Metres above the Adriatic

The Adriatic datum

Metres above the Adriatic (German: Meter über Adria)^[1] is an elevation reference system used in Austria and some other European countries based on the average water level of the Adriatic Sea at the Molo Sartorio in Triest harbour. Whilst the former Yugoslavian states still use this datum, in 1945 the former Austro-Hungarian states in the Eastern Block switched to the Kronstadt Gauge.

Abbreviation

The individual countries using this datum abbreviate it in different ways depending on their local language, as follows:

• Austria: m ü. Adria, m.ü.A. or müA, colloquially known as Seehöhe or Adriahöhe
• Hungary: mAf from méter Adria felett
• Former Yugoslavian states: m. i. J. from Metara iznad Jadrana

Gauge

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 (the Durrës Gauge) as the datum.

Height differences between Austria and its neighbours

In Austria orthometric height is used. Austria's neighbours use other height systems which leads to differences between the heights. On the state borders these differences are:

• Germany: +25 to +34.6 cm (normal-orthometric height – Amsterdam Tide Gauge – Normalnull)
• Italy: −0.5 to −3.2 cm (orthometric height – Genua Tide Gauge)
• Switzerland: −1.6 to −7.5 cm (orthometric height – Marseille Tide Gauge – Metres above the Sea (Switzerland))
• Slovakia: +57 cm (normal height – Kronstadt Tide Gauge)
• Slovenia: −8 to −12 cm (normal-orthometric height – 1900 Trieste Tide Gauge)
• Czech Rep.: +46 to +56.3 cm (normal height – Kronstadt Tide Gauge) and
• Hungary: +49.6 to +60.6 cm (normal height, hungarian Tengerszint feletti magasság – Kronstadt Tide Gauge).

(Differences: H_Austria − H_{neighbouring states})^[2]

See also

	Geography portal
	Austria portal

• Metre
• Normalhöhennull (NHN) (equivalent in Germany)
• Metres above the Sea (Switzerland)

References

1. ^ May be abbreviated in English to m AA.
2. ^ Map with height differences by the Austrian Federal Office for Metrology and Survey (Bundesamt für Eich- und Vermessungswesen)

External links

• Geodätisches Institut Zagreb (mainly Croatian, partly English)

Coordinates: 45°38′49″N 13°45′36″E / 45.646867°N 13.759867°E / 45.646867; 13.759867