Articles | Volume 7, issue 4
22 Aug 2007
22 Aug 2007

Application of different signal analysis methods to the ULF data for the 1993 Guam earthquake

Y. Ida, M. Hayakawa, and S. Timashev

Abstract. Two different analysis methods; (1) mono-fractal analysis (based on Higuchi method) and (2) flicker noise spectroscopy, have been applied to the same ULF (frequency less than 10 Hz) electromagnetic data observed at Guam during 3 years including the 1993 August Guam earthquake. The results by these two methods are found to be very consistent with each other; that is, some precursory effects seem to start about 3 months before the earthquake. This gives us a strong support to the self-organizing critical process before the Guam earthquake.