One of world’s most iconic sea arches could collapse at any time, Hawaii park says

One of the world’s most iconic sea arches could vanish at any moment, according to the National Park Service.

The 90-foot-tall Hōlei Sea Arch in Hawai’i Volcanoes National Park lost a key part of its base on earlier this week and is now hanging on by a geologic thread, the park wrote July 20 on Facebook.

“It is possible the arch could collapse into the ocean at any time without warning!” park officials said.

“Admire what could possibly be a last look at Hōlei Sea Arch from the safe viewing area away from the cliff edge.”

Before and after photos shared by the park show a large section of rock fell away from the base, leaving what amounts to a very weak ankle holding the arch aloft.

It happened as “historic” 20- to 25-foot swells pounded the island’s southern coast July 17 to 18, driven by the remnants of Hurricane Darby.

Hōlei Sea Arch has long been considered unstable, due to earth cracks and erosion, the park says. Walking atop the arch is forbidden and even the surrounding cliff is considered too steep and dangerous for hiking.

“Sea arches are beautiful, and a temporary part of the ever-changing volcanic landscape,” the park says.

“Hōlei Sea Arch was formed as the Pacific Ocean pounded into an ancient lava flow about 550 years ago. A continued battering of waves and erosion created the shape we see today.”

Hawaii’s southern coast is known for rough and violent surf, which has carved the aging lava rock into caves, cliffs and arches.

Once Hōlei Sea Arch collapses, it could result in a pillar of rocks known as a sea stack.

The park’s Facebook post racked up more than 2,500 reactions and comments as of July 21, many from people who submitted photos of the arch taken on vacations and honeymoons. Some urged the park to set up a camera and record the beloved site’s demise.

“It’s simply awesome and unbelievable it’s still there with the crazy forces of the waves,” Mehul Jariwala wrote.

“This is a favorite stop at Hawai’i Volcanoes National Park for so many,” Lisa Gose-Nelson said.

This story was originally published July 21, 2022 at 6:25 AM with the headline "One of world’s most iconic sea arches could collapse at any time, Hawaii park says."