HOMER - While most people find good reason to take cover before an impending volcanic eruption, scientists from New Mexico Tech, collaborating on volcanic lightning studies with the Geophysical Institute/Alaska Volcano Observatory, were drawn to the explosive area to monitor the little-understood phenomenon that occurs within highly charged ash clouds.
When Mt. Redoubt started rumbling in January, a team of researchers ventured to the volcano site to deploy a series of radio sensors to monitor the lightning activity created within the volcanic plumes. Within a matter of weeks, Redoubt's eruptive activity allowed the array of stations to start returning clear and dramatic information about the electricity created within the resulting lightning.
The National Science Foundation awarded New Mexico Tech a three-year grant to study volcanic lightning in 2007, with the University of Alaska Fairbanks and the Alaska Volcano Observatory as collaborators. According to New Mexico Tech Public Information Officer Thomas Guengerich, the school's volcanic lightning studies aim to advance the understanding of electrical activity during an eruption.
He added that Redoubt's data is likely to help scientists understand fundamental electrical mechanisms within plumes of ash, steam and other hot gases above active volcanoes.
Redoubt erupted explosively close to 20 times in the first seven days of activity. Guengerich noted that scientists observed several different phases of electrical activity in the process.
"When Redoubt volcano erupted, Tech scientists and researchers had their first-ever data from an initial eruption of an explosive volcano," he said.
Lightning Mapping Arrays are set up in several areas of the country for research studies and are becoming increasingly used by meteorologists to help issue severe weather warnings. The portable stations have been deployed at active volcanoes only twice before.
Four Lightning Mapping Array stations were placed along a roughly 60-mile stretch on the east side of Cook Inlet across from the volcano. The northernmost sensor is located in Nikiski, the second at a fire station south of Kenai, the third at the Clam Gulch Lodge, and the southernmost sensor at Ninilchik School.
"With Redoubt, we have data for all the eruptions and will be well posed to examine trends as a function of time," said Steve McNutt, Coordinating Scientist at the Alaska Volcano Observatory. "We are accumulating a fantastic data set of the eruptions."
In addition to the Lightning Mapping Array, AVO is gathering data from 11 local seismic stations, two infrasound arrays and two radar stations. Other data is being recorded by webcam, remote sensing, gas flights, direct observations and sampling.
According to Guengerich, thousands of individual segments of a single lightning strike can be mapped with the Lightning Mapping Array and later analyzed on high-end computers to reveal how lightning initiates and spreads throughout a thunderstorm ... or within a volcanic plume.