Seiche

Wind and weather conditions on the Great Lakes may create a seiche, an oscillating wave which can be several feet high.

A seiche is a standing wave oscillating in a body of water.

If you have observed water sloshing back and forth in a swimming pool, bathtub, or cup of water, you may have witnessed a small-scale seiche.

Lake Erie is known for seiches, especially when strong winds blow from southwest to northeast. In 1844, a 22-foot seiche breached a 14-foot-high sea wall killing 78 people and damming the ice to the extent that Niagara Falls temporarily stopped flowing.

In some of the Great Lakes and other large bodies of water, the time period between the "high" and "low" of a seiche can be as much as four to seven hours. This is very similar to the time period between a high and low tide in the oceans, and is often mistaken as a tide.

In September 2023, we detected the start of a 9-day-long, global . . . very-long-period seismic signal, originating from East Greenland. . . .this event started with a glacial thinning-induced rock-ice avalanche of 25 million cubic meters plunging into Dickson Fjord, triggering a 200-meter-high tsunami. Simulations show that the tsunami stabilized into a 7-meter-high long-duration seiche with a frequency. . .and slow amplitude decay that were nearly identical to the seismic signal. An oscillating, fjord-transverse single force . . . reproduced the seismic amplitudes and their radiation pattern relative to the fjord, demonstrating how a seiche directly caused the 9-day-long seismic signal.