GEOLOGY

Detailed explanation-1: -Destructive, or convergent, plate boundaries are where the tectonic plates are moving towards each other. Volcanoes form here in two settings where either oceanic plate descends below another oceanic plate or an oceanic plate descends below a continental plate.

Detailed explanation-2: -Mid-oceanic ridges are plate boundaries where new oceanic crust is created. The mid-ocean ridge system is an example of a divergent (rather than a convergent or transform) plate boundary. Himalayan Mountains are a convergent plate boundary: Fig.

Detailed explanation-3: -Although most of the active volcanoes we see on land occur where plates collide, the greatest number of the Earth’s volcanoes are hidden from view, occurring on the ocean floor along spreading ridges.

Detailed explanation-4: -At a convergent plate boundary, when one plate is oceanic, there are large volcanoes. These volcanoes are found in lines that outline the subduction zone. Earthquakes also happen in these zones. The Aleutian Islands that border southern Alaska are an island arc.