Hawaii Volcano Erupts, Spews Toxic Gas
VOLCANO, Hawaii, March 27, 2008 (ENS) - Explosive eruptions and noxious gas emissions at Kilauea Volcano on the Big Island of Hawaii this week have got scientists working around the clock to understand what will happen next and how to keep the public out of harm's way.

Scientists are monitoring gas emissions and seismic activity at Kilauea, which on March 19 experienced its first explosive eruption since 1924. The volcano is emitting sulfur dioxide at toxic levels.

During the past 24 hours, ash emission has continued from the Kilauea summit but there were no new explosions. Observers overnight reported sporadic and faint incandescence reflected in the base of the ash plume.

View of the ash-rich plume in Halema'uma'u from the southeast side of Kilauea Caldera. Ash floats down-wind of the plume. (Photo courtesy USGS)

Sulfur dioxide emissions at the volcano's summit have increased to a rate that is likely to be hazardous for areas downwind of Halema'uma'u crater. Future explosions from Halema'uma'u Crater are possible, scientists say.

"This historic activity has created new hazards that did not exist before - explosive eruptions as well as toxic sulfur dioxide emissions - in the middle of a national park, said U.S. Geological Survey Volcano Hazards Program Coordinator John Eichelberger.

Most people are sensitive to sulfur dioxide at these levels. Children and individuals with asthma, chronic obstructive pulmonary disease, or other breathing problems especially should avoid downwind areas.

"Our job is to give emergency responders and the civil defense community the very best information we can provide about what the volcano is doing and what it is likely to do in the future," Eichelberger said.

The National Park Service has closed Crater Rim Drive through the south caldera area until further notice. The U.S. Geological Survey is issuing frequent updates, which can be accessed at http://hvo.wr.usgs.gov/kilauea/.

Kilauea is the youngest and southeasternmost volcano on the Island of Hawaii. Topographically Kilauea appears as only a bulge on the southeastern flank of Mauna Loa, and so for many years Kilauea was thought to be a mere satellite of its giant neighbor, not a separate volcano.

But research over the past few decades shows clearly that Kilauea has its own magma system, extending to the surface from more than 40 miles deep into the Earth.

While not erupting explosively for 83 years, a slower eruption of Kilauea volcano began in 1983 and continues at the cinder-and-spatter cone of Pu'u 'O'o. Lava erupting from the cone flows through a tube system down more than six miles to the sea.

Lava entering the ocean poses two additional hazards - potential collapse and laze. Lava entering the ocean builds a delta over its own rubble that is extremely unstable. That delta can collapse without warning and expose very hot surfaces to waves which can explode and throw rock debris up to one-quarter mile inland. For these reason, spectators should avoid the delta and the area one-quarter mile inland.

The interaction between seawater and lava produces a steam plume laced with acids and fine particles of volcanic glass or 'laze' that is unhealthy if inhaled and can produce skin or eye irritation if contacted. Hawaii County continues to open a public viewing area between 2 and 10 pm with the last car allowed in at 8 pm. For details, see www.lavainfo.us.

Copyright Environment News Service (ENS) 2008. All rights reserved.