For the last decade, a cauldron stewed inside Hawaii Volcanoes National Park.

A giant lake of churning lava, over 500 feet across and hundreds of feet deep, drew visitors from around the planet to the lake's eerie red glow, visible at night as the sun set beyond Hawaii's Big Island. Just in April, the burgeoning lava lake overflowed its banks and spilled onto the floor of the volcano's summit.

But over four months later, the scorching lake is gone. Following an onslaught of volcanic quaking and explosions this summer, it drained, completely.

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"For the past 10 years we’ve been spoiled. You could walk 20 yards and see the largest lava lake on the planet," Ben Hayes, the park's Chief of Interpretation and Education, said in an interview. "Instead, there’s a massive, colossal hole."

The famous national park shuttered in May after violent quakes, falling boulders, and explosions of ash from the crater rendered the area exceedingly dangerous. It's the longest the park has been closed in its 102-year-long history, said Hayes.

Now, on September 22, the park is set to reopen.

The draining lava lake in May 2018.Credit: usgs

The explosions have stopped. But it will be a vastly different place. A land famous for orange molten rock will be dry.

"There's not going to be any lava," Bobby Camara, who spent three decades working as a ranger at Hawaii Volcanoes National Park, and has since retired nearby, said in an interview.

All the noticeable quakes have stopped, too. It's as if Hawaii's youngest volcano, Kilauea, has gone to sleep.

"Nothing. Nothing. There is nothing -- everything stopped," said Camara.

Still, Hayes is expecting some 10,000 visitors on September 22, double the daily average, and continued heavy visitation after that. The steaming, volcanically-ravaged park is an island destination, and for good reason.

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Yet without lava, the park's programming, like its ranger talks and presentations, will have to focus on the recent dramatic alteration of the land. After all, it's not just the lava lake that's gone. The greater Halema‘uma‘u Crater at the volcano's summit -- which once held the lava lake -- has collapsed down by some 1,300 feet.

"It's like you’re looking into the Grand Canyon now," said Hayes.

"The amount of change is unprecedented in the 102 years there's been a national park," he added. "We’ve had 80,000 earthquakes over the last four months."

A return of lava?

The lava isn't just gone from Hawaii Volcanoes National Park. It's also stopped flowing about 24 miles east, where for three months, Fissure 8, the site of Hawaii's newest volcanic cone, intensely gushed lava before cooling off in early August.

A lava river from Fissure 8 flowing to the ocean.Credit: usgs

This could be a simple pause. Or it could be something greater. It could be the end to an immensely active period in Kilauea's life, wherein both the lava lake vanished and the volcano's summit collapsed.

"None of us dreamt that we’d see anything like this in our lives," said Camara, who has seen quite a bit in his day, including Kilauea coming alive with fountaining lava in the early 1980s.

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But what comes next is unknown. 

"It’s too soon to tell whether this is a pause or an end to the recent phase of activity," Ingrid Johanson a research geophysicist at the U.S. Geological Survey's Hawaiian Volcano Observatory, said over email.

The lava lake in 2012 inside Halema‘uma‘u Crater.Credit: usgs

It's hard to say because the goings on inside Kilauea's plumbing system -- the underground labyrinths and channels that carry the lava -- can only be known through indirect means, like measuring how the ground swells, or sinks.

What is known quite well, however, is that for the three dramatic months spanning May through early August, immense amounts of lava flowed from Kilauea's summit area, precisely where the lava lake was once located, to the area around Fissure 8.

As for the halt of flowing lava, one possibility, said Johanson, is that the lava reservoir beneath the park may have lost so much lava, it simply "depressurized," a bit like an air mattress deflating. In this case, there's just not presently enough pressure to force any more lava out.

Early morning incandescent glow from the lava lake in 2009.Credit: usgs

Or, there could be an obstruction, like a collapsed mass of rock, blocking the flow of lava underground.

Either way, Kilauea's summit area in the park has the next hand to play, and Johanson is watching to see what happens next.

Remembering the violence

When the park reopens on September 22, Camara hopes people can appreciate what happened there. The natural violence was extreme.

The Earth rumbled, shook, collapsed, and blew masses of lava and ominous clouds of ash into the sky.

"It was so overwhelming and stupefying that I believe it requires a different level of respect by everyone," Camara said.

Park geologists assess earthquake damage along a trail.Credit: nps

The quaking in the park was so sustained, and ultimately damaging, that much of the park will still remain closed even when some parts reopen.

"In some cases the trails are gone," said Hayes.

Of 150 miles of trail, the park has only been able to safely inspect about 29 miles.

One of the two major park overlooks, outside the Jagger Museum, is off-limits -- to everyone. Structural engineers and geomorphologists (who assess movement of the landscape) found that the hundreds of feet of rock that once stabilized the area had collapsed away, into the crater below.

"That's all gone," said Hayes.

In the end, however, Hayes recognizes that our present experience in Kilauea is fleeting. These changes may be dramatic for the park, and those seeking to glimpse red-hot flowing rock oozing from the Earth, or brewing in a lake.

Quakes wreaked havoc on some park roads.Credit: J. Michael Johnson/NPS

But in the long term, this is normal, expected volcano behavior.

"Hawaii Volcanoes National Park is a wild place and Kilauea is constantly being shaped by uncontrollable natural forces," said Hayes. "This is routine -- and it will continue."

Although much of the park is closed, there's still plenty of volcanically-devastated terrain to see. The main visitor center will be open. You can walk to an overlook of the heavily-altered summit area, or drive through the lava-blanketed land along Chain of Craters Road. Visitors can also get out on the trails not imperiled by falling boulders.

But come night, the dark world of the park is no longer lit aflame by a molten cauldron. The orange-red incandescent brilliance is gone, vanished deep into the Earth, whence it came.

"Now the glow is absent," said Camara. "There’s nothing there."

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