Sao Paulo
The impending eruption of the Fagradalsfjall volcano on the Reykjanes Peninsula in Iceland has attracted worldwide attention and now the seismic activity that precedes it can be followed via audio.
Researchers at Northwestern University in the US have developed the Earthtunes application, which converts seismic frequencies into audible sounds.
While a classic seismograph records movements on the earth’s surface as wavy lines drawn on a page, Earthtunes allows users to hear this activity instead of seeing it, says a statement from the university this Thursday (16).
So far, the recent and ongoing seismic activity in Iceland has sounded like a kind of loud symphony of slamming doors, hail pelting a tin roof or window, and people breaking trays of ice cubes.
Since midOctober, seismic activity has become increasingly frequent and intense. The report from Sheet He was in Iceland between October 17th and 30th and received daily warnings from the Icelandic Meteorological Service about earthquakes around the Fagradalsfjall area from October 25th.
Until then, however, they had not been linked to an impending volcanic eruption. Since the area lies between the Eurasian and North American tectonic plates, earthquakes and volcanic activity are common in the region.
In 2021, the Fagradalsfjall volcano experienced an eruption that lasted six months and spewed gas, lava and rock.
In this audio clip you can listen to 24 hours of activity recorded between November 10th and 11th. Peppered with a cacophony of highpitched knocks, it sounds like someone is knocking persistently on a door.
“The activity is impressive, exciting and frightening,” Northwestern seismologist Suzan van der Lee, who codeveloped Earthtunes, said in a news release. The app is supported by the American Geophysical Union and the Department of Earth and Planetary Sciences at Northwestern University. Seismic data is obtained from the Earthscope Consortium.
In another audio clip distributed by the university, the sound appears raised ten octaves. A long, deep noise is heard, 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 magma intrusion into the crust of the FagradallsfjallSvartsengiGrindavik area the Reykjanes Peninsula.
In their opinion, seismic data is not audible; their frequencies are very low. So the 24 hours of data is compressed into about 1.5 minutes of audio data.
In a third audio clip, the same data is compressed less, with the pitch only increased by seven octaves.
“We can currently hear frequent earthquakes,” van der Lee said. “Icelandic seismologists have been monitoring these earthquakes and their increasing strength and changing patterns. They have detected patterns similar to the earthquake swarms that preceded the 20212023 eruptions of the adjacent Fagradallsfjall volcano.”
In their 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 in the region to combine electricity generation with hot water for heating.
In his research, Van der Lee applies data science to millions of seismic wave recordings to decipher seismic signals that contain valuable information about the dynamics of the Earth’s interior.
According to her, the upcoming eruption of the Fagradalsfjall volcano is reminiscent of another, that of Heimaey, which occurred in 1973 in the Vestmannaeyjar archipelago, also in Iceland. At that time, lava covered part of the city.
“This level of danger is unprecedented for this region of Iceland, but not for Iceland as a whole,” said Van der Lee, who climbed Fagradalsfjall in June. A Sheet was near the volcano at the end of October. Mountains of lava are accumulating throughout the region.
In March 2021, the Fagradalsfjall volcano erupted, attracting more than 350,000 people in the following months, during which it continued to be active.
The following year, in August, another threeweek eruption occurred in the same area, followed by another in July of that year.
Before the recent episodes, the approximately 6 km wide and 19 km long Fagradalsfjall had remained dormant 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 afraid of the current situation.
“They share the terrible memory of the eruption 50 years ago on the island of Vestmannaeyjar. The residents felt very vulnerable, just as the people evacuated from Grindavik feel now. In a few days or weeks, they may no longer have their jobs, their homes, and most of their possessions, while still having to feed their families and pay their mortgages.”
But in her opinion, the Icelanders are now well prepared for the current situation, also based on the experience in Vestmannaeyjar.