Hawaii volcano could blow within a week, launching boulders the size of fridges miles into the air, experts warn

Hawaii’s authorities have also scrambled to move tens of thousands of gallons of highly flammable chemicals – enough to create an explosion more than a mile wide – from the lava’s path

PUBLISHED : Friday, 11 May, 2018, 4:19am
UPDATED : Friday, 11 May, 2018, 5:31am

Hawaii’s Kilauea volcano could blow its top within a week – and if it does, it could hurl boulders the size of refrigerators miles into the air, shutting down airline traffic and endangering lives in all directions, scientists said Thursday. 

“If it goes up, it will come down,” said Charles Mandeville, volcano hazards coordinator for the US Geological Survey. “You don’t want to be underneath anything that weighs 10 tons when it’s coming out at 120 miles per hour.”

The remarks came as Hawaii authorities scrambled to move tens of thousands of gallons of highly flammable chemicals – enough to create an explosion more than a mile wide – from the lava’s path and the state’s governor warned that mass evacuations might be needed as the volcano’s eruption became more violent.

Geologists have warned that Kilauea may be entering a phase of explosive eruptions, the likes of which Hawaii has not seen in nearly a century, that could hurl “ballistic blocks” and dust towns with volcanic ash and smog. 

“We know the volcano is capable of doing this,” Mandeville said, citing similar explosions at Kilauea in 1924, 1790 and four other times in the last few thousand years. “We know it is a distinct possibility.” 

Hawaii eruption could be about to get much worse, geologists warn

Mandeville would not estimate the likelihood of such an explosion, but said that the internal volcanic conditions are changing in a way that could lead to a blast in about a week. A summit blast could also release steam and sulphur dioxide gas. The volcano’s internal plumbing could still prevent an explosion.

The added threat of an explosive eruption could ground planes at one of the Big Island’s two major airports and pose other dangers. Officials at the national park around the volcano announced that it would close because of the risks. 

The problem, Mandeville said, is that the lava lake at the summit of Kilauea is draining fast – about 6.5 feet (2 metres) per hour. 

The lava levels in the lake are dropping because lava is spewing out of cracks elsewhere in the mountain, lowering the pressure that filled the lava lake. 

In little more than a week, the top of the lake has gone from spilling over the crater to almost 970 feet (295 metres) below the surface as of Thursday morning, he said.

“This is a huge change. This is three [American] football fields going down,” Mandeville said. 

More evacuated in Hawaii as lava and toxic gases hit neighbourhood

The fear is that it will go below the underground water table – another 1,000 feet further down – and that would trigger a chain of events that could lead to a “very violent” steam explosion, Mandeville said. 

At the current rate of change, it is estimated, that is about six or seven days away. 

Once the lava drops, rocks that had been superheated could fall into the lava tube. And once the lava drops below the water table, water hits rocks as hot as almost 2,200 degrees (1,200 degrees Celsius) and flashes into steam. When the water hits the lava, it also steams. And the dropped rocks hold that steam in until it blows. 

A similar 1924 explosion threw pulverised rock, ash and steam as high as 5.4 miles into the sky (9 kilometres) for a couple of weeks. If it happens again, the danger zone could extend about 3 miles (5 kilometres) around the volcano, Mandeville said.

Watch: Hawaii volcano creates 70-metre lava fountain from new fissure

After a new fissure opened on Wednesday a half mile (0.8km) from a geothermal power plant, Hawaii Governor David Ige set up a task force to remove the pentane fluid used in the plant’s turbines. If the chemical ignites, the resulting explosion could create a blast radius of up to 1 mile (1.6km), Ige said.

The Puna Geothermal Venture plant sits at the edge of the Leilani Estates residential area on Hawaii’s Big Island, where lava from 15 volcanic fissures has so far destroyed 36 structures, most of them homes, and forced the evacuation of about 2,000 residents.

A new area just to the west of the residential area was evacuated on Wednesday after toxic clouds of sulphur dioxide started shooting up through cracks in a road, County of Hawaii Civil Defence reported.

“As more fissures open and toxic gas exposure increases, the potential of a larger scale evacuation increases,” Ige wrote in a post on Twitter Wednesday evening.

Hawaii volcano to spew more lava, but scientists don’t know where

“A mass evacuation of the lower Puna District would be beyond current county and state capabilities, and would quickly overwhelm our collective resources,” Ige tweeted, saying in a separate post he had requested federal disaster assistance.

The lower part of the Puna District, of which Leilani Gardens is a part, covers dozens of square miles and is home to many thousands of residents. It has the highest possible hazard rating for lava flows, according to the US Geological Survey.

A large explosion in Kilauea sent up a column of ash on Wednesday that blew to the south-southwest, the USGS said.

Surfers bobbing in the ocean off Kona on the west side of the island complained of volcanic smog, known as vog, that could be seen in a haze over the coast.

“Does that hat protect against vog?” one surfer was heard quipping to another about the floppy sun hat he was wearing.

Hawaii shaken by several earthquakes, biggest 6.9-magnitude, near volcano

In the village of Pahoa, about 24 miles (39km) from Kilauea, school closures have added to a sense of disarray and ramped up stress levels, said gallery owner Amedeo Markoff, 49.

“It’s like our version of a snow day – a lava day,” joked Markoff, as his 10-year-old son Kai sat next to him in their business.

Magma is draining out of the volcano’s sinking lava pool and flowing underground tens of miles eastward before bursting to the surface in and around homes on Kilauea’s eastern flank, just a few miles from Pahoa.