[S-SS07] 地震予知・予測+PEGC（仮）

[SSS07-P03] Correlations of earthquake properties with geomagnetic ULF precursor characteristics over multiple events

*Muhammad Khairul Adib Muhammad Yusof¹、Mardina Abdullah^1,2、Nurul Shazana Abdul Hamid^1,3、Suaidi Ahadi⁴、Akimasa Yoshikawa⁵ (1.Space Science Center, Institute of Climate Change, Universiti Kebangsaan Malaysia, Malaysia、2.Department of Electrical, Electronic and Systems Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Malaysia、3.Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Malaysia、4.Department of Geophysics, Indonesian Agency for Meteorology, Climatology and Geophysics, Jakarta, Indonesia、5.International Center for Space Weather Science and Education, Kyushu University, Fukuoka 812-8581)

キーワード：Geomagnetic ULF, Earthquake precursor, Correlational study

We investigated the correlations of earthquake properties with precursor characteristics over multiple events by analyzing geomagnetic field data from 10 observatory stations around the world. Earthquake precursory anomalies were detected by employing the polarization ratio analysis method to process the signal in ultra-low frequency (ULF) ranges (i.e., 0.01 – 0.1 Hz), while the polarization ellipse method was utilized for direction estimation. Earthquakes (n = 34) were studied to characterize their precursors in terms of the frequency band, amplitude, error percentage of direction estimation and lead time. The correlations of these characteristics with earthquake properties (i.e., magnitude, epicentral distance, hypocentral depth and local seismicity index) were then determined. We found that 20 earthquakes were preceded by precursors. Weak correlations were identified when all found precursors were included, but stronger correlations were identified when the study was focused on precursors from a station in Japan. We concluded that some earthquake properties are correlated with several precursor characteristics when the study area is restricted to a specific location.