# Study of Relationships Between Local Seismic Activity and Magnetotelluric Field Changes

**Author(s):**Rozłuski C.

**Volume:**326

**Series:**C-77

The goal was to find possible confirmation of the fact that in the magnetotelluric recordings in seismic zones there are signals associated with seismic activity in the region. This is claimed by many authors for the purpose of earthquake prediction or in order to find earthquake precursors. Superpositions of transformation functions from the physical observables space into the hypothetical model space, where correlation can be observed, have been defined. Unfortunately, these superpositions and functions are irreversible, limiting the possibility for earthquake prediction. The single scalar function of magnetotelluric field, calculated in frequency domain, has been introduced with simple physical interpretation related to energy transmission through the Earth's surface. For the seismic events set of observables, two different, discrete in time-space, transformations have been introduced, arising from two models: for Greek and Japanese data. The transformations for magnetotelluric and seismic observables have a common smoothing algorithm, a case of weighted least square method. This is essentially a sophisticated noise-reduction algorithm, radically reducing the number of model free parameters and improving the signal-to-noise ratio. For the purpose of model testing the magnetotelluric data from Ioannina, Greece, stations has been analyzed in the frequency domain.

MONOGRAPHIC VOLUME

CONTENTS

Abstract, ...3

1. Variety of phenomena related to earthquakes, ...4

2. Brief report on electromagnetic phenomena observed before earthquakes, ...5

3. Magnetotelluric induction and the premonitory phenomena, ...8

4. Transformations of real observables for magnetotelluric field and seismic events, ...10

5. The experimental data, ...13

6. Data analysis, ...22

7. Generation mechanisms of electromagnetic signals in earthquake source zone, ...36

8. Conclusions, ...41