1. ISLAND ARCS

3. Island Arc Formation
As a lithospheric slab is being subducted, the slab melts when the edges reach a depth which is sufficiently hot.
Hot, remelted material from the subducting slab rises and leaks into the crust, forming a series of volcanoes.
These volcanoes can make a chain of islands called an "island arc". Examples of island arcs are the Japanese islands and the Kuril Islands which occurs on the North American Plate.

4. This is an image of the ocean floor of the Earth, showing island arcs being formed.