It’s been a rough winter for large swaths of North America. First, a polar vortex plunged much of the Midwest into dangerously frigid temperatures. More recently, a furious wind storm has been pummelling eastern Canada and United States, causing flight delays, school cancellations and thousands of power outages. Along the shores of Lake Erie, the gusts were so strong that blocks of ice surged over the shoreline and formed walls as high as 30 feet—a striking phenomenon known as an “ice tsunami.”
Footage released by the Niagara Parks Police showed ice piling up over a retaining wall in Fort Erie, Ontario, where homes were flooded by the rush of ice and water. In the lakeside community of Hoover Beach in New York State, the waves of ice crashed into several residential properties, prompting authorities to issue a voluntary evacuation notice.
“We've had storms in the past but nothing like this,” Hoover Beach resident Dave Schultz tells WGRZ. “We've never had the ice pushed up against the walls and right up onto our patios... it's in my patio, the neighbor's patio, and the patio after that.”
@NiagParksPolice advising that @NiagaraParks Roads Department closing Niagara River Parkway near Mathers Arch. Strong winds blowing ice over the retaining wall from the lake. Drive with caution. Video courtesy @NiagRegPolice Insp. Garvey.... pic.twitter.com/RdXh5HYxfx— Niagara Parks Police (@NiagParksPolice) February 24, 2019
Ice tsunamis—also known as “ice shoves” and “ivu,” among other names—are rare, but well-documented events. According to National Geographic’s Michael Greshko, ice tsunamis were being studied as far back as 1822, when an American naturalist commented on “rocks, on level ground, taking up a gradual line of march [along a lakebed] and overcoming every obstacle in ... escaping the dominion of Neptune.”
Today, we know that ice tsunamis tend to occur when three conditions are in place. The event is most common in springtime, when ice that covers large bodies of water starts to thaw, but has not yet melted. If strong winds then blow through the area, they can push the ice towards the water’s edge—and winds in the Lake Erie region were indeed quite powerful, reaching hurricane-like speeds of up to 74 miles per hour, reports Fox News; Travis Fedschun. The third condition is a gently sloping shoreline; the gentler the slope, the less resistance the ice meets as it piles up and pushes inland.
“The first slabs or sheets move on shore, creating a traffic jam, with ice piling on top and behind,” meteorologist Matt Grinter tells the Weather Network. “With the buildup of ice, and the power behind it, it has the potential to damage anything in its path.”
But the inhospitable and potentially dangerous weather conditions did not wholly dampen enthusiasm for the ice tsunamis.
‘‘It’s awesome! Crazy and awesome at the same time,’’ one Rose Hirshbeck of Hamburg, New York told the Associated Press as she brave biting winds to get a photo of the ice pile-up. ‘‘This is unbelievable.’’