Time changes of the Wiese vectors in some seismically active regions of the World

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Time changes of transfer functions or so-called Wiese vectors or induction arrows can be caused by various
factors. Great number of researches is devoted to the relation of anomalous time changes of Wiese vectors before
strong earthquakes. Rather interesting results were received for seismically active regions of China and Japan.
Similar researches have been carried out for over than 20 years in a seismically active area of Transcarpathia.
As long as seismic activity in the area of Transcarpathia is very low, we did not detect the correlations of
anomalous time changes of Wiese vectors before the local earthquakes. However some correlations with seismic
activity distribution were noticed: for the earthquakes which epicenters were located in the Transcarpathian
deep fault, anomalous values of induction arrows were observed in the most cases before an earthquake, and for
the earthquakes which epicenters were in the central part of the considered area of Transcarpathian – after an
earthquake. For the analysis of the Wiese vector changes we developed algorithms and programs, which allowed
us to carry out high solubility in the time of calculations of these vectors. For example, for the range of periods
of 5-10 minutes the vectors are calculated for consecutive intervals each 170 minutes. Due to that we got the
patterns of seasonal and diurnal changes of the Wiese vectors. They appear as changing in form and orientation
of the area, which are occupied by the vector tops in the plane of their components (A, B) for all period ranges.
At night this area has a circle form and with the sunrise it begins to extend. Near the midday the figure has
the maximum elongation, and its axis coincides with the meridian. Seasonality appears as the increase of the
length of the figure big axis and its approach to the meridian in summer months. Such seasonal-daily character
of form changes of the figure is, in our opinion, the result of the influence of ionosphere sources on the size and
the direction of induction vectors. In our opinion the developed technique can be useful in investigations of time
changes of the Wiese vectors in the regions with much stronger seismic activity. In particular, we calculated
continuous series of the Wiese vectors using the data from the magnetic observatories (MO) "Irkutsk" (Russia),
"Kakioka", "Kanoya", "Memambetsu" (Japan). In August 2008 near the MO "Irkutsk" (60 km) an earthquake
with М = 6.2 occurred. Using the continuous magnetic variation measurements from 1998 to 2008 of the
"Irkutsk" station we calculated the Wiese vectors. From the results we can conclude that throughout three
months before the earthquake a strong bay-like anomaly in the component A of the Wiese vector was observed.
Its amplitude exceeded the average level of this component approximately by 30 For Japan MO Wiese vectors
are calculated from 1991 to 2008. Their time changes were compared with the earthquakes occurred at the
distance up to 100 km from every MO with magnitudes over 5.5. The most evident are the time correlations of
Wiese vector anomalous changes before the earthquakes in MO "Kakioka" region. Here even some dependencies
of the character of Wiese vector anomalous changes on earthquake hypocentres depth, epicenral distance and
magnitudes are noticeable. Seasonal changes of Wiese vectors are also clearly detectable at every of Japan MO.
The results presented in this paper rely on the data collected at magnetic observatories. We thank the National
Institutes that supports them and INTERMAGNET for promoting high standards of magnetic observatory
practice. (www.intermagnet.org).