HONOLULU (HawaiiNewsNow) - Scientists studying Kilauea believe the Big Island volcano is surging toward a violent future. Volcanologist Don Swanson collected samples of ash and rock dating back 2,500 years. They show a pattern.
"Kilauea has had long periods of explosive activity in the past, much longer than we had previously realized," he said. "Some of those explosions during those periods can be very deadly."
Even more deadly than the explosion at Mount St. Helens in 1980 that killed 57 and destroyed 150 square miles of forest.
An explosive eruption at Kilauea in 1924 killed one person. But in 1790, another killed 200.
"We know that it's the most lethal volcano in the U.S.," University of Hawaii Geology professor Michael Garcia said.
U.H. researchers studied Kilauea samples from the edges of Halemaumau crater and performed chemical analyses on them. The U.S. Geological Survey conducted carbon dating that yielded a startling discovery - Kilauea has gone through phases of explosive eruptions that occurred intermittently over years or decades.
"The total interval in which Kilauea is dominantly exploding rather than producing lava flows is much greater, 60 percent of its history over the last 2,500 years," Garcia said.
There were also long periods of no eruptions because less magma was supplied to the volcano.
Swanson predicts another violent phase is coming when Kilauea will explode and send out surges.
"A surge is a horizontally moving mixture of hot gas and ash. It moves at hurricane velocity. You can't escape it," he said.
Garcia helped gather and study the Kilauea samples. He agrees with Swanson's theory. But neither scientist can pinpoint when the next explosive phase will begin.
"Right now we're in a phase when we're producing lava flows," Garcia said. "But how long will that last? Will that last another decade? Will that last another century?"
"The floor of Kilauea's caldera will probably have to sink substantially. That will be the warning signal," Swanson said. "But before that happens there's absolutely no reason to stay away and to fear Kilauea. It's just a wonderful place to come to."
It is for now. But if science is correct, that will change.