Investigation of ULF magnetic anomaly during Izu earthquake swarm and Miyakejima volcano eruption at summer 2000, Japan

Results of the ULF electromagnetic emission during earthquake (EQ) swarm and Izu-Miyake volcano eruption at summer period of 2000 are presented and analyzed. Analysis of the obtained data has been performed in 3 main directions: traditional statistical analysis i.e. analysis of time dynamics of spectral density, polarization ratios and their derivatives, principal component analysis and fractal analysis. Statistical characteristics were studied at different frequency sub-bands in a frequency range 10
^-3
-0.3 Hz. The mentioned methods of data processing are described and obtained results are illustrated and discussed. Some peculiarities of obtained results such as rise of the second principal component and rise of fractal index can be interpreted as a possible short-time precursors