New findings have confirmed the mysterious tremors detected on Denmark s Bornholm island were caused by acoustic pressure waves, but a mystery still remains as to what is exactly causing the phenomenon.
At first the tremors were thought to have been caused by earthquakes, but on Monday researchers said they were caused by pressure waves from "an unknown source."
COPENHAGEN, Denmark (AP) A series of minor tremors recorded on the Danish Baltic island of Bornholm Saturday has puzzled scientists, who now say they were caused by ”acoustic pressure waves from an unknown source.”
At first the tremors, which were registered on Saturday, were thought to have been caused by earthquakes. Then, seismologists theorised they came from controlled explosions in Poland