MOAB and MOP—the USAF’s two options for big non nukes
Recently, the USAF dropped the MOAB (Massive Ordinance Air Blast or GBU-43) against insurgents in Afghanistan. The weapon works, as its name implies, by detonating a huge explosive charge just above ground. The blast creates a shock wave called overpressure (a 10 psi overpressure will destroy all but concrete buildings). Once related by parachute extraction on a pallet from its MC-130E Combat Talon steering vanes steer the device to its target. Obviously, air supremacy is required for use of the MOAB. It is the largest non-nuclear bomb used in hostile action to date.
That is for above ground and in the presence of air supremacy. The USAF also has a massive weapon for below ground use and when the fight for air supremacy is on—such as the onset of hostilities when elimination of command and communication bunkers is desired. Hence the MOP (Massive Ordinance Penetrator or GBU-57) which outweighs the MOAB by 8400 pounds, is also non-nuclear and can be delivered by a B-2 stealth bomber. Like the MOAB it also has winglets, steering vanes and GPS for accuracy. Unlike the MOAB, the MOP is designed to penetrate as far as 200 feet into the ground prior to detonation.