Thurston Lava Tube

November 16, 2011

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: Rick Stankiewicz
Summary Author: Rick Stankiewicz

The Thurston Lava Tube, shown above, is located in the Hawaii Volcanoes National Park, on the Big Island of Hawaii. Here, you can take a unique walk into an easily accessible, well-lit tube of hardened lava. Lava tubes are like natural pipelines through which lava travels beneath the surface after being expelled by a volcanic eruption. Thicker, slower-moving lava exposed to the air solidifies, forming the ceiling and walls of the tube. The interior channel is kept open by the insulating effect of the hardened layer and by the quickly flowing lava within. Once lava ceases to flow, the rock then cools and leaves a cave-like channel -- similar to a hose once water is shut off. Horizontal markings, called benches or ledges, along the wall of the tube indicate the levels at which lava flowed for a period of time as its supply diminished. It's thought that this lava tube stopped flowing about 500 years ago. Photo taken on February 5, 2006.

Photo Details: Camera: NIKON E995; Focal Length: 8.2mm; Aperture: f/2.6; Exposure Time: 1.000 s; ISO equiv: 400; Software: Adobe Photoshop 7.0.