Raytheon has developed a technology for safely detonating all the landmines in disused landmine fields — they drop a shell containing many hundreds of steel arrows into the field, which sets off all the old mines:
Each rod has a flared rear end, like the feathers of an arrow, and hundreds can be packed into a single cylindrical shell. This shell can be lobbed into a mined area and just before impact a charge behind the arrows will fire them downwards. The metal flights will keep the arrows on a straight course so that they pepper the area at high velocity and at regular spaces.
Tests show that a shell containing hundreds of arrows can wipe out every mine in an area several metres square, even when the mines are buried under sand or under nearly a metre of water. GPS can also be used to guide the shells into overlapping patches in order to safely clear a wide area.
(via Worldchanging)