May 5, 2000

What are lava tubes?

Following a volcanic eruption, lava quickly spreads out from the crater. The surface of the lava cools relatively quickly and solidifies. However, the inner lava may continue to flow rapidly. Once lava ceases flowing from the crater, the remaining liquid lava drains out leaving an empty tube surrounded by a solid crust. This tube is a natural lava tunnel which may be up to 5 meters in width and 10 meters in height. Lava tubes are common on the island of Santa Cruz in the Galapagos.

Listen to Roger Payne's Voice from the Sea piece entitled:
The Geology of the Galapagos Islands

For more information about the geology of the Galapagos Islands, visit Voyage to the Galapagos on PBS Online.

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