Meteotsunamis on the Great Lakes? Here’s what they are and how they form

In April 2018, two meteotsunamis formed on Lake Michigan on the same day. It’s a rare occurrence, but not as rare as you may think -- especially on the Great Lakes.

According to the NOAA Great Lakes Environmental Research Laboratory, two meteotsunamis formed on April 13, 2018, near Ludington while bands of thunderstorms pushed across northern Lake Michigan.

NOAA’s Great Lakes Environmental Research Laboratory (GLERL) released a modeling of the meteotsunamis in a tweet that week. See below:

"The meteotsunami was caused by those short, extreme bursts of wind and pressure," said the GLERL. "A meteotsunami is an isolated area of water rising (like a long singular wave). It’s caused by a very strong, defined line of storms. And it’s a blip, timewise – it’s usually tens of minutes long, or no more than two hours."

What is a meteotsunami?

According to NOAA, meteotsunamis are large waves that scientists are just beginning to better understand. Unlike tsunamis triggered by seismic activity, meteotsunamis are driven by air-pressure disturbances often associated with fast-moving weather events, such as severe thunderstorms, squalls, and other storm fronts. The storm generates a wave that moves towards the shore, and is amplified by a shallow continental shelf and inlet, bay, or other coastal feature.

Meteotsunamis have been observed to reach heights of 6 feet or more. They occur in many places around the world, including the Great Lakes, Gulf of Mexico, Atlantic Coast, and the Mediterranean and Adriatic Seas.

Identifying a meteotsunami is a challenge because its characteristics are almost indistinguishable from a seismic tsunami. It can also be confused with wind-driven storm surge or a seiche. These uncertainties make it difficult to predict a meteotsunami and warn the public of a potential event. However, NOAA scientists have identified atmospheric conditions that are likely to generate a meteotsunami and continue to work on ways to forecast them.

Are they dangerous on the Great Lakes?

Scientists explained this phenomenon in detail in February 2018 at an American Geophysical Union conference. (Watch the full video below)

"These are unusually fast changes in water level that can catch people off guard and inundate the coast, damage waterfront property, disrupt maritime activities and create strong currents," researchers said at the conference.

According to the University of Michigan's Cooperative Institute for Great Lakes Research, large occurrences have had destructive impacts on property and life on the Great Lakes.

"Although many meteotsunamis are too small to notice, large meteotsunamis can have devastating coastal impacts (damaging waves, flooding, strong currents) that cause significant damage, injury and death. Meteotsunamis are frequently observed in the Great Lakes, averaging 106 events per year."

"Furthermore, sudden and unexpected water level drawdown due to meteotsunamis could cause dry intakes, leading to insufficient water supply and endangering the safety of nuclear power plants in the Great Lakes. While the hazards that meteotsunamis pose the Great Lakes and U.S. oceanic coastlines has been recognized, a reliable warning system for forecasting meteotsunamis has yet to be developed."

Meteotsunamis: An overlooked hazard for the Great Lakes and beyond