Hōlei Sea Arch collapses into the Pacific after 550 years

The collapse of a landmark

Hawaii's Hōlei Sea Arch, the 90-foot-tall (27.4-metre) lava rock formation that stood on the southern coast of the Big Island for more than five centuries, has collapsed into the Pacific Ocean.

The National Park Service confirmed the collapse following a series of intense tropical storms that have battered the region in recent weeks. No one saw the exact moment the arch crumbled. It was still standing on Wednesday 23 September, just before Volcanoes National Park was closed ahead of Tropical Storm Nolo. By the night of Sunday 27 September, it had vanished.

A history of instability

Located at the end of the Chain of Craters Road, the arch was one of the park's most popular and photographed sights. It was formed about 550 years ago as ocean waves gradually carved through ancient lava flows, eroding weaker pockets of rock to leave a dramatic bridge over the water.

But its destruction had been anticipated for years. The cliffs flanking the arch had grown increasingly unstable under the strain of both volcanic activity and severe weather.

In 2018, earthquakes triggered by the Kīlauea volcanic eruption and summit collapse badly fractured the surrounding rock. By January 2020, deep new cracks forced park officials to shut the original viewing platform, establishing a safer viewing area further back from the cliff edge. Later that same year, heavy surf from Tropical Storm Darby tore away a substantial chunk of rock from the arch's base.

Storm season took its toll

The final blow came during an exceptionally severe storm season. Fueled by a powerful El Niño pattern, the Pacific has seen a high number of tropical systems this year. Tropical Storm Nolo—which rapidly intensified into a hurricane on 24 September, forcing the park's closure—was the third major storm to hit Hawaii in a matter of weeks. It followed Hurricanes Lala in August and Lowell in early September, which had already left the island's infrastructure damaged and its coastlines heavily eroded.

In a statement, the National Park Service described the loss as "the latest transformation of the park's remote and rugged coastline".

Park officials had long warned that the arch's lifespan was limited. "The sea arch will eventually crumble into the sea," the park service noted in 2021. "However, others will replace it as the cliff slowly migrates inland."