"I can't remember seeing a similar sequence of earthquakes at the mine there during the 20 years that we've had a pretty decent seismic network," seismologist Björn Lund told P4 Dalarna.
The miners are now working on the surface, including planning work. Popping sounds from underground have been heard at the surface and tremors have been felt, but the area is considered safe.
On Saturday evening, Boliden's mine in Garpenberg was evacuated after high seismic activity was detected. Earlier that day, four people were slightly injured in a landslide.
It is unclear how long the mine will be closed.
