Scientists studying suspected Lake Superior meteotsunami that left residents 'in awe'

Michelle Allan · CBC News

· Posted: Jun 26, 2025 4:00 AM EDT | Last Updated: 10 minutes ago

Alan Auld of Shuniah, Ont., said he stepped retired to look astatine Lake Superior connected Saturday and was among radical who saw the waters receding — thing helium compared to the draining of a bathtub. 

"At archetypal we joked to everyone saying, 'Who pulled the plug?'" said Auld. 

"To spot Lake Superior, the largest freshwater water successful the world, tin bash thing similar that, that's rather powerful. So we were successful awe."

On the eastbound borderline of Thunder Bay, Shuniah is simply a municipal township along Lake Superior's bluish shoreline.

The monolithic fluctuations successful h2o levels have also intrigued aggregate scientists, who think the country experienced a meteotsunami — a benignant of tsunami question that can origin h2o levels near shorelines to emergence and autumn rapidly. 

While accepted tsunamis are caused by seafloor question similar earthquakes, meteotsunamis are linked to fast-moving weather conditions specified arsenic thunderstorms. 

A large alteration successful aerial unit accompanied with precocious upwind speeds tin play into generating a meteotsunami wave, said Eric Anderson, an subordinate prof astatine the Colorado School of Mines who has been studying meteotsunamis for implicit a decade. 

Anderson said researchers are analyzing atmospheric conditions and water-level information to fig retired what happened past weekend. 

"We person capable grounds to accidental that this was a meteotsunami-like event," helium said. 

In bid to officially corroborate it was a meteotsunami, Anderson said, researchers request to make a machine exemplary that simulates however the waves determination astir wrong the lake, which volition instrumentality immoderate time.  

Seiche oregon meteotsunami?

Auld and others who saw the water-level fluctuations thought it was a seiche. 

Anderson said a seiche is simply a lasting question that oscillates, similar h2o sloshing backmost and distant successful a bathtub. In Lake Superior, a seiche play would past astir 8 hours, helium said.

Anderson said the lawsuit Saturday occurred excessively accelerated to beryllium a seiche and was much accordant with a meteotsunami. 

He said meteotsunamis are propagating waves that determination done the water — like a question that starts astatine 1 extremity of the water and ends astatine another — and person a overmuch quicker timeframe, lasting minutes to an hr oregon two. 

On Saturday, water-level gauges recorded changes of tens of centimetres to a metre on Lake Superior, the researcher said.

"That's a immense magnitude of h2o change. This is simply a large one." 

It's uncommon for a meteotsunami of that standard to hap connected Lake Superior — it occurs perhaps a mates of times a decennary astatine most, Anderson said. While he's not alert of immoderate fatalities oregon damage, helium said Saturday's lawsuit could person easy resulted successful drownings.  

"This is benignant of connected par with our astir catastrophic" meteotsunamis, helium said. 

Meteotsunamis dangerous: experts

While rare, it's important for radical to beryllium alert of meteotsunamis due to the fact that they tin beryllium dangerous, said Chin Wu, a prof astatine University of Wisconsin successful Madison who has expertise successful meteotsunamis. 

Wu said determination person been aggregate incidents of meteotsunamis resulting in fatalities. People connected beaches and piers tin beryllium swept distant during periods of h2o level fluctuation, helium added. 

"The imaginable dangers are the h2o levels fluctuating backmost and forth, peculiarly erstwhile the h2o levels go up and spell down arsenic I spot successful the video. Once the h2o level goes down, they volition resistance the radical retired of the beaches and origin drownings." 

He warns against going to beaches and shorelines amid thunderstorms oregon accelerated changes successful h2o levels. 

Researchers are inactive trying to fig retired however to forecast erstwhile meteotsunamis mightiness happen, Wu said.

"Similar to tornadoes, we privation to marque definite we tin ever forecast this benignant of a unsafe lawsuit and pass radical up of time."