[coordinate systems]
An abbreviation of European Terrestrial Reference System 1989. An earth-centered earth-fixed geodetic Cartesian reference frame for Europe. When its datum was first defined in 1989, it was coincident with the International Terrestrial Reference System (ITRS). Because the Eurasian continental tectonic plate is largely static, ETRS89 continues to be Europe's primary reference system. In areas of the world in which tectonic plates are less static, there can be a difference of more than half a meter between ETRS89 and other reference systems such as WGS84.