What happens at a destructive plate boundary where two oceanic plates converge (come together)?

Two oceanic plates are converging and the faster moving or slightly denser one subducts. The basaltic rock of the subducted plate starts to melt and rises through the mantle to form a submarine volcano. Overtime, the submarine volcano builds up in layers and can eventually break through the surface of the ocean to become a volcanic island. An example of this is Guam, the US territory on the western side of the Pacific Ocean. The Pacific Plate is being subducted beneath the smaller Philippine Plate.