The Hōlei Sea Arch collapse has erased a 90-foot natural landmark in Hawaiʻi Volcanoes National Park. The arch, which stood on the Big Island’s coast for more than five centuries, fell into the Pacific Ocean, according to the National Park Service. The park announced the news on Oct. 1, though officials said the exact time of the collapse is unknown.
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Hōlei Sea Arch Collapse: What Happened
The National Park Service said the arch was last confirmed standing on Wednesday, Sept. 23, and was gone by Sunday night, Sept. 27. The park was temporarily closed during Tropical Storm Nolo, and officials said the collapse may have happened while the park was closed. Hawaiʻi Public Radio reported that the park did not confirm whether storm conditions contributed.
Dexerto described the arch as a product of differential erosion, in which ocean waves wear away weaker rock and exploit cracks in hardened lava over time.
Why the Hōlei Sea Arch Was Already at Risk
The arch had been weakening for years. According to the park service, earthquakes during the 2018 Kīlauea eruption and summit collapse damaged nearby cliffs. In January 2020, new cracks led officials to close the original viewing area, and a safer viewpoint reopened in March 2020. Later that year, Tropical Storm Darby’s large surf broke off a chunk of the arch’s lower section.
A USGS photograph credited to S. Geiger, published by Hawaiʻi Public Radio, shows the arch intact in 2014.
Safety Warning After the Hōlei Sea Arch Collapse
Park officials are urging visitors to stay out of closed areas and away from unstable cliff edges, which can give way without warning. Social media photos have shown people entering closed sections near where the arch once stood. The park service stressed the risk of falling and drowning in the rough water below.
Sea arches are temporary by nature. Waves keep wearing at the rock until a span collapses, and the cliffs gradually retreat inland. The same forces that carved the Hōlei Sea Arch are still reshaping Hawaii’s volcanic coastline.
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Landmark losses can also bring hope. See our report on new shoots at the Sycamore Gap tree three years on. Planning a trip? Read our look at how United Airlines base fares are changing, and see why the Academy of Natural Sciences museum is ceasing operations.
