Tide gauge
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A tide gauge is a device for measuring the change in sea level relative to a vertical datum. It is also known as a mareograph, marigraph, and sea-level recorder. When applied to freshwater continental
A tide gauge
The tide gauge in Kronstadt, Russia
Interior view of Cascais Tide Gauge showing data recording equipment
Acqua alta
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An acqua alta is an exceptional tide peak that occurs periodically in the northern Adriatic Sea. The term is applied to such tides in the Italian region of Veneto. The peaks reach their maximum in the
Venice, Piazza San Marco
Venice, Campo Santa Margherita
A satellite image of the Adriatic Sea, highlighting the long and narrow rectangular shape which is the source of an oscillating water motion (called seiche) along the minor axis. The oscillation, which has a period of 21 hours and 30 minutes and an amplitude around 0.5 meters at the axis' extremities, supplements the natural tidal cycle, so that the Adriatic sea experiences much more extreme tidal events than the rest of the Mediterranean.
Acqua alta in Venice, fondamenta di Borgo, December 2019