【摘要】 2010年4月14日07时49分,青海省玉树县发生了MS7.3级地震.为了了解玉树地震前后玉树地震台的噪声水平有没有变化,我们对玉树地震台记录的噪声进行了两方面的研究,即分别计算噪声均方根值和噪声功率谱.研究表明,玉树台的高频噪声功率谱在2009年比2008年要高3～8dB.震前一个月左右,高频噪声开始有升高现象,震前半个月左右,高频噪声的功率谱能量显著升高,地震后,高频噪声经过继续急剧升高、开始慢慢回落、到回落到噪声模型水平三个阶段.噪声回落到2008年的噪声水平,明显低于地震前1个月的噪声水平,所以我们认为震前高频噪声升高与玉树地震有关,属于噪声异常.更多还原

【Abstract】 A earthquake occurred on Apr.14,2010 in Yushu county,Gansu Province in North China,the magnitude is MS 7.3.We researched the noise of Yushu station around the hypocenter of Yushu earthquake to see the variations of noise before and after the Yushu earthquake.We used two methods to research the noises,one is to research the RMS of the noises in several frequency bands, the other method is to research the noise spectrum during the one month before and after the Yushu earthquake.The research results told us that the noise of Yushu station had a higher noise level in 2009 than the level in 2008 in high frequency bands.The high frequency noise spectrum has minor increase relative to the noise model one month before Yushu Earthquake,has obvious increase half month before Yushu Earthquake,and has gradual decrease after a sharp increase after the earthquake.At last,the high frequency noise decrease gradually to a 2009 and even a 2008 model level,which lower than the noise level one month before Yushu Earthquake,seem to donate the fact that the high frequency noise increase before Yushu Earthquake have relationship with Yushu Earthquake,which is called the noise anomaly.更多还原