An explosion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it; usually this happens when there is confinement around the pressure releasing point
Reference: Gexcon Handbook
Explosion propagating at supersonic velocity and characterized by a shock wave.
Reference: S2S (safety to safety website: ISO 8421-1(1987-03-01, 1.12), EN 1127-1: 1998, EN 1127-2:2002 (E), prEN 14460:2002 (E), EN 13237:2003 (E))
A reactive shock wave: due to the temperature jump associated with the compression of a material of a pure substance or a mixture at the front of a shock wave a reactive substance can decompose exothermally. When reaction is fast enough (reaction zone Chapman-Jouguet condition) the generated energy will in part be used to sustain the shock resulting in a steady state process. Pressure and propagation velocity depend on energy generated, while in condensed substances pressures will be a thousand times higher than in gases.