VOLCANO, Hawaii – Visitors to one of the world's most active volcanoes are being kept hundreds of feet away from a 55-acre lava delta that authorities believe may soon collapse into the Pacific Ocean.
Eruption-watchers from the U.S. Geological Survey's Hawaiian Volcano Observatory on Monday reported lava continuing to flow into the ocean off the west side and tip of the expanding black delta, while small breakouts of lava from higher up the slopes of Kilauea Volcano were described as "resembling a string of holiday lights."
Kilauea, star attraction of Hawaii Volcanoes National Park, has been luring thousands of visitors each week to its ongoing eruption since 1983. Some are treated to spectacular displays as molten lava spews into the ocean, but these days most are missing the show, partly because of the long hikes to the best viewpoints and the danger of collapsing lava.
The flow repeatedly builds up and then takes away land from Hawaii's slowly expanding Big Island. Rather than blowing its top, Kilauea's ongoing eruption pushes molten lava through a network of tubes under the thin lava crust.
The thin lava delta is the largest buildup of unstable land extending from Kilauea out into the ocean since the marathon eruption began, according to volcanologists.
Some predict the next giant lava collapse could be bigger than the rapid crumbling of 44 acres over 4 1/2 hours on Nov. 28, 2005. That collapse brought down a section of sea cliff and sent molten rock and boulders rocketing into the air.
But Jim Kauahikaua, head of the observatory, said the bench could continue to crumble away a few acres at a time rather than collapsing all at once.
Because of the danger even on supposedly solid ground, park officials have put up a rope barrier 300 to 600 feet back from the edge of the new lava delta. No one was injured in the 2005 collapse, but a park visitor was killed in 1993 when lava he was standing on cracked away into the ocean.
While up to 900 people a day visit the sprawling park, only a few dozen a day make the three-mile trek out to the edge of the unstable lava bench, said park ranger Rob Eli.
"It's a difficult, long hike" that can take as long as five hours back and forth from the park's lava-blocked Chain of Craters Road, Eli said.
The unstable lava delta is constantly changing as hardened lava piles up on the slope of the volcano that extends to the ocean floor. Offshore information on the terrain is scarce, said Kauahikaua.
Lava hitting the water at 2,200 degrees forms a rough and unstable mass of lava, rock and sand. It doesn't become a relatively smooth, paving-like surface until the lava builds up above the water, according to scientists.
In a big collapse, the unstable buildup under the delta as well as the huge billows of steam set off by lava hitting the cool water pose a danger to anyone along the shore.
Rangers warn visitors to make a plan for their visit and check the latest reports on dangerous areas.
Meanwhile, a worrisome three-year swelling of Kilauea seems to have ended, according to scientists monitoring instruments at the observatory.
Some suggest a powerful Oct. 15 earthquake may have relieved pressure inside the volcano that some speculated could lead to a more violent eruption at some point.
Generally, the steady flow of lava in Kilauea's long-running eruption has caused the volcano to deflate, but the inflation that started in 2003 came with an increased lava flow.