It’s been closed for nearly two years, but Hawai‘i Volcanoes National Park’s Nāhuku – otherwise known as Thurston Lava Tube – has finally reopened to the public. 

Hawaii Volcanos National Park's Nāhuku-Thurston lava tube
On Hawaii Island, a popular lava tube has finally reopened, nearly two years after an earthquake and volcanic eruptions forced its closure © National Park Service/Janice Wei

A popular walk-through natural attraction on the Big Island, the tube has been closed since May 2018, after a major earthquake sparked volcanic eruptions that led to the collapse of Halema‘uma‘u, the volcano’s summit crater, and Kīlauea caldera, rendering the lava tube unstable.

Now, Nāhuku is open 24 hours a day and lit from 8 am to 8 pm. Flashlights, headlamps, and extra batteries are recommended on either side of that window, and park officials suggest exploring before 9 am or after 4 pm.

Rangers examine delicate ‘ōhi‘a tree roots
While humanity was away, the long roots of the ‘ōhi‘a trees above the tube grew down through the ceiling, touching the floor in some places © National Park Service/Janice Wei

“We are overjoyed that we can again welcome visitors back to Nāhuku,” Hawai‘i Volcanoes National Park acting superintendent Rhonda Loh said in a press release. “We appreciate the public’s understanding and support during this long road to recovery following the intense volcanic activity of 2018, and urge everyone to be mindful of potential risks when entering any lava tube.”

Between 30 April and 4 August, 2018, 60,000 earthquakes shook Kīlauea – alongside Mauna Loa, one of the park’s two volcanoes and one of the five that make up the Island of Hawaiʻi.  The subsequent eruption wreaked havoc: giant lava flows destroyed hundreds of homes outside of the park, and within its gates, the summit area sustained permanent damage.

A worker replacing the electric line inside the lava tube.
The electric line inside the lava tube had to be replaced © National Park Service/Janice Wei

The eruption impacted the lava tube in a serious way, dislodging large rocks from the ceiling and creating new cracks where none had appeared previously. So to prepare for Nāhuku’s reopening, the National Park Service enlisted specialists, including a geomorphologist and a mining engineer, to make sure it was safe, installing crack monitors, clearly marking low-hanging rocks, improving drainage, and replacing the electrical line to the bathroom. Above ground, the parking situation was reconfigured, adding passenger loading and unloading zones and accessible spaces. 

Visitors will notice other changes within the lava tube as well. “Long, delicate roots from ‘ōhi‘a trees that grow on top of the lava tube grew down through the ceiling to touch the floor in some areas. There are also large colonies of white microbial matter on the lava tube walls,” the NPS press release says, urging guests to resist the temptation to touch. “These unique natural features have likely reappeared due to the absence of people for more than a year.

Rangers examine ohia tree roots, with the cave roof illuminated
Park officials urge visitors to refrain from touching the ‘ōhi‘a tree roots © National Park Service/Janice Wei

Park officials have good reason to be wary. Nāhuku translates as “the protuberances” – likely a reference to the lava stalactites, no longer in evidence thanks to overeager souvenir collectors, that once covered the tube’s ceiling. (Its non-Hawaiian namesake is Lorrin Thurston, a local newspaper baron who “discovered” the tube, advocated for the creation of the national park, and played a key role in overthrowing the Hawaiian monarchy.)

Though the lava tube and much of the park have finally reopened, several areas and attractions remain out of commission – Crater Rim Drive and Crater Rim Trail are currently under repair, while Jaggar Museum and the US Geologic Survey’s Hawaiian Volcano Observatory both still have significant safety issues. 

For more information, check for closures and reopenings at nps.gov.

Read more: 

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