Lava from Hawaii volcano flowing towards geothermal plant

A broad lava flow is cascading towards a Hawaii geothermal power station, posing a new hazard as molten rock from the erupting Kilauea volcano bulldozes relentlessly through homes and yards.

On Saturday the lava was less than a kilometre from the Puna Geothermal Venture (PGV), according to the US Geological Survey, having destroyed dozens of nearby houses in the past few days.

Since Hawaii's Kilauea volcano began a once-in-a-century-scale eruption on May 3, authorities have shutdown the plant, removed 227,000 litres of flammable liquid and deactivated wells that tap into steam and gas deep in the Earth's core.

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

"The flow from fissures 21 and 7 was widening and advancing," Janet Snyder, a spokeswoman for the County of Hawaii, said in an email on the position of lava heading northeast towards PGV.

Hawaii Governor David Ige has said the wells are stable. But lava has never engulfed a geothermal plant anywhere in the world 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.

In just the past 24 hours there were between 250 and 270 earthquakes at Kilauea's summit, with four explosions on Saturday sending ash as high as 4.5km in the air, said Stovall and National Weather Service meteorologist John Bravender.

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, Bravender said.

US Marine Corp and National Guard helicopters are on standby for an air evacuation in the event fissure activity cuts off Highway 130, the last exit route for up to 1,000 coastal residents. Cracks in the highway have yet to emit hydrogen sulfide gas which would indicate magma was rising towards the surface, Stovall said.

Reuters