National Park Service crews are planning to make helicopter water drops today to try to extinguish smoldering vegetation ignited by a brief lava flow last week in the upper East Rift Zone of Kilauea.

Joe Molhoek, fire management officer for the National Park Service in the Pacific Islands, said about 7 acres were burned or scorched by the brief outbreak of lava late June 18 or early June 19. In addition, about 20 acres has turned brown and died off from the poisonous fumes and steam released last week from new cracks that opened in the upper East Rift.

The lava flow near Kane Nui o Hamo is in a rare, protected rainforest, and if the smoldering layers trigger a wildfire it could consume more of the 2,500-acre East Rift Rainforest Special Ecological Area. That area is home to threatened and endangered species, and has been protected from invasive, non-native plants and animals.

"If we had a significant period of drying, I think it can start to spread," Molhoek said. "There's really not a whole lot of spread right now, but as those fumes are killing the vegetation around it, obviously it becomes more flammable, and if we get into a drying trend, we don't want the fire to spread into the rainforest any more.

"There's a pretty significant resource there of endangered species."

Members of a 10-person fire support crew from Whiskeytown National Recreation Area near Redding, Calif., hiked out to the lava outbreak yesterday and reported about three fingers of smoldering fire in layers of decomposed ground vegetation, or duff.

Kilauea remained quiet yesterday after magma last week forced its way into the upper East Rift Zone of Kilauea, accompanied by hundreds of earthquakes. The magma movement caused the East Rift to expand and open new cracks, and broke to the surface at Kane Nui o Hamo before stalling.

The earthquakes seemed to block or divert the flow of magma that had been flowing into the Pu'u 'O'o area and from there down to the sea, which in recent years has been the focus of the Kilauea eruption. Since then, the lava flows to the ocean have stopped, and Pu'u 'O'o has collapsed.

Scientists say they aren't sure what to expect next from the eruption, which began in 1983.

The national park's eastern boundary in the Puna district near Kalapana remains closed today, along with Chain of Craters Road and Hilina Pali Road. Parks officials are evaluating the risk today to determine whether Chain of Craters can be reopened soon.

In the meantime, much of the park remains open, including most of Crater Rim Drive, the Kilauea Visitor Center, Jaggar Museum, Thurston Lava Tube, Volcano House Hotel, Kilauea Military Camp and Volcano Art Center Gallery.

Reach Kevin Dayton at kdayton@honoluluadvertiser.com.