GEOLOGY

Detailed explanation-1: -On the subducting side of the island arc is a deep and narrow oceanic trench, which is the trace at the Earth’s surface of the boundary between the down-going and overriding plates. This trench is created by the downward gravitational pull of the relatively dense subducting plate on the leading edge of the plate.

Detailed explanation-2: -If two tectonic plates collide, they form a convergent plate boundary. Usually, one of the converging plates will move beneath the other, a process known as subduction. Deep trenches are features often formed where tectonic plates are being subducted and earthquakes are common at subduction zones as well.

Detailed explanation-3: -intraoceanic arcs (primitive arcs) form when oceanic crust subducts beneath other oceanic crust on an adjacent plate, creating a volcanic island arc. continental arcs form when oceanic crust subducts beneath continental crust on an adjacent plate, creating an arc-shaped mountain belt.

Detailed explanation-4: -This process is called subduction. A deep ocean trench forms at this subduction boundary. As the subducting plate plunges deep into the mantle, it gets so hot it melts the surrounding rock. The molten rock rises through the crust and erupts at the surface of the overriding plate.

Detailed explanation-5: -Islands form an arc when two oceanic plates converge creating a row of islands above the overriding plate. The older plate, which is heavier and denser, is forced beneath the lighter plate. The subducting plate begins to heat up as it descends into the lithosphere and eventually melts .