Scientist takes advantage of a skylight to measure height of lava
flowing in a lava tube, Kilauea Volcano, Hawai`i.
Photograph by K.V. Cashman in
1994
Skylight
A skylight is an opening in the roof of a lava tube. Skylights
usually form when part of the roof collapses into the tube, but
they also occur where a roof failed to form over the lava
channel. If the tube is active, a stream of glowing lava can
be seen moving below.