Magnetic Field - Secular Variation of the Inclination Component for the Epoch 2010.0
National Geophysical Data Center
This shapefile shows lines of equal annual change (secular variation) in the inclination of the Earth's magnetic field, derived from the International Geomagnetic Reference Field (IGRF) for the epoch 2010.0. Magnetic inclination is the angle between the magnetic field vector and the horizontal plane. The change is measured in arc minutes per year. 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 U.S. Geological Survey in the use of these data.