The European Magnetic Declination 2006 Map shows isolines of deviation between magnetic and geographic north and is based on field measurements at 382 magnetic ‘repeat stations’ in 21 states, in the period 2005 to 2007. In addition, 42 geomagnetic observatories provided annual mean values for 2006 to enhance the spatial data density.
The map represents the magnetic declination caused by the main field and large scale influences from magnetised structures in the Earth's crust. It covers an area comprised between the meridians 13°W and 42°E and the parallels of latitude at 35°N and 72°N with a grid size of 100 km. In order to visualize the magnetic declination field over this entire region, regularly spaced grid data have to be computed from irregularly distributed measurement points in Europe.
Since no ground measurements are available over the sea, such as the Atlantic Ocean in the North and West and the Mediterranean Sea in the South, and sparse measurements in the East, declination values of the International Geomagnetic Reference Field, IGRF 2011, have been added along these border lines. The IGRF is a mathematical representation of the global magnetic field and is released by the International Association of Geomagnetism and Aeronomy (IAGA, http://www.ngdc.noaa.gov/IAGA/vmod/index.html).
The annual change of magnetic declination in Europe as obtained from the IGRF for the year 2006 is shown in the separate small map (Annual Change of Declination). An explanatory text on the
The map was plotted using the software Oasis montaj 7.2 (www.geosoft.com).
