The inner cliff is about 20 m high. When overflowing, the cliff and throat of the vent are completely covered by active lava. Photo taken Oct. 2, 1997. The flows are encased within lava tubes for most of their length and are visible only through skylights in the roof of the tube. Skylight into lava tube.
Skylights are locations where weakened roof of the lava tube collapses, opening the tube to view.
The lava stream within the tube is moving toward the camera at a rate of about 3 meters per second. It travels down-tube 10 km across the flowfield, cooling only a few degrees in route to the shoreline. Photo taken Oct. 2, 1997. The tubes discharge their lava at the shoreline. The hot lava, about 1150 degrees Celsius when it reaches the ocean, generates thick plumes of steam upon contact with seawater.