Those rumblings felt by much of Greater Sudbury on Jan. 15 weren’t earthquakes, but they were mining related, said a spokesperson with Natural Resources Canada.
The first seismic event happened at around 9:10 p.m and measured in at 3.2 and happened about two kilometres below ground, said Stephen Crane, a research scientist at Natural Resources Canada.
The second seismic event happened around 10:20 p.m. and measured in at 3.7.
Both occurred within six kilometres north of Lively, and Crane said they confirmed the tremors with Creighton Mine.
Vale said in an email statement three seismic event happened at Creighton Mine between 9 p.m. and 10:30 p.m., measuring in a range of 2.6 and 3.7.
All employees were accounted for and brought safely to the surface. Day shift has been cancelled at Creighton Mine as "we initiate our normal seismic management protocols," said spokesperson Danica Pagnutti.
As for an exact cause, Pagnutti said it is too early to speculate and an investigation into the cause is currently underway.
Both events were widely felt, said Crane. Natural Resources Canada has received numerous reports about the seismic events from Jan. 15, and the more reports received, the better Natural Resources Canada is able to research the impact.
Greater Sudbury took to social media Friday night following the events.
"Rattled the windows at my house in Lively," said one reader on Sudbury.com.
"Just felt another tremble at 10:15 pm in New Sudbury - shook our 60-inch wall-mounted TV," said another reader.
"I am in New Sudbury and my house just shook big time from the rumble at 10:20," said a third reader.
There was also talk about cellphone signals being interrupted as a result, however, there is no indicaiton this was related to the seismic activity.