In news that we hope will inspire many future death metal albums, scientists are reporting that they’ve recorded “volcanic thunder” for the very first time.
The literally epic-sounding phenomenon was recorded near Bogoslof volcano, a remote volcano in Alaska’s Aleutian islands that erupted dozens of times from December 2016 through the summer of 2017. During this spate of activity, which produced tall ash clouds that prompted aviation alerts, researchers set a microphone array on an island some 60 km (37 miles) away.
After analyzing the recordings alongside data from lightning sensors, the researchers were able to pinpoint two distinct instances of volcanic thunder—one on March 8, and another on June 10 2017—associated with lightning within the volcano’s ash clouds. According to a press release issued by the American Geophysical Union, it’s the first time scientists have been able to tease thunderous rumblings out from the general racket caused by the ejection of gases and lava during an eruption.
Have a listen for yourself. This file contains 20 minutes of audio data collected during the March 8 eruption. The clicks that can be heard against a background of lower-pitched whirring (the eruption) are volcanic thunder:
“This was the real challenge for our study: how to untangle the sounds of volcanic thunder from the normal explosive sounds that accompany all volcanic eruptions,” Matt Haney, a scientist with the U.S. Geologic Survey’s Alaska Volcano Observatory and lead author of the study accepted for publication in Geophysical Research Letters, told Earther in an email.
Why should we care about disentangling volcanic thunder? For one, it’s not every day scientists confirm the existence of a suspected geologic phenomenon, especially one with a name that sounds straight out of Ragnarok.
But for Haney, volcanic thunder is really exciting because it offers a potential new way to study volcanic lighting produced in ash plumes. This in turn might tell us something about the size (and hazard level) of the ash plume itself, according to the AGU release.
“It also clarifies what the volcanic thunder signal looks like so it won’t be confused with normal explosive signals during future eruptions,” he said.
Jess Phoenix, a volcanologist and California Congressional candidate not involved with the new study, told Earther the research “presents an exciting avenue for continued learning about volcanoes and eruption processes.”
“Using all available sensory detection and innovation in our monitoring techniques will allow scientists to better understand and identify volcanic hazards and threats,” Phoenix continued in an email. “Infrasound and sonic recordings of volcanoes are an emerging field of study and this article is a great indication that our understanding of volcanoes is evolving.”
Janine Krippner, a volcanologist at Concord University who also wasn’t involved with the new research, told Earther she found it “incredible” that the researchers had figured out how to tease volcanic thunder out of all the other sounds taking place in an eruption. She agreed it could have important implications as far as monitoring volcanic lighting and ash plumes goes.
“To have the volcanic thunder, which not only sounds amazing, it’ll actually help complement the volcanic lightning....that’s really exciting,” she said.