How island arcs are the result of processes at destructive plate boundaries

How island arcs are the result of processes at destructive plate boundaries: 

• Volcanic islands that form parallel to ocean trenches in subduction zones. 
• e.g. pacific ring of fire.

1. Two oceanic plates converge,

2. Older, heavier+denser plate forced beneath lighter plate,

3. Descending plate begins to melt, feeding magma chambers that erupt on the ocean floor of the overiding plate to form volcanic islands, 

4. Islands form parallel to ocean trenches on the overiding plate.  

Examples of island arcs: 

Island arcCountryTrenchBasin or marginal seaOverriding PlateSubducting plate Aleutian Islands United States Aleutian Trench Bering Sea North American Plate Pacific Plate Kuril Islands Russia Kuril–Kamchatka Trench Sea of Okhotsk North American Plate Pacific Plate Japanese Archipelago Japan Japan Trench、Nankai Trough Sea of Japan North American…