Lava Chemistry Creating Volcano Mystery
From Daily Herald news services
VOLCANO, Hawaii (AP) -- Scientists have found possible differences in lava samples at Kilauea volcano's summit and its vent 20 miles away, causing them to question the volcano's underground workings.
The long-standing view has been that the lava is rising from a magma reservoir under the summit and moving through the east rift zone to the Puu Oo vent, said Michael Garcia, a University of Hawaii-Manoa geologist-geophysicist.
But lava samples collected from Puu Oo appear to be different from those taken during the three major explosions at the summit on March 23, April 9 and April 14, he said.
That evidence indicates the volcano's plumbing is more complicated than originally thought.
"If there's a difference, it means some other processes are going on," Garcia said.
This year's summit eruption was the first opportunity in 26 years to look at how magma moves to the volcano, he said. The last eruption there was in September 1982.
"We're waiting for another opportunity to sample it," he said. "It's not like crawling under a house to look at the plumbing. We have to use the lava to test chemistry as a tool to learn how lava moves to the mantle through the volcano and gets to the surface."
He cautioned that his lab is still investigating to determine whether the lava samples may be contaminated.
Scientists need to work on understanding whether there's a magma path for Puu Oo that's distinct from the one delivering lava to the summit caldera, said Paul Okubo, a Hawaiian Volcano Observatory geophysicist-seismologist.
"It is an extremely complex system, and we kind of depend on activity and being able to track the activity to try to understand what some of the complexity is," Okubo said.
Researchers in Garcia's lab are testing a collection of lava samples taken from many eruptions over the years at the summit and at rift zones.
"The question is, how do they compare?" he said. "Are they similar or different? We're trying to test how magma moves to the volcano."
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Information from: Honolulu Star-Bulletin, http://www.starbulletin.com
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