Usually, one of the converging plates will move beneath the other, which is known as subduction. Deep trenches are often formed where tectonic plates are being subducted and earthquakes are common. As the sinking plate moves deeper into the mantle, fluids are released from the rock causing the overlying mantle to partially melt. The new magma (molten rock) rises and may erupt violently to form volcanoes, often building arcs of islands along the convergent boundary
A. As two oceanic plates come together, one plate may sink and slide beneath the other causing underwater volcanoes to form. The volcanoes will build up and gradually extend above the water’s surface forming islands.
Explanation
The Islands are formed through the subduction process where the oceanic and continental plates converge. The dense and less thick oceanic plate is forced under the continental plate. The plate gets hotter the deeper it is pushed. When the plate reaches a depth facilitating the melting point, a molten rock is formed and it rises to the surface as forming a new volcano on the continental plate.
