What is a seiche?

AccuWeather's Melissa Constanzer explains what a seiche is and why it's important to know what causes it to happen.

Transcript

00:00On Lake Superior last Saturday the water drained so fast out of this bay that it

00:09left boats sitting on the mud. This was during a seiche. It was experienced all

00:14around Lake Superior from the east side like you see here to the west side in

00:17cities like Duluth. But what is a seiche and what caused it? Seiches are actually

00:23when enclosed bodies of water sloshed back and forth. You can think of your

00:27bathtub or swimming pool. If you push all of the water to one side and then let

00:31go the water would continue to slosh back and forth. The same can actually happen

00:35to lakes but on a larger scale. So what causes them? It may seem like only

00:40earthquakes could cause such a phenomenon but in this case it was actually the

00:43weather. The deadly storms that produce tornadoes and greater than 100 mile per

00:48hour wind gusts in North Dakota last Friday continued across Lake Superior

00:51moving to the east. Saturday morning those storms with their winds acted like a

00:56wall pushing all the water to the east end of Lake Superior. Then the rest of

01:01Saturday the lake continued to slosh back and forth. You can actually see the

01:05changes on the water level measurements taken around the lake. At Point Iroquois in

01:09Michigan the lake levels changed by almost four feet in three hours. That's

01:14much greater than their typical tidal fluctuations that you see here. And on the

01:18west side of Lake Superior Duluth's levels changed by about a foot and a half and it

01:22was enough here to create some challenges for boaters getting in and out of the

01:27harbor. Many of the Great Lakes like Lake Ontario and Lake Erie experienced

01:31stations. In 1844 a famous Lake Erie station of 22 feet pushed over a seawall

01:37killing 78 people. It also dammed up Niagara Falls with so much ice that the

01:42falls temporarily stopped flowing. Outside of the Great Lakes smaller bodies of

01:46water can have stations too. Lake Pontchartrain can have stations when thunderstorm

01:50squall lines move through. Also they're found in Lake Geneva in Switzerland.