Analysis of Abnormal Infrasound Signals in Different Regions

The characteristics of the abnormal infrasound signals before the M ≥7.0 earthquakes from2002 to 2014 occurred in Vanuatu were studied in this paper by using infrasonic observation method.It is found that the waveforms is similar,and these waves occur in one groups with frequencies in a range of0.001-0.005 Hz.Moreover,the characteristics of the abnormal infrasound signals of the M7.1 April14,2010 Yushu Earthquake,the M7.0 April 20,2013 Yaan Earthquake,the M6.6 July 22,2013 Dingxi Earthquake and the M7.3 February 12,2013 Yutian Earthquake were analyzed.It is found that the abnormal infrasound signals have different waveforms in different regions.This research is contributed to study the relationship between the abnormal infrasound signals and the source of earthquakes,and it also has the certain practical significance in prediction of seismic source.