550-year-old rock arch collapses into sea

Hawaii’s famous Hōlei Sea Arch, a 90ft (27.4m) lava-rock formation that formed about 550 years ago, has collapsed into the Pacific Ocean.

The exact time of the collapse is unknown, Grace Eliza Goodwin reported for the BBC.

The arch was still projecting into the water off the coast of Hawaiʻi Volcanoes National Park on 23 September but had disappeared by 27 September, the National Park Service (NPS) said.

The NPS said the coastline flanking the arch had shown signs of instability for years.

Located at the end of Chain of Craters Road on the island of Hawaiʻi, also known as the Big Island, the formation was a popular and heavily photographed tourist attraction.

The arch is believed to have fallen while the park was temporarily closed during Tropical Storm Nolo at the weekend.

Hawaiʻi Public Radio reported that claims the arch had disappeared began circulating on social media after the park reopened on Sunday. The park confirmed the collapse in a Facebook post on Wednesday but did not say whether storm conditions had contributed to it.

The park service said earthquakes during the 2018 Kīlauea eruption and summit collapse had damaged the cliffs near the arch. In January 2020, new cracks and signs of instability in the cliffs led the park to close the original viewing area. A few months later, a new viewing area opened at a safer distance.

Waves from a tropical storm later that year broke a chunk of rock from the bottom of the arch, the NPS said.

The NPS warned in 2021 that the arch would eventually crumble into the sea, saying the formation was beautiful but temporary, with a limited lifespan, and that other arches would replace it as the cliff slowly migrated inland.

It described the collapse as the latest transformation of the park’s remote and rugged coastline.