Thurston Lava Tube
November 16, 2011
Photographer: 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 harden 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 Maker: NIKON; Camera Model: E995; Focal Length: 8.2mm; Aperture: f/2.6; Exposure Time: 1.000 s; ISO equiv: 400; Exposure Bias: none; Metering Mode: Matrix; Exposure: program (Auto); Flash Fired: No; Orientation: Normal; Color Space: sRGB; Software: Adobe Photoshop 7.0.