Inclination I
Angle between the geomagnetic field and the local horizontal plane. Also the angle between a remanent magnetisation of a sample and the horizontal plane.



Induced magnetisation

Magnetic moment per unit of volume (A/m) or per unit of weight (Am
2/kg) of a magnetised sample, measured in the presence of a inducing magnetic field. The induced magnetisation is the sum of two components: the remanent magnetisation (magnetisation that remains when the magnetic field is removed) and the transient magnetisation (magnetisation that disappears when the magnetic field is removed).


in-situ
The term in situ means, to an archaeomagnetist, unmoved since it acquired its original magnetisation – whether deliberately or accidental. It is thus far more specific than for an archaeologist for which the terms usually means that the object is not foreign, i.e. from outside the site.



Intensity F, M
The value or magnitude F of the geomagnetic field expressed in Tesla. Also the value or magnitude M of the
remanent magnetisation of a sample expressed in A/m or Am2/kg.



International geomagnetic reference model (IGRF)
Model for the global
geomagnetic field of internal origin. It is based on a global spherical harmonical analysis and takes also  temporal variations of the field into account. Calculate the geomagnetic field at your location for certain year: http://nssdc.gsfc.nasa.gov/space/model/models/igrf.html!



Iron-age
Denotes a time period in the development of the human society when iron working was the most sophisticated form of metalworking. Its hardness, high melting point and the abundance of iron sources favoured its use. The Iron-age is subsequent to the Bronze-age. The Iron-age lasted in Britain from around 500 BC to 500 AD or until the Roman conquest (43 AD – 303 AD). In central Europe it lasted from about 800 BC until the Roman conquest.



Isothermal remanent magnetisation (IRM)
Remanent magnetisation acquired by a sample after the application of a constant or steady magnetic field and removal of the field.