Lava Tube Skylights – A Dangerous Beauty:
Lava tube skylights form when part of the roof of a lava tube collapses. In the case of active lava tubes, these skylights allow a glimpse of the gorgeous super heated river of glowing lava below. But hidden danger also lurks beneath their beauty.
Since the crusts of active lava tubes are inherently unstable, collapses like these are fairly common, and may happen suddenly, without warning. That’s just what happened over the past weeks out on the active flow field.
The following photos show the dramatic rate at which this can occur. HVO scientists in the field on the morning of September 30th first noted the small opening to the left pictured below. Just a few hours later the larger right area collapsed as well, eventually forming one large skylight about 16 feet (5 m) across.
Another skylight recently formed farther down on the flow field in the past weeks which our guests have been able to view and photograph using a telephoto lens. Hawai’i Volcanoes National Park rangers have roped off the area adjacent to the tube because of the likelihood of further collapse.
Sulfurous gasses, present along the length of the lava tube, present yet another hazard near skylights.
Besides being beautiful, lava tube skylights are also important to science. They allow scientists to measure the lava volume and flow rate as it changes throughout an eruption. Scientists can measure the speed of the flow using a radar gun (the same kind used to catch speeding motorists). Flow volume in the tube is measure using very low frequency radio waves.
Because of the extreme danger, scientists work very carefully near lava tubes, keeping as far away as possible from their fragile crusts. Nevertheless, accidents do happen…
In 1985, an HVO geologist broke through the crust of an active lava tube while sampling in a remote area and found himself nearly thigh deep in over 2,000 degree lava. Fortunately, he was pulled out in under 5 seconds by another scientist and rushed to a helicopter, which luckily, was just landing nearby. He was wearing a heat resistant suit, which offered some protection, but still sustained first, second and third degree burns. Happily, he made a full recovery, but it’s easy to see how it may not have gone so well.
Because of the extreme danger, Hawai’i Volcanoes National Park rangers have closed the area near these skylights, and to venture into the closed area would be foolhardy. Luckily, it’s still possible to get good views and photos from a safe distance.
The Kamokuna Ocean Entry has been going strong, with many streams of lava entering the ocean. Our guests have been treated to clear starry skies and great viewing conditions over the past week.
Come see it for yourself while it lasts on one of our Lava Bike and Hike Tours