Ice atop a frozen lake can be serene and peaceful. But when that ice leaps onto land with explosive force, as it did Sunday on the eastern shores of Lake Erie, the results can be terrifying.
Some watched in awe and others in horror as what appeared to be a tsunami of ice crashed ashore in Mather Park, over the Peace Bridge in Canada across from Buffalo.
A similar scene unfolded seven miles south in Hamburg, N.Y. Ten-foot ice mountains threatened homes and businesses along North Shore Drive in Hoover Beach, prompting police to issue a voluntary evacuation order.
Winds blowing along Lake Erie reached impressive force in response to a developing storm system to the north. A gust of 80 mph was clocked at Oswego, 74 mph at Niagara Falls and 72 at Hamburg, while winds peaked at 69 mph in Buffalo. But it wasn’t just that the wind was blowing — it was what the wind was blowing. With 241 miles of room to gallop, the ice on the surface of the lake began to gain momentum.
The ice had nowhere to go when it crunched up against the coastline in Chautauqua, Erie and Niagara counties. Sunday’s weather also featured another unusual wild card: a seiche.
Seiches are akin to meteotsunamis, except they occur over an enclosed body of water. A seiche is a sudden change in water level, usually in response to a change in atmospheric pressure. When air is added or removed over part of a large lake, the water surface either bulges up or is forced down. It’s like blowing down on one side of a bowl of soup — the liquid is displaced, depressed on one side and rising on the other.
Data suggests that’s what happened at noon Sunday. In 12 minutes, the temperature at Sturgeon Point, N.Y., fell 12.2 degrees, from nearly 50 degrees to the mid-30s. It was the third time in two hours that a temperature fluctuation of at least 10 degrees had occurred. At the same time, air pressures rose as cooler, denser air piled up on the ground.
Over the next 2½ hours, the water level rose 4.13 feet. The cold air draining down from Canada on the heels of damaging winds had displaced water from the western side of the lake. It wasn’t abrupt, like a meteotsunami, as seiches are gentler and have a time scale of several hours.
But the ice didn’t lurch onto land over several hours — it did it in seconds. That’s because the seiche probably triggered a Kelvin wave, which occurs along a boundary and is influenced by the Coriolis force. That means Earth’s rotation plays a role. In smaller lakes, this can’t occur, but Lake Erie is large enough that it “feels” the spinning globe.
That probably would have sent a wavefront zipping along the rim of the lake, plowing ice onshore as it ripped through. It would calm over time, which is why the Kelvin wave probably didn’t make it the entire way around. Where it did, it whipped chunks of ice into mounds six to eight feet tall.
It’s not the first time that something like this has happened. On May 11, 2013, seven homes were destroyed by a massive ice pileup in Ochre Beach on the southwest side of Dauphin Lake in Manitoba, Canada.