A tunnel below the surface of a solidified lava flow, formed when the exterior portions of the flow solidify and the molten internal material is drained away.
Lava tubes form when the surface flowing lava congeals forming a crust. The lava underneath the solidified crust continues to flow, now insulated from the cooling air. When the lava eruption ceases, and if the tube drains, a large tubular cave may be left behind.
A tunnel beneath the solidified surface of a lava flow through which lava continues to flow. Also, the hollow space left when the lava within a tube drains away.
A cave in lava formed by removal of liquid material from beneath a solid roof.
a long tunnel whose walls are made of lava rock
a natural hollow tube that lava once traveled through
a relic of a river of molten lava, self-crusted over on the top as the exposed surface cools, and then at least partially voided out as the lava spreads out eventually on the surface as a sheet
a volcanic structure where, as a lava flow hardens at the surface creating a skin, the liquid lava continues to flow through the middle, hollowing out an area creating a tube like structure
Landform. A tunnel formed when the surface a lava flow cools and solidifies, but the molten material under the surface remains fluid and drains away, leaving behind cavities or tubes.
a hollow tube formed when the outer layer of lava is cooled by the air and hardens; molten lava may continue running through the tube.
A tunnel formed when the surface of a lava flow cools and solidifies while the still-molten interior flows through and drains away.
The empty space left when a lava tunnel drains; this happens when the surface of a lava flow solidifies while the inner part of the flow continues to stream downslope.
A hollow space beneath the surface of a solidified lava flow, formed by the withdrawal of molten lava after the formation of the surficial crust. Lava Beds National Monument has many excellent and accessible examples.
A tunnel in a lava flow formed when the surface of a lava stream or channel (similar to a river of lava) cools and freezes and the interior remains hot.
A tunnel formed underneath the surface of a solidfying lava flow.
A lava tube is a tube-like, underground conduit formed by flowing lava. The flowing lava crusts over at the edges and drains out onto lower ground - what is left is a smooth, tube-like tunnel with hanging lava stalactites and a flat floor - a lava tube.
a hollow subterranean channel in a lava flow formed by withdrawal of the lava after solidification of the superficial crust. [AHDOS
Lava tubes are natural conduits through which lava travels beneath the surface of a lava flow, expelled by a volcano during an eruption. They can be actively draining lava from a source, or can be extinct, meaning the lava flow has ceased and the rock has cooled and left a long, cave-like channel.
