普洱地震前电离层电子密度扰动变化研究

Study on ionospheric Ne disturbances before 2007 Pu'er,Yunnan of China,earthquake

挑选普洱地震前邻近地震震中的3条轨道的电子密度(Ne)数据,分析其1年内的所有重访轨道,并提取了这次地震前的Ne前兆异常.结果表明:①夜间电离层Ne存在明显的季节变化,4个季节呈现了各自不同的变化形态;②Ne的主要变化形态有3种,即单峰、马鞍和平缓状,这些形态在各个季节都可能出现,但每个季节有相对集中的形态;③Ne空间图象在震前30天内在震中区附近形成高值,异常信息在空间和时间上都与地震分布有很好的相关性,反映空间出现的异常信息确与本次地震有关;④Ne重访轨道曲线形态有一定的相似性,可以为识别判定地震异常提供背景信息.

Selecting three half orbits near the epicenter of 2007 Ms6.4 Pu＇ er earthquake, we analyzed the No data recorded on their revisited orbit during a year before this earthquake, and extracted Ne precursors. The results show that： ①There are significant seasonal variations of ionospheric No in night time, with different varying style in the four seasons;②There are three main types of Ne variation： single-peak, saddle-shaped, even-shaped, all of which may occur in four seasons, but each season has its relatively typical variation style;③Spatial images of No showed high values near the epicenter for 30 days before the earthquake, and there is a good correlation between anomaly and distribution of earthquakes in space and time, implying that these spatial anomalies were indeed associated with the earthquake;④The Ne variation curves show a certain similarity among revisited orbit. This similarity may provide background information for distinguishing and identifying seismic anomaly.