Following the 2018 eruption, crack meters were installed in the Nahuku lava tube in 2019 to track rock movements. Photo Credit: NPS/J. Wei
The Nahuku lava tube (also known as Thurston Lava Tube) is closed at Hawaii Volcanoes National Park, and it’s uncertain when it will reopen. One of the few accessible lava tubes in Hawaii, Nahuku was created long ago by an underground river of magma and visitors have frequented the lava tube via a short day hike.
It was closed last week due to movement of an overhead rock slab, which now makes the trail unstable and dangerous. The National Park Service is unsure how long it will take to reopen, as it would require “a return of movement similar to the previous record” before it would be considered safe again. The park will continue to monitor its movements.