A meteotsunami or meteorological tsunamiTsunami Glossary 2008
, UNESCO is a

tsunami A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater exp ...

-like

sea wave In fluid dynamics, a wind wave, water wave, or wind-generated water wave, is a surface wave that occurs on the free surface of bodies of water as a result from the wind blowing over the water surface. The contact distance in the direction o ...

meteorological Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did not ...

origin. Meteotsunamis are generated when rapid changes in

barometric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 7 ...

cause the displacement of a body of water. In contrast to "ordinary" impulse-type tsunami sources, a traveling atmospheric disturbance normally interacts with the ocean over a limited period of time (from several minutes to several hours). Tsunamis and meteotsunamis are otherwise similar enough that it can be difficult to distinguish one from the other, as in cases where there is a tsunami wave but there are no records of an earthquake, landslide, or volcanic eruption. Meteotsunamis, rather, are triggered due to

extreme weather Extreme weather or extreme climate events includes unexpected, unusual, severe, or unseasonal weather; weather at the extremes of the historical distribution—the range that has been seen in the past. Often, extreme events are based on a locat ...

events including severe thunderstorms, squalls and storm fronts; all of which can quickly change atmospheric pressure. Meteotsunamis typically occur when severe weather is moving at the same speed and direction of the local wave action towards the coastline. The size of the wave is enhanced by coastal features such as shallow continental shelves, bays and inlets. Only about 3% of historical tsunami events (from 2000 BC through 2014) are known to have meteorological origins, although their true prevalence may be considerably higher than this because 10% of historical tsunamis have unknown origins, tsunami events in the past are often difficult to validate, and meteotsunamis may have previously been misclassified as

seiche A seiche ( ) is a standing wave in an enclosed or partially enclosed body of water. Seiches and seiche-related phenomena have been observed on lakes, reservoirs, swimming pools, bays, harbors, caves and seas. The key requirement for formation of ...

waves. Seiches are classified as a long-standing wave with longer periods and slower changes in water levels. They are also restricted to enclosed or partially enclosed basins.

Characteristics

Meteotsunamis are restricted to local effects because they lack the energy available to significant seismic tsunami. However, when they are amplified by resonance they can be hazardous. Meteotsunami events can last anywhere from a few minutes to a couple of hours. Their size, length and period is heavily dependent on the speed and severity of the storm front. They are progressive waves which can affect enclosed basins and also large areas of coastline. These events have produced waves over six feet in height and can resemble

storm surge A storm surge, storm flood, tidal surge, or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low-pressure weather systems, such as cyclones. It is measured as the rise in water level above the ...

flooding.

Frequency of events

In April 2019,

NOAA The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...

determined that 25 meteotsunamis, on average, impact the Eastern Seaboard of the United States every year. In the Great Lakes, even more of these events occur; on average, 126 times a year. In some parts of the world, they are common enough to have local names: ''rissaga'' or ''rissague'' (

Catalan Catalan may refer to: Catalonia From, or related to Catalonia: * Catalan language, a Romance language * Catalans, an ethnic group formed by the people from, or with origins in, Northern or southern Catalonia Places * 13178 Catalan, asteroid #1 ...

), ''ressaca'' or ''resarca'' ( Portuguese), ''milgħuba'' ( Maltese), ''marrobbio'' or ''marrubio'' (

Italian Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance language *** Regional Ita ...

), ''Seebär'' (

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

), ''abiki'' or ''yota'' ( Japanese), ''šćiga'' ( Croatian). Some bodies of water are more susceptible than others, including anywhere that the natural resonance frequency matches that of the waves, such as in long and narrow bays, particularly where the inlet is aligned with the oncoming wave. Examples of particularly susceptible areas include Nagasaki Bay, the eastern

Adriatic Sea The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Sea) to th ...

, and the Western Mediterranean.

Examples of known events

Other notable events

In 1929, a wave 6 meters in height pulled ten people from the shore, to their deaths in Grand Haven, Michigan. A three-meter wave that hit the Chicago waterfront in 1954 swept people off of piers, drowning seven. A meteotsunami that struck Nagasaki Bay on 31 March 1979 achieved a maximum wave height of 5 meters; there were three fatalities. In June 2013, a

derecho A ''derecho'' (, from es, derecho, link=no , 'straight') is a widespread, long-lived, straight-line wind storm that is associated with a fast-moving group of severe thunderstorms known as a mesoscale convective system. Derechos can cause hurri ...

off the New Jersey coast triggered a widespread meteotsunami event, where tide gauges along the East Coast, Puerto Rico and Bermuda reported "tsunami-like" conditions. The peak wave

amplitude The amplitude of a periodic variable is a measure of its change in a single period (such as time or spatial period). The amplitude of a non-periodic signal is its magnitude compared with a reference value. There are various definitions of am ...

was 1 foot above normal sea level in Newport, RI. In New Jersey, divers were pulled over a

breakwater Breakwater may refer to: * Breakwater (structure), a structure for protecting a beach or harbour Places * Breakwater, Victoria, a suburb of Geelong, Victoria, Australia * Breakwater Island, Antarctica * Breakwater Islands, Nunavut, Canada * Br ...

and three people were swept off a jetty, two seriously injured, when a six-foot wave struck the

Barnegat Inlet Barnegat Inlet is a small inlet connecting the Barnegat Bay with the Atlantic Ocean in Ocean County, New Jersey. It separates Island Beach State Park and the Barnegat Peninsula from Long Beach Island. The Barnegat Lighthouse sits at the northern ...

References

External links

*
Photos of the Rissaga in Spain (Ciutadella) 06-15-2006

Video of a meteotsunami at Sanibel Island, Florida
{{physical oceanography Weather hazards Flood Tsunami Water waves