Magnetic declination measurements in and around Iceland. Jökull 43, 45-60, 1995.
The paper describes various properties of the present geomagnetic field, including the magnetic declination which has been used for navigation purposes for many centuries. Measurements of the declination were made by various expeditions to Iceland since about A.D. 1750 or possibly earlier, but documentation on their results is scattered, and little is known of the methods used or their accuracy. Such measurements turn out to be much more useful when made at sea then on shore in Iceland, because of the large disturbing effects of magnetic remanence in local basalt rock formations.
A list of declination measurements, based on original compilations by Th. Sigurgeirsson and Th. Sæmundsson, is provided in the paper. The most valuable series of observations in the Iceland area include those of P. Löwenörn in the 1780's as well as French measurements from the period 1830-1900. The only aeromagnetic survey of Iceland for which declination values are available, is that of G.W. Haines et al. in 1965.
It is found that the westerly declination may have reached a maximum early in the 19th century. This is also in agreement with global geomagnetic reconstructions based on historical field measurements and archeomagnetism, and may be of use in dating lavas or artifacts in Iceland. The magnetic inclination appears to have been fairly constant at 75-77°.