The U.S. National Park Service (NPS) said Hōlei Sea Arch was intact on September 23, but had disappeared by the evening of September 27. The exact time of the collapse is unknown and may have occurred while the park was temporarily closed in response to Typhoon Nolo.
According to NPS, the cliffs on either side of the arch had shown signs of instability years prior due to volcanic activity, earthquakes, and erosion. Therefore, the disappearance of Hōlei Sea Arch was not entirely unexpected for regional managers.
Earthquakes that occurred during the 2018 eruption of Mount Kīlauea, along with subsidence at the summit, damaged the cliffs near the arch. In 2020, new cracks and instability continued to appear, forcing the park to close the original observation point in January.
A safer viewing area, located further from the cliff edge, was opened in March of the same year. Later in 2020, large waves caused by Tropical Storm Darby continued to erode parts of the rock at the bottom of Hōlei Sea Arch.
Hōlei Sea Arch was formed when ocean waves eroded ancient lava flows, creating a natural rock arch jutting out into the Pacific Ocean. The structure is approximately 90 feet (27 meters) tall and has stood for about 550 years.
The collapse of Hōlei Sea Arch occurred amidst an unusually severe hurricane season in Hawaii.
Typhoon Nolo was the third major tropical storm to hit the archipelago in recent months, following Typhoon Lala in August and Typhoon Lowell in early September. The two previous storms caused flooding, damaged roads, toppled trees, and disrupted power lines in many areas.
The collapse of Hōlei Sea Arch also demonstrates how rapidly the Hawaiian coastal landscape can change under the combined effects of volcanoes, earthquakes, ocean waves, and extreme weather.
NPS is now warning tourists to stay away from the area where the rock arch once stood. The coastal cliffs there remain very unstable and could collapse without warning.
After the rock arch disappeared, some tourists still attempted to access the cordoned-off area to observe the remnants of the natural structure. The NPS warned that this action not only threatened the lives of tourists but could also endanger rescue workers.
Hōlei Sea Arch was once considered one of the geological symbols of Hawaii Volcanoes National Park. After about 550 years, this landmark has become part of geological history instead of continuing to be a prominent feature on the Hawaiian coastline.
Source: https://baovanhoa.vn/the-gioi/vom-da-noi-tieng-550-tuoi-o-hawaii-do-xuong-thai-binh-duong-271213.html
