On morphological signs in the structure of geomagnetic variations on the eve and at the moment of earthquake in the Crimea-Black Sea and the Carpathian regions
© F.I. Sedova, T.A. Mozgovay, V.G. Bakhmutov, 2001
The observations made at the geophysical station "Yastrebovka" (Crimean Peninsula) for
1990-1994 were used to describe morphological effects in the geomagnetic field
variation structure due to weak shocks in the Ukrainian Carpathians and in the
Crimea-Black Sea seismic zone and strong deep-focus earthquakes in the Vrancea
region. The shocks concern mainly the low values of the H-component of the
field. The shock magnitude is related to the gradients (differences) in the
geomagnetic field. The authors show a linear relation between the ratios of
extreme values of H-component at the moment shock (H2) and in
the previous period (H1) depending on the energy class of the earthquake.
A linear relation of the period of PcS-pulsations from the focal depth especially
significant for the Vrancea region has been established.
The role of the observation points location relative to the earthquake
focus in studies of geomagnetic effects is noted.