Geologists warn of possible explosive eruptions from Hawaii volcano

Geologists warned Wednesday that Hawaii's Kilauea volcano could erupt explosively and send boulders, rocks and ash into the air around its summit in the coming weeks.

The U.S. Geological Survey (USGS) said the risk will rise if the lava drops below the groundwater level beneath the summit's caldera, the depression that forms after an eruption. An influx of water inside could cause steam-driven explosions. There's also potential for ash, steam and sulphur dioxide emissions.

Kilauea is one of the world's most active volcanoes.

It has destroyed 36 structures, including 26 confirmed homes, since it began releasing lava into fissures that opened in a Big Island residential neighbourhood last week.

In the weeks ahead, the volcano could eject blocks up to two metres in diameter as much as a kilometre away, the USGS said. It may also send pebbles shooting into the air several kilometres away.

Police went door-to-door in Hawaii to roust residents near two new vents emitting dangerous gases in areas where lava has been pouring into streets and backyards for the past week.

Authorities ordered nearly 2,000 residents to leave two communities in the mostly rural district of Puna on Hawaii's Big Island last Thursday. Some ignored the order and stayed to watch over their property.

But on Tuesday, the emergence of the two new vents prompted Hawaii County to issue a cellphone alert ordering stragglers in Lanipuna Gardens to get out immediately. Police followed up with personal visits.

"There were a number of people at their residences," Talmadge Magno, the administrator for Hawaii County Civil Defence, said at a news briefing. There was no sign of holdouts in Lanipuna afterward, he said.

New vents

Edwin Montoya, 76, had planned to stay to care for animals and keep looters away from his family's property in neighbouring Leilani Estates. But he was forced to evacuate after the new fissures emerged, including one just 1.6 kilometres away.

"I'm in my truck right now on my way up the road," he said. "The police came down here and made me."

Both communities are in a forested, remote part of the Big Island on the eastern flank of Kilauea volcano, which has been erupting continuously since 1983.

In recent years the volcano has mostly released lava in hard-to-reach areas inside a national park or along the coastline. But last week, vents popped open and released lava, gas and steam inside residential neighbourhoods.

No indication when eruption might stop

There's no indication when the eruption might stop, or how far the lava might spread.

There were about 1,700 residents in Leilani Estates and a few hundred in Lanipuna Gardens before last week.

Andrew Nisbet evacuated last week and has no idea what has happened since.

"My home is right in the line of the major breakouts so maybe, maybe not." he said Monday during a community meeting.

'I'm not a dumb-dumb'

Authorities urged Scott Wiggers to evacuate, but he refused.

"I'm in the safest part in the subdivision. There's no threat to my house whatsoever," said Wiggers, a tour guide.

Wiggers said he wasn't leaving his home on the outskirts of the evacuation zone because he worried that if he did, he wouldn't be able to get back in. But he's prepared in case the situation takes a turn.

"I am packed. My truck is loaded. I'm not a dumb-dumb. If I see a threat, I'm out of here," he said.

36 structures destroyed

Officials warn that lava could flow downhill and burn areas that are not currently in danger, and toxic volcanic gas could kill people, especially the elderly and those with breathing problems.

Hawaii Gov. David Ige told evacuees he has called the White House and the Federal Emergency Management Agency to tell officials that he believes the state will need help to deal with the volcano on the Big Island.

There are 14 lava-and-gas producing fissures in Leilani Estates, after the two new ones formed Tuesday. But the flow of lava is not constant.