Meteotsunami

A meteorological tsunami or meteorological tsunami is a tsunami -like phenomenon that can be triggered by changes in air pressure and resonance phenomena in shallow waters. This phenomenon is known in various countries under various names. In the Balearic Islands it is called Rissaga in Malta Milghuba, Sicily Marrubio, in the Bay of Fiume Stigazzi and Japan Abiki or Yota. In the Baltic Sea (Finland ), it has also been described under the name Fur Seal.

Rissaga

Rissaga ( Resarca, Rissague ) is a hydrological phenomenon that occurs in the port of Ciutadella on the Balearic island of Menorca. It comes only once or twice before in the year and is usually weak. In some cases, however, the dock is running within a few seconds almost completely empty, the water is then returned in a huge wave and sometimes caused great damage, as on 21 June 1984 and 15 June 2006.

After studies at the University of the Balearic Islands, the water level fluctuations do not arise seismic causes and have typically nothing to do with the tides; there is much more to a sudden brief drop in air pressure to max. 8 hPa, which precede many variations in air pressure in one-minute intervals by 2 hPa.

The vibrations of the atmosphere transmit obviously on the water surface. This large water level fluctuations can occur, it requires two conditions: low water depth and a narrow bay. At a measurement point before the harbor bay Ciudadelas the water level oscillates during a Rissaga to max. 60 cm, in the bay inside to well over 2 meters.

If special meteorological factors (typically humid with overcast skies and southerly winds ) come together and a certain phase of the moon, however, it may be a high tide ( 4 meters) are similar to a tsunami. Since the beginning of the measurements the Rissaga is occurring only once in Northwind.

Recent large deposits of this effect:

• June 21, 1984: with losses running into millions of bars, restaurants and boats
• June 15, 2006: increase of four meters in a very short time, numerous boats destroyed, set bars and restaurants under water

Further populations

• June 27, 2011: An approximately one meter high tsunami washed over in South West England coastal bays and sat under water

• On 13 June 2013, a mysterious tsunami flooded over a width of more than a thousand kilometers of beaches on the east coast of the USA.