Volcano music may help detect eruptions

A volcano in Ecuador with a deep cylindrical crater may be the largest musical instrument on Earth, producing unique sounds that could help scientists monitor eruptions, finds a study.

The volcano's crater changed shape after a sequence of eruptions in 2015. The deep narrow crater forced air to reverberate against the crater walls when the volcano rumbled.

"It's the largest organ pipe you've ever come across," said Jeff Johnson, a volcanologist at Boise State University in Idaho.

The new findings show the geometry of a volcano's crater that has a major impact on the sounds a volcano can ever produce.

Johnson added, "Once you realize how a volcano sounds if there are changes to that sound, that leads us to think there are changes going on in the crater, and that causes us to pay attention."

He further said the ongoing eruption of Kilauea in Hawaii could be a proving ground for studying how changes to a crater's shape influence the sounds it makes.

The lava lake at Kilauea's summit drained as the magma supplying it flowed downward, which should change the tones of the infrasounds emitted by the crater.

According to David Fee, a volcanologist at the University of Alaska Fairbanks who was not connected to the new study, listening to Kilauea's infrasound could help scientists monitor the magma depth from afar and forecast its potential eruptive hazards.

When magma levels at Kilauea's summit drop, the magma can heat groundwater, causing explosive eruptions, which is believed to have happened at Kilauea over the past several weeks. This can change the infrasound emitted by the volcano.

The study has been published in Geophysical Research Letters.