secular variations in Ukraine on the base of RS network
Maksymchuk, V. (1), Orlyuk, M.
Branch of S.I.Subbotin's Geophysical Institute,Ukrainian academy of
Sci., Lviv, Uktaine; (2) S.I.Subbotin's Geophysical Institute,
Ukrainian academy of Sci., Kyiv, Ukraine
observations on the RS network let us obtain information about
absolute values of magnetic field components, which are the base for
normal magnetic field maps plotting. But repeat observations on the RS
network give a possibility to obtain magnetic field secular variations
(SV) data and information about their spatial structure. Considering
size of the investigating area (18 degrees in E-W direction and 8
degrees in N-S direction) the problem of normal geomagnetic field and
its SV mapping is very actual for Ukraine.
In 2018 SV network in Ukraine consists from 78 points (near 1 SV
point in 8,000 sq.km). More, in Ukraine are based 3 magnetic
observatories: Kyiv, Lviv, Odesa. Recent RS network was founded during
2003-2004 yrs. And first cycle of observations was fulfilled. Repeat
observations were done during 2010-2011 yrs. The results were the base
for maps of secular variations, X, Y, Z, F, D components for 2010-2005
years. Especially complex SV spatial structure in all magnetic field
components was stated.
Few anomalous zones of F SV morphology in Ukraine are defined.
Minimum values of SV are characteristic in Transcarpathians (28 nT/per
year), Volyno-Podillya (30 nT/per year), Crimea Peninsula (30 nT/per
year). Central and Eastern parts of Ukraine are characterized by
mosaic SV structure of F field with some isometric anomalies, proved
only by one SV point.
Comparison of SV spatial structure, based on the SV points data and
IGRF model shows essential differences. Deviation from IGRF model for
F, Z components were defined in active seismic regions of Carpathians
and Crimea (-2-3 nT/per year), for Volyno-Podillya and Donbass (2-3
nT/per year). The same time close correlation of SV anomalies
structure with anomalous magnetic field can be observed. It testifies
Earth’s lithospheric sources impact in magnetic field SV.
The next repeatable geomagnetic observations cycle on the Ukrainian
SV network is planned in 2019-2020 yrs.