ANNUAL VARIATIONS OF MAGNETIC-VARIATION PARAMETERS ACCORDING TO THE DATA FROM MAGADAN AND PARATUNKA OBSERVATORIES IN KAMCHATKA

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Variations in the geomagnetic field contain data on the electrical conductivity of rocks that can be obtained
using transfer magnetic variation parameters represented by a magnetic tipper and magnetic tensor. The mag-
netic tipper shows the relationship between variations in vertical component and horizontal component of the
geomagnetic field at one site. The magnetic tensor shows a link between horizontal components of the geomag-
netic field variations during simultaneous monitoring at two different sites. The magnetic tipper and tensor
have been investigated at Magadan and Paratunka observatories over the period of 2007-2008 using data from
simultaneous monitoring of the geomagnetic field variations at intermittency up to 1 s. The analysis revealed
that the magnetic-variation parameters are steadily determined in the interval not less than 5 days. Then the
coherency between vertical and horizontal components must be at least 0.8. A new program was specially de-
veloped to calculate time series of the magnetic tipper and tensor within the periods from 300 to 10000 s. Real
parts are associated with active electric currents while imaginary parts relate to reactive currents. The value of
imaginary parts is determined by induction in conductive beds. At the Paratunka observatory the imaginary
parts are steadily determined within 1000 s, while for those at the Magadan observatory the interval is 300 s.
At these periods the modules behavior of imaginary parts shows clear annual variations. These periods on the
MTS curves are confined to the minimum related to the crust conductive layers. Thus, the annual variations
in modules of imaginary inductive parts specify conductivity variations in the crust conductive layer in which
concentration of electric current is caused by induction. We suppose that concentration of currents provides
stable values and well defined annual variations in imaginary inductive parts over the periods of 1000 s and
300 s. Note that annual variations are less observed in other periods. Annual variations in conductivity may
occur at a greater or less degree in various lithosphere layers. We suggest that the annual variations in the
lithosphere conductivity may be related to geodynamic processes occurring on an annual cycle basis due to the
rate of the Earth illumination during its annual trip around the Sun. Possibly these processes lead to changes
in depth and width of lithosphere faults, to the level of their saturation with hydrothermal solutions and degree
of mineralization displayed by variations in the lithosphere conductivity.