Magnetic Observations in the Minusinsk Region in 1920
Abstract Generated abstract
This report describes magnetic observations made during a 1920 Tomsk University expedition in the Minusinsk region, undertaken alongside geographical and landscape studies. Using a simplified copy of Bayer’s magnetic field theodolite, the author obtained magnetic determinations at 16 points, with particular interest in a suspected anomaly near Dzhirim previously noted in the literature and by B. P. Weinberg. The account emphasizes the practical limitations of fieldwork, including repeated damage to the instrument that restricted observations to the horizontal component and ultimately halted measurements in the most promising area.
Full Text
A. K. Ivanov.
Magnetic Observations in the Minusinsk Region in 1920
In the summer of 1920 an expedition from Tomsk University took place within the limits of the Minusinsk region, composed of representatives of the Cabinet of Geography and Anthropology under the general direction of Prof. S. I. Rudenko. Carrying out the work I had planned for the investigation of the lakes of the southwestern part of Achinsk uezd, at the end of July I undertook a journey through Minusinsk uezd in order to study its landscapes. At the same time, having an assignment from the Geographical Department of the Institute for the Study of Siberia, I also made magnetic determinations at 16 points, listed in the following article by S. I. Shubin, who kindly agreed to compute the data of the observations made. The instrument with which the magnetic determinations were made was a simplified copy, No. 3, of Bayer’s magnetic field theodolite (of the Carnegie Institution).
Even before the journey I had encountered in the literature an indication by the soil scientist L. Prasolov that in the region west of the ulus of Dzhirim—“8 versts from Belyi Ius, Emel’ianov saw two conical hills, the rocks of which strongly affected the magnetic needle” (Proceedings of the Soil-Botanical Expeditions for the Investigation of the Regions of Asiatic Russia. Part I. Soil Investigations of 1910, ed. K. D. Glinka. Issue 2. L. Prasolov. A Soil-Geographical Sketch of the Northwestern Part of Minusinsk Uezd. St. Petersburg, 1914, p. 12). Prof. B. P. Weinberg, who made determinations here in 1915, also tentatively expressed the view that there was a magnetic anomaly in the Dzhirim region. Intending to investigate this interesting region in detail, I marked it for the end of the route.
Unfortunately, the conditions of travel across the steppe proved unfavorable for the fragile instrument. Despite all precautions, after the very first journey on horseback the tube proved to be damaged, and it was necessary to confine oneself only to observing the horizontal component. During the subsequent journey the stirrup for the magnet repeatedly sprang out from under the arrester, and the thread broke. It was necessary to unwind the thread again and determine its torsion, which slowed the work. Finally, after the observations in the ulus of Dzhirim, during travel in its vicinity, the only spare thread broke, and there was no longer anything with which to replace it. It was necessary to stop making observations precisely in this most interesting region.
Throughout the entire journey my active assistant was the Tomsk University student M. P. Griaznov.