Seismic waves vibrated off an island near Africa and hit Canada. Their cause is a mystery

If seismic waves emerge near an island off Africa and hit Canada, does anyone feel it?

Apparently not – judging by a phenomenon that materialized earlier this month.

Earthquake coverage on Globalnews.ca:

The unusual seismological phenomenon originated on November 11 near the island of Mayotte, off Madagascar.

They were detected very early by @matarikipax, a Twitter user, who published data from the US geological survey showing that they were detected at a monitoring station in Kilima Mbogo, Kenya.

The same user tweeted that waves had also been detected in Zambia, Ethiopia, Spain and New Zealand.

John Cbadidy, a seismologist specializing in earthquakes at Natural Resources Canada (NRCan), later joined the fray, claiming the waves had been detected across Canada in Victoria, Haida Gwaii, Toronto, Ottawa and Halifax.

Clearly, the waves have been spotted all over the planet.

But no one seems to have felt them, even at the beginning, and that gave them an aura of mystery, Cbadidy told Global News.

Nobody can explain exactly why they happened.

READ MORE: A magnitude 6.8 earthquake hits the Greek tourist island

Normally, a tectonic earthquake generates primary waves (P waves) and secondary waves (s waves), but this has not been produced either.

The ground was rising and falling every 17 seconds when the waves broke – "very slowly, shaking," Cbadidy said.

It is possible that an earthquake occurred, but if it happened, the event was certainly not a "typical" event, he added.

"On the basis of seismic events and GPS training data, there is probably a volcanic link – the movement of magma chambers, etc.," said Cbadidy.

Seismic waves originated in an area where a "swarm of earthquakes" occurred earlier this year.

Mayotte, formed by volcanic activity, recorded "several hundred seismic events" in the area from May, according to the French surveyor BRGM.

The first took place on May 10th. Then, five days later, the neighboring island of Comoros suffered an earthquake of magnitude 5.8, the largest ever recorded.

Other seismic events have occurred in the area, but have declined since July.

"This indicates that the seismic energy released has weakened since the beginning of the crisis, although some earthquakes continue to be felt by the population," BRGM said.

The cause of the swarm is still under study, but the researchers believe it could be a combination of tectonic and volcanic effects – although this has not yet been confirmed.

The interior of British Columbia experienced a swarm of earthquakes in 2007, after never having recorded earthquakes in the past.

The swarm was attributed to the injection of magma into the lower crust of the Anahim volcanic belt, a phenomenon that produces "high-frequency volcanic tectonic earthquakes and spasmodic bursts".

READ MORE: 3 magnitude 6.5 and 6.8 earthquakes affected Vancouver Island

If volcanic activity was confirmed near Mayotte, it would be the first time this region had settled in the region for more than 4,000 years.

And that's important for Western Canada, Cbadidy said, in which a number of volcanoes have also been dormant for thousands of years and could be reactivated in the future.

"Understanding these signals from Mayotte will help us better understand the volcanic risks here in Canada," he said.