A giant sea arch that was a major landmark on Hawaii’s rugged coastline has collapsed into the Pacific Ocean more than 500 years after it was naturally formed, the local parks department has confirmed.
Hawley Sea Arch stands approximately 90 feet (27 meters) high in Hawaii Volcanoes National Park on the south coast of the Big Island, the largest and youngest of the Hawaiian archipelago.
The arch was formed about 550 years ago, when an ancient lava flow from the eruption of one of the island’s six volcanoes crashed into the edge of a cliff and carved an arch, creating a natural wonder that has drawn visitors to the site for years, according to the National Park Service (NPS).
The exact time of the collapse is unknown, but the Volcanoes National Park team announced on social media Thursday that the arch was still standing on Wednesday, September 23, when the park was temporarily closed due to Tropical Storm Noro.
When it reopened on Monday, September 28th, the arch was gone.
“Yes, it’s true. Rest in peace, Arch of the Holy Sea,” Volcanoes National Park said in a Facebook and Instagram post, along with before and after photos revealing the dramatic change in scenery.
“The Hawley Sea Arch was a very special place for many of our visitors,” he added.
But the dramatic changes to the rugged and remote coastline have long been expected, according to the NPS.
“This formation is beautiful but ephemeral and has a limited lifespan,” the NPS said in a description of this beautiful site on its website.
“The sea arch will eventually collapse into the sea, but other arches will replace it as the cliff slowly moves inland,” it added.
According to the NPS, the cliff’s longevity is determined by differential erosion, a process in which softer rock wears harder and faster than stronger, more durable rock.
The landscape is regularly reshaped by differential erosion, which explains how this arch was formed more than five centuries ago.
Park officials knew that the waves constantly crashing on the sea arch would eventually collapse into the Pacific Ocean, but they could not predict exactly when that would happen.
Volcanoes National Park urged visitors to keep their distance from the unstable cliff edges to avoid endangering themselves and first responders.
