The Danish Geological Survey says that the vibration in the windows was not caused by an earthquake. Theories about the cause of the incident vary from detonation to a supersonic boom.
Something strange happened in Denmark last Saturday, May 13, at about 16:00 Finnish time: a rumbling sound and vibration of the earth’s crust were detected on the island of Bornholm.
In addition to seismographs, the event was recorded by local residents, from whom authorities received dozens of reports. The people of Bornholm have been in panic since last fall, after explosions that ruptured the Nord Stream gas pipeline were carried out in the northeast and southeast of the island.
Geuse, the national geological research institute of Denmark and Greenland, initially speculated that it was an earthquake in Poland. However, on Monday, Guice announced that the researchers could not explain the reason for the observations.
“On the morning of May 14, seismologists at GUES after a thorough investigation came to the conclusion that the vibration was not due to an earthquake. It is most likely that it was acoustic pressure waves caused by one or more events in the atmosphere,” on Monday Says Gus in the published press release.
“It was not possible for the researchers to determine what caused the strong pressure waves.”
According to Popular Mechanics online magazine, which reported on the findings, the strongest measured quake was 2.3 on the intensity scale. This can already create cracks in structures.
Guse said the researchers were able to rule out the possibility that the earthquake was caused by a “controlled explosion” in Poland on the same day and shortly before the Bornholm sighting.
GUSE lecturer Trine Dahl-Jensen, who was interviewed by the Danish news agency Ritzau at the end of the week, speculated that the earthquake was caused by a “seismic event” in the north polar region. According to Dahl-Jensen, it could have been an explosion.
The vibrations could be caused by a supersonic explosion. The photo shows a Saab JAS 39 Gripen multirole fighter aircraft in flight over Brazil on May 9. Photo: Igor do Valle / Zuma
This phenomenon was also observed in Sweden. Björn Lund, a seismologist at Uppsala University interviewed by news agency TT, thought the tremors may have been caused by military aircraft flying over the region’s airspace. According to Lund, pressure waves were observed at Olänni and Blekinge in addition to Bornholm.
– Usually, when we get reports of noises and shaking, it is almost always about Air Force planes breaking the sound barrier over the ocean. The atmospheric conditions have been such that the boom rolls from sea to land.
According to TT, a similar observation was made in the Stockholm area on 26 April. This was due to Saab’s test flights.
On Monday, the Danish Defense Forces were silent about the findings.
– Defense forces had no activity of any kind that could be linked to the earthquake on Bornholm. For more information, we ask you to contact the police, said a representative of the General Staff of Danish Radio DR.