Hōlei Sea Arch at Hawai'i Volcanoes National Park collapses after storm surge
The 90-foot Hōlei Sea Arch in Hawai'i Volcanoes National Park fell between Sept. 23 and early October, likely accelerated by recent tropical storm activity, prompting safety warnings for visitors.
The National Park Service announced that the Hōlei Sea Arch, a 90-foot natural rock formation at Hawai'i Volcanoes National Park on the Big Island, collapsed sometime between Sept. 23 and early October, coinciding with high surf from Tropical Storm Nolo.
The agency said the exact timing of the collapse is unknown and may have occurred while the park was temporarily closed during the storm. It warned visitors to stay away from the unstable coastal cliffs, which drop vertically into the ocean and pose a risk of falling or drowning.
Park officials noted that the arch, formed from roughly 550-year-old lava flows and shaped by ocean erosion, had shown signs of weakening for years. Cracks appeared in early 2020, leading to the relocation of the viewing area farther from the shoreline. In 2020, surf from Tropical Storm Darby broke off a portion of the arch’s lower section.
The U.S. Geological Survey described the arch as a product of differential erosion by ocean waves, explaining that continual wave action gradually removes material from the basalt structure until it eventually collapses.