Magnetic Field - Declination Component for the Epoch 2010.0
National Geophysical Data Center
This map layer shows isogonic lines (lines of constant declination of the Earth's magnetic field), derived from the International Geomagnetic Reference Field (IGRF) for the epoch 2010.0. Magnetic declination is the angle between true north and magnetic north (the direction of the magnetic field vector) in the horizontal plane. This layer is part of the 1997-2014 edition National Atlas of the United States.These data are intended for geographic display and analysis at the national level, and for large regional areas. The data should be displayed and analyzed at scales appropriate for 1:2,000,000-scale data. No responsibility is assumed by the National Atlas of the United States or the U.S. Geological Survey in the use of these data.