what causes a volcano to take on a particular shape?
A volcano is simply an area where magma, or molten rock, from the earthâs mantle reaches the earthâs surface, becoming lava. Most volcanoes occur at plate boundaries, where two plates are moving away (diverging) or together (converging). A few volcanoes like the Hawaiian Islands form from a hot spot, or a weak spot in earthâs crust, where magma forces its way to the surface.