In ancient times man considered celestial phenomena to be signals from supernatural forces and signs of forthcoming calamitous or unusual events. Science has removed the mystical shroud from many natural phenomena, and the modern educated man can only wonder at the naivety of his forebears. He who has seen, if only once, the shimmering colors of the northern lights will say that there is no other atmospheric phenomenon that is as beautiful and impressive. But in what way is aurora borealis related to the structure of the Earth?The appearance of northern Lights results from the collision between charged particles streaming from the Sun with molecules and atoms in the Earth’s atmosphere. The energy of the particles is transformed into electromagnetic radiation. A portion of this energy lies in the region of the visible spectrum and can be perceived by the human eye as a luminous aureole. The intensity, color, shape, and duration of the aurora displays depend on the Sun’s activity, while the spatial distribution of the lights and the frequency of auroras reflect the heterogeneous nature of the Earth’s magnetic field.
Ideally, if the Earth had a homogeneous magnetic field, the Frequency of the appearance of aurora borealis would depend on the latitude only. The maximum would then appear in the Arctic region 20° below the magnetic poles, where the density of the flow of charged particles is at a maximum. However, the real picture is much more complex.
For a long time attempts were made to draw isochasms, or lines that have the same number of auroras in the year. Scientists have found a number of major anomalies on the territory of the USSR, for example, in the Yakutsk Region. And minor anomalies have been observed within the boundaries of one region. The view has been voiced that these anomalies are caused by the peculiarities in the geological structure of the corresponding regions.
This hypothesis has been put forward by scientists at the Siberian Institute of Earth Magnetism, Ionosphere and the Distribution ol Radio Waves, the Siberian Branch of the USSR Academy of Sciences, who have for several years photographed the night sky in the vicinity of Norilsk. As a result, they have been able to compile a map of isochasms and identify several anomalies. These anomalies could neither be explained by the structure of the terrain, nor by man’s economic activity.
A comparison of this map with known data on the geology of the region shows that the anomalies correspond to the contours of the Norilsk ore-bearing plateau and the boundaries of the Siberian plateau—a huge heavy mass of the Earth’s crust occupying nearly the whole of the West Siberian depression. The obtained results accord with the hypothesis on the relation between aurora borealis and the structure of the Earth’s crust.
Unquestionably, the subject requires further study, especially in regions whose geology has been thoroughly investigated (such as the Kola Peninsula in the USSR).
Published in: Yu. Krakovctsky, Yu. Nadubovich, et al. – An Investigation of the Spatial Distribution of Northern Lights, Doklady ANSSSR, Vol. 279, No. 3, 1984.