Magnetic Observatories

research establishments in which time variations in the earth’s magnetic field are recorded continuously and regular measurements are made of the absolute values of the intensity and direction of the geomagnetic field.

Magnetic observatories are equipped with various types of magnetographs and magnetometers. They are usually set up at a distance from cities, electrified railroads, and large industrial enterprises, all of which can distort the geomagnetic field. A number of the observatories are part of magneto-ionospheric stations.

The data obtained by magnetic observatories are used in studying the behavior of the geomagnetic field, which is a sensitive indicator of the complex processes that take place in the earth’s magnetosphere, ionosphere, and interior. Moreover, they are used in terrestrial and aeromagnetic surveying to record magnetic variations and to organize the results of measurements made at different times into periods. Magnetic observatories are also used to check the field magnetometers used in mineral prospecting.

The first magnetic observatories in Europe had been built in St. Petersburg and Kazan by 1829. Subsequently, observatories were built in Nerchinsk, Barnaul, Kolyvan’, Ekaterinburg, and Tbilisi. The first polar magnetic observatory in the world was opened in 1924 in the straits of Matochkin Shar on Novaia Zemlia. The Institute of Geomagnetism, an outgrowth of the magnetics department of the Main Geophysical Observatory, was established near Moscow in 1939. As of 1972 the USSR was operating more than 40 magnetic observatories, including several in the polar regions (the arctic and antarctic).

There are more than 130 permanent magnetic observatories in the world, including facilities in Vienna, Nantes, Sitka (Alaska), and Honolulu. However, their distribution is extremely uneven. Most of them are in Europe, and the fewest are found on the oceans and seas. Information on the earth’s magnetic field and ionosphere is sent regularly by 29 Soviet and 90 foreign magnetic observatories to international centers located in the USSR, the USA, Denmark, and Japan.