ANOMALY ANALYSIS OF VP TYPE BROAD FREQUENCY BAND
TILTMETER AT LINFEN SEISMOSTATION BEFORE SHANXI
HEJIN EARTHQUAKE
1)Linfen Central Seismostation, Earthquake Administration of Shanxi Province, Linfen 041000
2)Taiyuan State Observatory of Continental Rift Valley Dynamics, Taiyuan 030025
3)Xiaxian Central Seismostation, Earthquake Administration of Shanxi Province, Xiaxian 044400
4) Key Laboratory of Earthquake Geodesy, Institute of Seismology, CEA, Wuhan 430071
Abstract On the basis of the observation data of VP type broad frequency band tiltmeter in Linfen seimmostation, the overall elaborate change process of seismogenic system before Hejin M4.8 earthquake was recorded: 1)one year before the earthquake, the curve had the performance of α、β、γ stage anomaly form;2) The slow earthquakes were recorded from 35 days before and 7 days after the earthquake; 3) Frequency spectrum analysis showed: one month before the earthquake, the amplitude magnified obviously in frequency range of 0.1, 0.3 and 0.5 Hz, in the month of the earthquake occurring, the amplitude strengthened in frequency range of 0.1-0.5 Hz; 4) Two months before the earthquake, the loadunload response ratio appeared the high and low level fluctuation, and the loadunload response ratio figure was increscent with arrival of the earthquake.
Li Yan,Gao Zhenqiang,Zhang Yanghui et al. ANOMALY ANALYSIS OF VP TYPE BROAD FREQUENCY BAND
TILTMETER AT LINFEN SEISMOSTATION BEFORE SHANXI
HEJIN EARTHQUAKE[J]. jgg, 2013, 33(Supp.2): 24-27.
Li Yan,Gao Zhenqiang,Zhang Yanghui et al. ANOMALY ANALYSIS OF VP TYPE BROAD FREQUENCY BAND
TILTMETER AT LINFEN SEISMOSTATION BEFORE SHANXI
HEJIN EARTHQUAKE[J]. jgg, 2013, 33(Supp.2): 24-27.
