What Did (And Didn't) Cause The Kīlauea Eruption

Apr 23, 2019

Credit USGS

It's been nearly a year since Kīlauea erupted on the Big Island's lower East Rift Zone. The event destroyed more than 700 structures and displaced hundreds, if not thousands, of residents. Scientists are still studying the eruption, but they think they know what did, and didn't, cause it.

According to officials with the U.S. Geological Survey, last year's Kīlauea eruption was unprecedented. It was the largest eruption in 200 years, and caused the biggest collapse of the volcano's summit.

For the better part of a year, the USGS has been sifting through mountains of data recorded during the event. In that time, they've been asked what caused the eruption -- specifically, whether the Puna Geothermal Venture played any role.

"There is no evidence, that we're aware of, that the geothermal drilling or production on the East Rift Zone of Kīlauea had any impact whatsoever on the events of 2018," said Tina Neal, scientist-in-charge at the Hawaiian Volcano Observatory.

"You have to think about the scale of energy, and scale of activity here. The geothermal production is occuring in a very small part of the East Rift Zone. And what we saw leading up to the eruption in 2018 was almost an entire volcano-wide event."

Neal says Kīlauea was showing signs weeks before magma surfaced in Lower Puna. And that the eruption was most likely caused by the build-up of magmatic pressure at the volcano's summit, combined with a weakened rift zone.

According to the USGS, the relationship between magma supply, magmatic pressure, and strength of the volcanic structure are the typical culprits for most eruptions around the world.

The USGS recently downgraded Kīlauea's alert level to "normal." But Neal says the volcano is still very active, and continues to be a threat to nearby areas.