2024 Volcano Monthly Calendar! A volcano is a rupture in the Earth's crust that allows lava, ash and gases to escape from magma chambers below the surface. There are around 1500 volcanoes on the Earth's surface, and a further unknown number below the ocean. An eruption can be a dangerous thing, so we're bringing you all of their beauty, without the hazard. Enjoy this beautiful science nature calendar. HIGH QUALITY: Volcano Calendar Size Closed: 12 x 12 Inch. Opened: 12 x 24 Inch. Does not bleed through! 13 Full Color Images in our 2024 Nature Calendar! All photos are hand selected from a wide array of photographers from around the world! No compromises are made on image quality or content color in our 2024 scenic wall calendar.