On the afternoon of April 13, 2018, a large wave of water rushed across Lake Michigan, flooding the picturesque coastal town of Ludington, Michigan, destroying houses and docks, and submerging water inlet pipes. Thanks to photos of local residents and other data, NOAA scientists used a model to reconstruct the event and determined that this was the first meteor tsunami caused by atmospheric inertial gravity waves in a large lake.
Atmospheric inertial gravity wave is an air wave that can generate 6 to 60 miles long. It is produced when a large amount of stable air is replaced by air with a very different pressure. This causes an air current of rising and falling pressure, which may affect the water below, because it is in harmony with the two singers and synchronized with the movement of the water on the lake.
Debbie Maglothin of Ludington, who took the photos of the event, said: “The meteor tsunami was incredible.” “The water between the breakwaters did not fall like the water outside. , So it created waterfalls, which are stacked on the breakwater. If this event happens in summer, it might wash away the people on the breakwater.”
On a global scale, tsunamis generated by this type of atmospheric conditions are common, but in the Great Lakes region, there are few well-documented tsunamis that are driven by sudden strong thunderstorms and play an important role in both high winds and changes in air pressure. effect.
Combining water and weather models
Although there is currently no effective prediction model for tsunami in the United States, a new NOAA study based on the Luddington Wave shows that the existing NOAA numerical weather forecasting model and hydrodynamic forecasting model may enable scientists within minutes to hours Predict these atmospheric waves that drive meteor tsunamis. progress.The research was published in a special edition of the journal Natural hazards About meteotsunamis.
Eric Anderson, an oceanographer at NOAA’s Great Lakes Environmental Research Laboratory and lead author of the study, said: “The good news with this type of meteorological tsunami is that it is easier to predict than storms caused by thunderstorms.” Our short-term weather model can absorb these atmospheric pressure waves, and predicting thunderstorms is much more difficult.”
Meteor tsunamis are a lesser-known category of tsunamis. Unlike more famous tsunamis, such as the disastrous 2004 Boxing Day tsunami caused by an undersea earthquake in Indonesia, the tsunami is caused by the weather, especially the combined effects of changes in air pressure, strong winds and thunderstorm activities.
Anderson said: “Since the lakes are relatively small, tsunamis usually require not only a jump in air pressure, but also to drive them.” “That’s where thunderstorms and wind hit them.”
The Great Lakes have a history of meteorites
Meteor tsunamis occur all over the world. As we all know, they mainly occur on the coasts of the Great Lakes in the United States, eastern Mexico and the Gulf Coast. The Meteotsunami waves in the Great Lakes can be particularly insidious because they can bounce off the shoreline and reappear when the sky is clear. They are relatively rare and usually small, with the largest generating waves of three to six feet, about once every 10 years.
Predicting these waves in advance will give communities a potential life-saving warning and enable residents and businesses to take measures to better protect their property. The Ludington meteor tsunami caused some property damage, but did not cause serious injuries. If there is a meteor tsunami in the summer, swimmers, anglers and vacationers flock to the beaches, parks and waters of the lake shore, the situation may be completely different, just like the meteor tsunami that took the lives of eight people in Chicago in June 1954. same. .
“There is a gap between this and our prediction,” Anderson said. “Through this and other studies, we are approaching the ability to make predictions in advance.”
Pilot project warns of potentially dangerous “tsunami” waves in the Great Lakes region
Eric J. Anderson and others, the high-amplitude atmospheric inertia-gravity wave induced meteor tsunami in Lake Michigan, Natural hazards (2020). DOI: 10.1007 / s11069-020-04195-2
Provided by NOAA headquarters
Citation: Research shows that the prospect of a meteorite predicted to erupt on April 2, 2000 (April 1, 2021) comes from https://phys.org/news/2021-04-meteotsunamis.html
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