An Z.-H.,Lanzhou Base of Institute of Earthquake Sciecne |
An Z.-H.,State Geophysics Observatory in Lanzhou |
An Z.-H.,Lanzhou Institute of Seismology |
Du X.-B.,Lanzhou Base of Institute of Earthquake Sciecne |
And 20 more authors.
Earthquake | Year: 2015
In this paper, Hilbert-Huang Transformation method is introduced to deal with geo-electric field data observed by the stations around the epicenter of 2013 Lushan Ms7.0 earthquake. These stations include the stations of Gansu Pingliang, Sichuan Chengdu and Yunnan Yuanmou. We compare the results of the three geo-electric field stations between the normal time with the eve of the Lushan Ms7.0 earthquake, the results of Chengdu geo-electric field station about the Lushan Ms7.0 and Wenchuan Ms8.0 earthquakes are also analyzed. We conclude that: (1) HHT method is effective for the data analysis observed by the geo-electric field station, the time-frequency spectrum may be simple and intuitive; (2) About 1~2 months before the Lushan Ms7.0 earthquake, the energy of geo-electric field enhanced, with period range of approximately 90~1400 hours, the minimum amplitude of energy variation is about 3 orders of magnitude, the largest ranges up to about 6 orders; (3) The credibility of results obtained are greatly enhanced through comparison obtained from the three geo-electric field stations, and analogy obtained from the Chengdu geo-electric field station. In the discussion section of results, we discussed the situation of seismic electromagnetic signals based on the experimental and numerical simulation method in the domestic and abroad in recent years, these results obtained by them can provide theoretical support to our results in this paper. ©, Science Press. All right reserved.