Explosive eruption occurs at Hawaii’s Kilauea volcano

An explosive eruption occurred at Hawaii’s Kilauea volcano Thursday, officials said, and authorities warned that an ash plume is expected to cover the surrounding area.

The ash plume rose as high as 30,000 feet and is drifting to northeast over the Big Island of Hawaii, and could reach its largest populated area in Hilo, about 25 miles northeast of the volcano summit, Hawaii County officials and the U.S. Geological Survey said. “You should shelter in place if you are in the path of the ash plume,” county officials said.

Ash is primarily a nuisance and can irritate the eyes, cause breathing problems, reduce visibility, make roadways slippery, and interfere with electrical lines. Fine ash particles are generally a millimeter or less in size.

The explosive eruption occurred at 4:17 a.m. Hawaiian time (7:17 a.m. PDT), and forced the closure of half a dozen schools due to elevated levels of sulfur dioxide, a toxic gas, Hawaii County officials announced.

The area southeast of Kilauea volcano’s summit is in a rural, remote part of Hawaii Island on its eastern edge, far from any major resort areas. The closest resorts, in Kona and the Kohala Coast, are more than 100 miles away on the west side of the island.

The USGS posted webcam footage of an ash plume billowing from Kilauea’s summit, and a plume of ash from an observation tower.

USGS officials last week said they did not expect evac- uations or significant damage from explosive eruptions at Kilauea’s summit because it is so far away from populated areas. Leilani Estates, the small neighborhood that has been affected by lava flows this month that have destroyed homes and other structures, is 25 miles east of the volcano’s highest point.

Explosions that do occur at the summit pose a risk of bombardment by material that could weigh as much as 10 or 12 tons — but only within an area of a half-mile. There are no inhabited areas within half-mile of Kilauea’s summit; the primary risk would be to visitors entering the area, which is home to Hawaii Volcanoes National Park. The National Park Service has ordered most of the park closed.

Locations within several miles of the summit could be subject to falls of marblesized rocks, fine-grained material and ash.

USGS officials said last week they expected the possibility of steam-driven explosions at Kilauea. The recent instability at Kilauea has involved the movement of molten rock to the east of the volcano’s summit, toward Leilani Estates.

Scientists have observed the lava lake at the volcano’s summit drop.

That raises the risk for an explosion at the summit. Normally, when the lava lake level is high, temperatures are so hot that the groundwater in surrounding rocks is kept away from the magma. But as the lava lake levels fall below the groundwater table, water can start interacting with the magma, heating up and creating steam, USGS scientist Donald Swanson said last week.