Metres above the Adriatic

Metres above the Adriatic (Italian: Metri sopra l'Adriatico, German: Meter über Adria, Croatian: Metara iznad Jadrana) is the mean sea level datum used in Austria and some other Central and Southeast European countries to measure elevation referring to the average water level of the Adriatic Sea at the Sartorio mole in the Port of Trieste.

The gauging station in the Port of Trieste was established in the 19th century by the local observatory run by the military geographical institute of the Austro-Hungarian Army. The average water surface elevation at Molo Sartorio became the datum valid for the whole Austro-Hungarian monarchy. Whilst the former Yugoslavian states still use it, the Eastern Bloc successor states of Austria-Hungary like Hungary and Czechoslovakia after World War II switched to the Kronstadt Gauge of the Baltic Sea, which is 0.6747 m (2.214 ft) higher.

Whilst for Austria the 1875 gauge is used as the datum, the regions of the former Yugoslavia use the 1900 gauge (Nadmorska visina, m/nv). In Albania (normal-orthometric height) they also refer to heights as 'metres above the Adriatic', but use a specific tide gauge in the port of Durrës.

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