Kilauea volcano lava covers potentially explosive wells

A lava flow from Hawaii'serupting Kilauea volcano that damaged a geothermal power stationhas stalled, as have lava fountains that had gushed 30 metresinto the air, offering momentary relief to an area under siegefor 25 days, officials said on Monday.

Even so, new blasts from the crater at the volcano's peak sent ash plumesbillowing as high as 4,000 metersinto the sky,and a new fissure was pumping out lava at a rate of onemetreper second, geologists said.

The new fissure sent more lava into the to evacuated LeilaniEstates district in the eastern corner of Hawaii's Big Island.

Lava engulfed the heads of two potentially explosive wells that tap into steam andgas deep in the Earth's core at the 38-megawatt Puna GeothermalVenture on Saturday.

The Hawaii Civil Defence Agency said earlier the wells are "stable and secure," but the plant's operator,Israeli-controlled OrmatTechnologies Inc, said it had not been able to assessthe damage.

Lava has never engulfed any of the world's geothermal plants and the potential threat is untested, according to the head of the state's emergency management agency. Local residents fear an explosive emission of deadly hydrogen sulfide and other gases should wells be ruptured.

Since the volcano began a once-in-a-century-scale eruption on May 3, authorities have shut down the plant, removed over 225,000 litres of flammable liquid, and deactivated the wells.

Magma has drained from Kilauea's summit lava lake and flowed around 40 kilometres east underground, bursting out of about two dozen giant cracks or fissures near the plant.

The38-megawatt plant typically provides around 25 per cent of electricity on the Big Island, according to local power utility Hawaii Electric Light.

Over the weekend, there were more than 250 earthquakes at Kilauea's summit, with four explosions on Saturday sending ash as high as 4,500metres, officials said.

Winds are set to shift on Monday and Tuesday, causing higher concentrations of ash and volcanic smog that will spread west and northwest to affect more populated areas, said National Weather Service meteorologist John Bravender.

U.S. Marine Corps and National Guard helicopters are on standby for an air evacuation if fissure activity cuts off Highway 130, the last exit route for up to 1,000 coastal residents.

More residents in some sections of the Leilani Estates neighbourhood were ordered to immediately evacuate shortly before 8 p.m. local time on Sunday"due to a fast moving lava flow from Fissure 7," a statement from the civil defence agency said.

Officials had no information on how many residents still remained in the neighbourhood or how many people might have already left. Local media has reported that about 2,000 people have already evacuated since the new eruptions began.