Friday, July 06, 2007

Another volcano eruption in Hawaii

With lava once again flowing across the collapsed floor of the Pu'u O'o crater, the Kilauea volcano eruption that began in 1983 may once again present a spectacle for visitors to Hawai'i Volcanoes National Park.

The return of lava to the bottom of the crater was first reported by tour helicopter operators yesterday morning, and was confirmed by Hawaiian Volcano Observatory scientists yesterday afternoon.

The lava flowed eastward and ponded near the crater center, and loud gas-jetting noises could be heard as lava splattered on the crater floor, scientists said.

While the activity did not prompt any changes in operations at the national park, it hints that lava may once again be flowing from the crater into the ocean. That could take awhile, however, since the floor of the crater collapsed by at least 330 feet during the eruption pause.

"It's nice to see the lava returning to its long-term source," Park Ranger Mardie Lane said. While most of the park is open, the East Rift zone and the trails serving that area remain closed, Lane said.

Lava was last seen at the Poupou ocean entry on June 20, but the supply of magma to Pu'u O'o apparently was temporarily cut off during a swarm of earthquakes that began June 17.

Magma then was diverted into the upper East Rift area, causing the rift zone to expand by nearly 3 feet. A small eruption on June 19 from the upper East Rift covered almost 2 acres with lava, but quickly stalled.

Scientists said the interruption in the flow from Pu'u O'o resembles a similar series of events in late January 1997, when magma stopped flowing into the crater, but resumed after a 23-day pause. Lava resumed its flow toward the ocean a few weeks later.

The eruption from Pu'u O'o has been nearly continuous from 1992 to 2007, and the recent pause was the first stall in the eruption since Dec. 15, 2000.

The current Pu'u O'o-Kupaianaha eruption of Kilauea is the most voluminous outpouring of lava on the volcano's East Rift zone in the past 500 years. The eruption has added nearly 500 acres to Kilauea's southern shore, destroyed 189 homes and other structures, and buried long stretches of highway.


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