Kilauea gives experts new science clues
HONOLULU: Hawaii’s Kilauea volcano may be disrupting life in paradise with its bursts of ash and bright-orange lava, but it also has scientists wide-eyed, eager to advance what’s known about volcanoes.
The good news is: Volcanoes reveal secrets when they’re rumbling, which means Kilauea is producing a bonanza of information.
While scientists monitored Big Island lava flows in 1955 and 1960, equipment then was far less sophisticated. Given new technology, they can now gather and study an unprecedented volume of data.
“Geophysical monitoring techniques that have come online in the last 20 years have now been deployed at Kilauea,’’ said George Bergantz, professor of earth and space sciences at the University of Washington. “We have this remarkable opportunity ... to see many more scales of behaviour both preceding and during this current volcanic crisis.’’
Starting on May 3, Kilauea has fountained lava and flung ash and rocks from its summit, destroying hundreds of homes, closing key highways and prompting health warnings. Kilauea is one of five volcanos that form the Big Island, and is a “shield” volcano _ built up over time as lava flows layer on top of layer.
Technically speaking, it has been continuously erupting since 1983. But the recent combination of earthquakes shaking the ground, steam-driven explosions at the top, and lava creeping into a new area some 20 kilometers from the summit represents a departure from its behaviour over the past 35 years, said Erik Klemetti, a volcanologist at Ohio’s Denison University.
What’s happening now is a bit more like the Kilauea of nearly a century ago. In 1924, steam explosions at the summit lasted for more than two weeks. Scientists are looking into what caused the change and whether this shift in the volcano’s magma plumbing system will become the new normal.
Radar allows researchers to measure the height of ash plumes shooting from the summit, even when they occur at night. Plume heights are an effect of how much heat energy is released and the explosion’s intensity.
“It’s one of the key factors that dictates how far ash will be dispersed,’’ said Charles Mandeville, volcano hazards coordinator for the US Geological Survey. The other is where the winds are blowing. Such knowledge is useful in alerting the public.
Scientists can also monitor where gas is emerging, as well as determine its composition and volume. They can even measure the subtle rise and fall of the ground over a broad area and time — down to seconds — which suggests when and where magma
is pooling underground.
Discovering variations or correlations between past and present activity provides more clues on what’s happening. It also helps scientists understand past lava flows, anticipate what could occur next, and pinpoint signs or patterns before an eruption.
“You’re sort of zeroing in on finer and finer levels of detail into how the volcano works,’’ said Michael Poland, a US Geological Survey volcanologist. “The more stuff you put on the volcano to make measurements, the more you realise there’s stuff going on that you never knew.”