and shrapnel through the air. But what happens when an explosion occurs underwater?Underwater, the elastic properties of water cause the shock wave to be shorter in duration, but with a proportionally greater maximum overpressure.
This means that the shock wave is more powerful underwater than on land. However, due to the nature of water, the energy of the shock wave attenuates very quickly with range. Sound waves that travel to great depths travel at a minimum speed and are trapped in a layer known as the Sound Fixation and Range Channel (SOFAR). This layer helps to contain the shock wave energy and keep it from dissipating too quickly.
Acoustic waves from underwater events, including explosions, can be picked up over long distances by extremely sensitive devices. If an underwater explosion occurs near a structure, the resulting pressure wave can break the hull and cause significant damage to surrounding equipment. The expansion of plasma induces high pressures that lead to the formation and propagation of shock waves, which produces tension fields within the material. In order to investigate the velocity of the crash front, photographs of stripes are taken by inserting a slit in one direction along the front surface of the crash. When this wave reaches the limit of the explosive material and the surrounding medium, pressure is transmitted across the limit at a finite pressure and velocity. In ocean acoustic tomography, sound waves propagate in predetermined directions across the sea at distances of hundreds to thousands of kilometers.
This has been used to provide information on fronts, turns and other large-scale temperature variations in the sea through tomographic inversions of travel time difference data. A computerized evaluation of experimental data provides a detailed x-t wave ratio for submarine shock waves. It has been shown that for regular reflection from a point of reflection in a wedge, an almost semicircular shock occurs. For Mach reflection, this is combined with a flow of local interaction. Overall, due to its elastic properties, water amplifies shock waves and makes them more powerful than on land. However, due to its nature, shock wave energy attenuates very quickly with range.