Collapse of Holei Sea Arch in Hawaii Volcanoes National Park due to erosion and storms

Consensus Summary

The Holei Sea Arch, a centuries-old natural landmark in Hawaii Volcanoes National Park, collapsed into the Pacific Ocean between Wednesday 23 September and Sunday night, on 27 September. Both 7NEWS and The Guardian confirm the arch, which stood at more than 27m (around 90ft) high, was formed about 550 years ago through ocean erosion. The collapse followed Tropical Storm Nolo, which forced the park to temporarily close, and was not unexpected given the arch’s long-term instability. The National Park Service (NPS) had warned visitors to stay away due to falling hazards, with social media showing people ignoring warnings and entering the dangerous area.

The arch’s formation dates back to ancient lava flows, with the US Geological Survey noting in 2014 that erosion would eventually claim it. The Guardian details how earthquakes during the 2018 Kīlauea volcanic eruption and subsequent tropical storms, including Tropical Storm Darby in later that year, weakened the cliffs. The NPS had already closed the original viewing area in January 2020 after new cracks appeared, reopening a safer site three months later. Both outlets agree the collapse was inevitable, but The Guardian emphasizes the role of recent severe storms in accelerating its demise.

The NPS described the collapse as part of the park’s natural transformations, with 7NEWS quoting officials warning of ongoing risks. The Guardian provides additional context, noting that Nolo intensified into a hurricane on 24 September and was the third major storm to hit Hawaii in recent months, following Hurricanes Lala in August and Lowell in early September. Experts cited the influence of a 'supercharged' El Niño, which has intensified storm activity in the Pacific. While 7NEWS focuses on the immediate danger to visitors, The Guardian links the collapse to broader climate patterns and the park’s history of volcanic and storm-related instability.

The two sources differ slightly on the arch’s height, with 7NEWS stating it was 'more than 27m' and The Guardian reporting 'around 90ft' (approximately 27.43m). The Guardian also provides a more precise timeline, confirming the arch was still standing on Wednesday 23 September, whereas 7NEWS only specifies a broader window. These discrepancies are minor but highlight how different outlets emphasize varying details. Both agree, however, that the collapse was a result of natural processes exacerbated by recent extreme weather events.

The aftermath of the collapse has left the area unstable, with the NPS urging caution. The Guardian suggests the arch’s disappearance is part of a larger pattern of coastal erosion and storm damage in Hawaii, while 7NEWS focuses on the immediate risks to tourists. Neither article speculates on future events, but both imply that further changes to the coastline are likely. The NPS’s warnings and the public’s disregard for safety remain key concerns, as the park continues to evolve due to both natural forces and human activity.