HILO, Hawai'i — Scientists at Kilauea Volcano are pondering the big question: Where is 250,000 cubic yards of magma going if it's not flowing each day to the Pu'u 'O'o eruption?

The answer likely will determine whether the eruption at Kilauea Volcano pauses, resumes at Pu'u 'O'o or migrates to some other part of the volcano to put on a whole new show.

Magma that forced its way into the upper East Rift Zone of Kilauea and caused hundreds of earthquakes finally cracked the surface late Monday or early yesterday morning, briefly creating a new area of eruption. Scientists dubbed the new outbreak Episode 56, part of the ongoing eruption that began in 1983.

National Park Service staff closed a portion of Crater Rim Drive late yesterday afternoon as a precaution after air-quality testing showed sulphur dioxide emissions from the volcano were "off the chart," said Park Ranger Mardie Lane. It was the second time this week parts of the road were closed because of potential volcanic hazards.

Scientists measured concentrations greater than 10 parts per million in a broad area adjacent to Halema'uma'u crater.

When sulfur dioxide concentrations greater than 1 ppm (equal to 1,000 parts per billion) are measured at the Jaggar museum or at the Kilauea Visitor's Center, the buildings are closed and employees and visitors are advised to relocate to areas with cleaner air. It was unclear from the 7 p.m. announcement by scientists whether the sulfur dioxide presence might close the museum or visitor's center today.

The park service also closed the eastern or Kalapana-side boundary of the park, and the state Department of Land and Natural Resources closed the state "Captains Trail" to Pu'u 'O'o.

The Pu'u 'O'o and East Rift areas also remained closed, but that did not stop some visitors. Park Superintendent Cindy Orlando saw three people standing on the rim of Pu'u 'O'o during a surveillance flight Monday.

Parks officials don't know who those people were at the crater, but "our concern goes out to them, and we wonder, do they not know?" Lane said. "It is death-defying to attempt to climb Pu'u 'O'o, be in it, or be near it right now.

"Pu'u 'O'o is so unstable, Pu'u 'O'o remains closed, it always has been closed, we've taken the advice of the scientists who said Pu'u 'O'o is unstable. It's steaming, it's hot, it's gassy, it's collapsing in upon itself, and during these seismic swarms that began Sunday, even more so, the collapses have been significant."

EPISODE SHORT-LIVED

The small outbreak of lava in the East Rift oozed from a fissure about 200 yards long in the pristine forest northeast of Kane Nui o Hamo, less than four miles west of Pu'u 'O'o and eight miles southeast of the Kilauea summit.

But the episode was small and short-lived, and at its farthest point the lava made it only 150 feet from the crack where it leaked to the surface, said Steve Brantley, deputy scientist-in-charge at the Hawaiian Volcano Observatory.

The lava that escaped to the surface was moving sluggishly at 6:45 a.m. but had stopped by the time a team of scientists left the area at 11 a.m. yesterday.

Scientists also reported large volumes of steam issuing from a spot high on the north flank of Kane Nui o Hamo, but the smoke and steam from the crack that released the lava also dropped off significantly during the morning, scientists said.

Experts believe the magma that ordinarily flows into the Pu'u 'O'o area and from there down to the sea as part of the ongoing eruption has been blocked or diverted since early Sunday morning and is now flowing into the upper East Rift Zone.

If the lava flow resumes at Kane Nui o Hamo, it could threaten "spectacular" rain forests, including the 2,500-acre East Rift Rainforest Special Ecological Area, a forest protected from invasive, non-native plants and animals, according to Rhonda Loh, park chief of Natural Resources Management.

MIXED SIGNALS

Despite the discovery of the East Rift surface breakout yesterday, Kilauea sent mixed signals throughout the day.

The eruption at Pu'u 'O'o had tapered off by yesterday morning to a small stream dribbling into the ocean at Poupou, and tests of gas emissions confirmed the activity level at the crater had dropped off significantly.

That and the collapsing floor at Pu'u 'O'o crater confirmed the magma that feeds the crater eruption had been diverted.

The expansion of the upper East Rift Zone continued, evidence that magma continues to flow into the area, widening the rift area by 39 inches. But the rate of the underground expansion slowed yesterday, which suggests magma is not entering the East Rift as rapidly as it was the day before.

The Kilauea summit had been deflating since the swarm of earthquakes began early Sunday, and the deflation was a sign magma was likely leaving the summit area and flowing into the upper East Rift area.

Yesterday, that trend reversed, and the summit began to slowly inflate again. At the same time, seismic tremors that are a sign magma is moving underground dropped off from the peak levels of Sunday and Monday.

"It certainly doesn't look like another slug of magma is moving into the rift zone," Brantley said. "If we were to start seeing another slug of magma start moving out there, the chances for another outbreak would be greater."

On the other hand, the magma that has already made it into the East Rift Zone "is very near the surface, it already reached the surface, so there is a batch of magma there that could start heading toward the surface" and out in a new eruption location.

Brantley wasn't making predictions about what will happen underground, but "if it follows some of the earlier patterns, then at some point it will head down toward Pu'u 'O'o and then supply the vent there."

"Kilauea accommodates magma in very different ways in different time sequences," he said, "so it will be very interesting to see what happens in the next 12 hours."

Reach Kevin Dayton at kdayton@honoluluadvertiser.com.