大气中一种低频次声波观测研究

分析大气中存在的一种低频次声波。利用宽频带次声测量传感器阵列组成的广域分布网络,对此种次声波进行了近5年不间断的检测。对所测次声信号的观察统计发现,它与自然事件密切相关。对这种信号波形、频谱、时频图及相关性进行分析进一步发现,该波通常以一组或间歇性多组形式出现,频率主要在0.001~0.02 Hz之间、幅度一般可达50~200 Pa。在2008年3月20日新疆于田地震、2008年5月12日四川汶川地震以及2009年10月29日陕甘川三省交界处的地震前,均检测到了大幅值的低频次声波。本文的分析结论对研究大气次声波的多样性及其与自然现象的关系提供了新的参考,对地震信息探测具有一定的实际意义。 

Observation & study of a kind of low-frequency atmospheric infrasonic waves

A kind of low-frequency atmospheric infrasonic waves has been studied. Such infrasonic waves have been observed by a wide-spread sensor network array consisting of broadband infrasound microphones for about 5 years. According to continuous observations and statistic analyses, it could be possible that such kind of infrasound is closely associated with some natural events. The waveforms, spectra, time-frequency charts and correlations among sensors of these infrasonic waves have been analyzed. The results show that these waves occur either in one group or intermittently in several groups with frequencies in a range of 0.001 ～ 0.02 Hz and amplitudes in a range of 50 ～ 200 Pa. Besides, such infrasonic waves were observed previous to several strong earthquakes, such as Yutian earthquake on Mar. 20th 2008, Wenchuan earthquake on May 12th 2008, Shan-Gan-Chuan border earthquake on Oct. 29th 2009, and so on. The results provided in this paper may propel the study of atmospheric infrasonic waves and the correlations with natural events, especially with earthquakes.