Magnetic card for the declination to 2015.0
The role of the national magnetic grids is to allow the creation of a cartography which shows the earth's magnetic field expressed by the value of its elements and their temporal variation on a map. Since 1980, the National Institute of Geophysics and Volcanology has systematically carried out measurements of the earth's magnetic field.
Currently, the Italian Magnetic Network consists of 120 stations, called cornerstones, distributed as uniformly as possible throughout the country. At each of these stations, measurements of the elements of the magnetic field are carried out, on average every 5 years. These measurements make it possible to determine:
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the spatial variation of the earth's magnetic field through the creation (in collaboration with the Military Geographical Institute of Florence) of a cartography which shows on a map the field expressed by the value of its elements for the various measurement periods; li dir="ltr">the values of the coefficients of the equations of the normal field (meaning by normal field the main field that originates in the earth's nucleus) expressed in polynomial form of the second order in latitude and longitude;
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the spatial characteristics, usually greater than the national dimensions, of the temporal variation of the earth's magnetic field, identified with the term secular variation, through the exchange of data coming from national networks with other countries (the Mag.Net organization operates at a European level .E., acronym for Magnetic Network in Europe).
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The magnetic data collected during the measurement campaigns at the appropriately processed cornerstones allow the creation of a cartography in which the magnetic field expressed by the value of its elements as well as their temporal variation is reported on a map. These maps are produced with a five-year deadline.
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The last magnetic card for Italy (related to the year 2015) was created as part of the collaboration between the National Institute of Geophysics and Volcanology (INGV) and the Italian Military Geographic Institute (IGM). Compiled in four sheets on the basis of magnetic measurements carried out on 133 strongholds of the Italian Magnetic Network (including 2 Observatories, 11 strongholds in Albania and 3 strongholds in Corsica) it describes the values of the magnetic elements D, H, Z as well as the intensity F for the 'Italy, for the year 2015.0, on a scale of 1:2000000.
This card is available in both paper and electronic formats.