Hawaii’s Hōlei Sea Arch, a heavily photographed lava rock formation in Hawaiʻi Volcanoes National Park, has collapsed into the Pacific Ocean, BBC reported. It stood 90 feet (27.4m) tall at the end of Chain of Craters Road on the Big Island.
It formed about 550 years ago.
The National Park Service said the arch was still standing on September 23 and was gone by September 27. The exact time of the collapse is unknown. Tropical Storm Nolo forced the park to close temporarily, and the arch is believed to have fallen then.
The US Department of the Interior confirmed the loss in an October 2 post on X.
How the arch formed
Waves carved the arch from an ancient lava flow through differential erosion. Softer rock wore away faster than harder rock. The sea also worked into cracks in the flow.
The arch took its name from the hōlei, a small endemic plant in the milkweed family, according to Popular Science.
Years of warning signs
The park service said the coastline around the arch had shown signs of instability for years. Earthquakes during the 2018 Kīlauea eruption and summit collapse damaged the cliffs nearby.
New cracks in January 2020 led the park to close the original viewing area. A replacement opened a few months later at a safer distance. Later that year, waves from a tropical storm broke a chunk of rock off the base of the arch.
In 2021, the park service warned that the arch would eventually crumble. Other arches would form, it added, as the cliff slowly migrates inland. The US Geological Survey had cautioned more than a decade ago that the ocean was wearing the arch down daily.
Popular Science reported that Nolo reached Category 3 strength in September. It did not hit the islands directly at that strength. Still, it dropped more than a foot of rain on parts of the Big Island. The outlet said the storm may have contributed to the collapse.
Visitors share photos and memories
Hawaiʻi Volcanoes National Park posted on Facebook that the arch was a special place for many visitors. It asked people to share their favorite Hōlei photos in the comments.
Thousands of people have liked and commented on the park service’s post, BBC reported. Many shared memories of visiting. Others posted their own pictures of the arch.
One Facebook commenter wrote that nothing lasts forever and urged people to appreciate beauty while it is here.
The news also spread on X, where accounts repeated the park service’s September 23 and September 27 dates. The Interior Department’s post carried before-and-after images of the coastline. One showed waves hitting the cliffs.
The other showed the same stretch with no arch.