The characteristics of continuous gravity changes in Qiongzhong seismic station

Abstract

This paper collected the continuous gravity observation data from Qiongzhong seismic station since 2009. After processing the raw data with sudden jumps，steps and error data，we calculated and analyzed the characteristics of the gravity tide data from Qiongzhong seismic station，the characteristics of the M2 wave tide factor and the spectrum characteristics of the observation data of typical events. The results show that the continuous gravity observation data of Qiongzhong seismic station include not only long-period signals such as solid tide and zero drift，but also high-frequency signals such as earthquakes and typhoons. For the recorded strong earthquakes above 7.0，the frequency of seismic signals is mainly distributed within 0.3 Hz; the disturbance signal caused by the typhoon is mainly distributed in the 0.1—0.4 Hz frequency band; at the same time，the original continuous gravity data of Qiongzhong seismic station and its M2 wave tide factor have no obvious precursory anomalie since 2009.

Keywords

• continuous gravity
• annual variation
• m2 wave tidal factor
• frequency spectrum
• earthquake