A broad, slow flow of lava is moving through thick brush just a few hundred yards away from the county viewing area in Kalapana, setting off fires and small methane explosions.

No structures are in danger, but Civil Defense has had to relocate some of its facilities.

Staff geologists from the U.S. Geological Survey's Hawaiian Volcanoes Observatory have been making daily trips to Kalapana to watch the expanding, slow-moving surface flows, and they also did a helicopter overflight Friday.

"As of this morning, the flow ... was about 250 meters north of the road, and is expected to keep advancing," said volcanologist Janet Babb. "As it continues to slowly advance, we may see some burning vegetation in the kipuka."

For safety and liability reasons, the public is not allowed to walk up to the flow front and is confined to a trail over months-old lava that follows the path of the buried Chain of Craters Road in Kalapana.

Babb said close-up views of the flow may not yet be visible, but distant views of surface activity may be available, especially at night.

"It's kinda close to the viewing area. Where it goes is anybody's guess," said Civil Defense Administrator Quince Mento.

The current flow is pushing along the eastern boundary of the 2007-2010 flow field, in a vegetated region between lava that erupted from the Kupaianaha vent 20 years ago and lava that was molten as of last October. If the supply of lava from the current vent remains constant and uninterrupted, at some point in the next few days the flow will cross the viewing area path on its way to the sea.

The flow is not threatening any people or sbuildings, but several county structures have been moved around in anticipation of its arrival.