Some Lava Flows Build Their Own Pipelines

Flowing lava can build natural pipelines called lava tubes as it cools quickly and forms a hard rock shell on exposed surfaces while molten lava remains inside at a searing 2100° F (1150° C). As the cooling rock confines the liquid lava to a narrow pipeline, the eruption eventually ends and the lava drains out, leaving an empty tube that can be called a cave. Over the last one million years, thousands of lava flows erupting from the volcano here built lava tubes.

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