Accumulations of cooled, hardened lava created a thick, 30-foot (9.14-metre) high wall of solid volcanic rock channelling fresh lava streams from fissures to the south, away from the PGV plant, USGS scientists said.
Clinton was hit by a flaming ball of literal lava from Hawaii's Kilauea (of Golfers Not Caring fame) Saturday and lived to tell the tale to Anderson Cooper - in surprisingly pedestrian fashion. The gas flows through the ground and up through existing cracks.
Geological Survey scientist Wendy Stovall says the methane can cause explosions when it's ignited while trapped underground. It has since opened more than 20 vents releasing lava, sulfur dioxide and steam.
As those of us across the country look at images of the flowing lava and the hazardous laze, it's easy to forget the Big Island is - well, a big island, about 4,000 square miles.
Volcanologist Mike Burton, at Manchester University, has warned about the dangers of gas that could be emitted now the lava has reached the Pacific Ocean.
Puna Geothermal, owned by Nevada's Ormat Technologies, was shut down shortly after Kilauea began spewing lava on May 3.
Hawaii County has ordered about 2,000 people to evacuate from Leilani Estates and surrounding neighborhoods since the eruption began on May 3.
Almost 50 structures have been destroyed by lava, including dozens of homes.
The plant harnesses heat and steam from the earth's core to spin turbines to generate power, providing for about 25 percent of the island's daily energy demand.
A man named Darryl Clinton was left seriously injured after being hit by a lava bomb while he was sitting in his porch at the weekend, according to Hawaii County Civil Defence Administrator Talmadge Magno.
A flammable gas called pentane is used as part of the process, though officials earlier this month removed 190,000 litres of the gas from the plant to reduce the chance of explosions.
Tourism officials cheered news that a Norwegian Cruise Lines ship that tours the Hawaiian Islands would resume stopping in Kailua-Kona next week.
The observatory said its camera points towards Hilo but the town is mostly shrouded in clouds.