GEOLOGY

Detailed explanation-1: -Magma formed above a subducting plate slowly rise into the overriding crust and finally to the surface forming a volcanic arc, a chain of active volcanoes which parallels the deep ocean trench.

Detailed explanation-2: -Deep trenches are features often formed where tectonic plates are being subducted and earthquakes are common at subduction zones as well. As the sinking plate moves deeper into the mantle, fluids are released from the rock causing the overlying mantle to partially melt.

Detailed explanation-3: -Volcanoes form here in two settings where either oceanic plate descends below another oceanic plate or an oceanic plate descends below a continental plate. This process is called subduction and creates distinctive types of volcanoes depending on the setting: ocean-ocean subduction produces an island-arc volcano.

Detailed explanation-4: -Subduction zone volcanism occurs where two plates are converging on one another. One plate containing oceanic lithosphere descends beneath the adjacent plate, thus consuming the oceanic lithosphere into the earth’s mantle. This on-going process is called subduction.