volcanic landform definition
1. a. An opening in the earth's crust from which lava, ash, and hot gases flow or are ejected during an eruption. b. A similar opening on the surface of another celestial object. 2. A usually cone-shaped mountain formed from the materials issuing from such an opening.n opening in the Earth's crust from which lava, ash, and hot gases flow or are thrown out during an eruption. 2. A usually cone-shaped mountain formed by the materials that flowed or were thrown out from such an opening. See more at tectonic boundary.