Listen to seismic volcano activity in Iceland – 11/17/2023 – Science

The imminent eruption of the Fagradalsfjall volcano, on the Reykjanes Peninsula, in Iceland, has attracted worldwide attention and now the seismic activity that precedes it can now be followed by audio.

Researchers at Northwestern University, in the United States, developed the Earthtunes application, which transforms seismic frequencies into audible tones.

According to a statement from the university this Thursday (16), while a classic seismograph records movements on the Earth’s surface as wavy lines drawn on a page, Earthtunes allows users to hear, rather than see, this activity.

So far, the recent and ongoing seismic activity in Iceland has sounded like a kind of raucous symphony of slamming doors, hail crashing against a tin roof or window, and people breaking trays of ice cubes.

Seismic activity has become increasingly frequent and intense since mid-October. The report from Sheet he was in Iceland between the 17th and 30th of October and, from the 25th, he began to receive daily alerts from the Icelandic meteorological service of tremors around the Fagradalsfjall area.

But, until then, they were not being linked to an imminent volcanic eruption. As the area is located between the Eurasian and North American tectonic plates, earthquakes and volcanic activity are frequent in the region.

In 2021, the Fagradalsfjall volcano recorded an eruption that lasted six months and expelled gas, lava and rocks.

In this audio clip, you can listen to 24 hours of activity recorded between November 10th and 11th. Peppered with a cacophony of high-pitched banging noises, it sounds like someone is knocking insistently on a door.

“The activity is formidable, exciting and frightening,” Northwestern seismologist Suzan van der Lee, who co-developed Earthtunes, said in a press release. The app is supported by the American Geophysical Union and Northwestern’s Earth and Planetary Sciences department. Seismic data is obtained from the Earthscope Consortium.

In another audio clip distributed by the university, the sound appears increased by ten octaves. You can hear a long, low sound, punctuated by the occasional door slam.

“What we are hearing is 24 hours of seismic data – full of earthquake signals,” explains van der Lee. “The vast majority of these earthquakes are associated with the intrusion of magma into the crust of the Fagradallsfjall-Svartsengi-Grindavik area of ​​the Reykjanes Peninsula.

According to her, seismic data is not audible; their frequencies are very low. Thus, the 24 hours of data are compressed into about 1.5 minutes of audio data.

In a third audio clip, the same data is compressed less, with the pitch increased by just seven octaves.

“We can hear frequent earthquakes happening right now,” said van der Lee. “Icelandic seismologists have been monitoring these earthquakes and their increasing vigor and changing patterns. They have recognized patterns similar to the earthquake swarms that preceded the 2021-2023 eruptions of the adjacent Fagradallsfjall volcano.”

In her opinion, Iceland did the right thing by evacuating residents of nearby Grindavik and the nearby Svartsengi geothermal power plant, one of the oldest in the world. This was the first plant to combine electricity production with hot water for heating in the region.

In his research, Van der Lee applies data science to millions of seismic wave records to decode seismic signals, which hold valuable information about the dynamics of Earth’s interior.

According to her, the imminent eruption of the Fagradalsfjall volcano is reminiscent of another, that of Heimaey, which occurred in 1973, in the Vestmannaeyjar archipelago, also in Iceland. At the time, lava covered part of the city.

“This level of danger is unprecedented for this area of ​​Iceland, but not for Iceland as a whole,” said Van der Lee, who climbed Fagradalsfjall in June. A Sheet was in an area close to the volcano at the end of October. The entire region accumulates mountains of lava.

In March 2021, the Fagradalsfjall volcano erupted and attracted more than 350,000 people in the following months when it continued to be active.

The following year, in August, a new three-week eruption occurred again in the same area, followed by another in July of this year.

Before the recent episodes, Fagradalsfjall, which is about 6 km wide and 19 km long, had remained inactive for more than 6,000 years.

Van der Lee explains that most Icelandic volcanoes erupt far from cities and other infrastructure, which makes Icelanders very fearful about the current situation.

“They share the terrible memory of the eruption 50 years ago on the island Vestmannaeyjar. Residents felt very vulnerable, just as people evacuated from Grindavik feel now. In a few days or weeks, they may no longer have their jobs, homes and most possessions, while still having to feed their families and pay their mortgages.”

However, according to her, even as a result of the experience in Vestmannaeyjar, Icelanders are now well prepared for the current situation.