A weather-created wave called a meteotsunami hit a Florida beach last week, causing water levels to rise about 2 ½ feet according to the National Weather Service.
While a meteotsunami is similar to a tsunami in that it is an unusual rise in water levels, the way the two events are created is different.
A tsunami happens due to seismic activity. The 2004 Boxing Day tsunami followed a 9.1 magnitude earthquake that stuck off the coast of Sumatra. The tsunami produced by the earthquake reached up to 100 feet high and killed an estimated 227,898 people in 14 countries.
What happened in Florida last week, a meteotsunami, is not created by an earthquake, but by a strong weather system’s interaction with the shore, according to the National Oceanic and Atmospheric Administration.
“Meteotsunamis are driven by air-pressure disturbances often associated with fast-moving weather events, such as severe thunderstorms, squalls, and other storm fronts,” according to NOAA. “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.”
The meteotsunami on Clearwater Beach occurred just before 2 p.m. Wednesday as heavy rains began to move onshore, according to the Tampa Bay Times. Water levels peaked at about 5 ½ feet – the expected water level plus the water level increase from the meteotsunami, according to NOAA.
“A lot of times when that happens — you get squall lines like that or there’s a big cluster of storms that come in — they produce so much wind that you end up with a little push of a foot or two ... of extra water on top of the tide briefly,” Paul Close, a senior meteorologist at the National Weather Service’s Tampa Bay office told the Times.
The weather service does not issue specific advisories for meteotsunamis.
Meteotsunamis are seen along the East Coast, the Gulf of Mexico and in the Great Lakes, according to the National Weather Service.
Some notable U.S. meteotsunamis include:
- May 27, 2012—Lake Erie: A seven-foot wave hit the shoreline near Cleveland, Ohio, sweeping beach-goers off of their feet and swamping boats in harbors.
- October 28, 2008—Boothbay Harbor, Maine: A series of waves up to 12 feet high emptied and flooded the harbor at least three times over 15 minutes, damaging boats and shoreline infrastructure.
- July 3, 1992—Daytona Beach, Florida: A 10-foot wave crashed onto shore shortly before midnight, injuring 75 people, damaging 100 vehicles, and causing property damage. If the wave had hit hours later, during July 4th festivities, the effects could have been much worse.
- June 26, 1954—Lake Michigan: A 10-foot wave struck the shoreline near Chicago, Illinois, sweeping several people off piers. Seven lives were lost.