【作者】 马新欣；

【导师】 李录明；

【作者基本信息】 成都理工大学 ， 地球探测与信息技术， 2009， 硕士

【摘要】 目前地震电离层扰动的物理解释众说纷纭,孕震过程与电离层异常的关系并不完全清楚,本文在前人研究成果的基础上,利用中国大陆GPS(Globe Positioning System)观测站数据,根据电离层单层模型,针对2001~2008年发生在中国大陆地区的27个震例,分析了27个震例在地震期间电子含量的时间序列变化、GPS卫星与观测站路径穿刺点位置电子含量变化,预测了震中区域。通过GPS数据解算TEC(Total Electron Content)的结果表明,利用本文的方法计算TEC精度可以满足电离层扰动特征的研究,论文研究成果主要为以下五个方面:1)完成2001~2008年发生在中国大陆地区的27个震例的分析工作,研究其中20个震例结果表明有13个震例TEC值出现负异常现象,主要表现在震前1~5天;3个震例在地震发生期间电离层表现为正异常现象,集中在地震发生当天、震后一天;4个震例在地震发生前7天到地震发生后7天电离层没有出现明显的扰动现象,地震期间TEC变化平缓。2)出现负异常的13个震例中8个震例显示GPS观测站距离震中越近,观测站垂直上空电子含量变化越明显,距离震中700km以外的观测站上空电子含量在地震活动前后几天没有出现明显异常现象,TEC变化基本在0.5个TECU以内。大部分震例表明地震并没有引起距离震中700km以外观测站上空电子含量变化。3)大部分震例中地震没有引起GPS卫星与观测站路径穿刺点位置电子含量在短时间内的扰动。部分震例体现了磁场与电离层时空异常特征有很好一致性。4)地震期间电离层出现负异常扰动的天数集中在震前第5天、第4天、第2天、第1天,负异常出现在震前第5天、第2天的概率在85%以上,正异常集中出现在地震当天、震后第1天。本文研究中取得的一些认识表明,利用地基GPS观测数据,可以清楚地获取地震电离层异常扰动的特征,研究认为利用GPS连续观测数据研究与地震有关的电离层前兆是可能的。更多还原

【Abstract】 Now the opinions vary on mechanism of seism-ionospheric disturbances and its physical explanation. It is not clear to identify the possible relationship between earthquake and ionospheric anomalies. Based on the achievement of predecessor, this paper researches that based on the single layer ionosphere model, we have processed the observation data at some GPS observation stations and obtained total electron content(TEC)time series of the ionosphere, TEC for location of the sub-ionospheric point along observation and GPS satellite to study the epcentre region. We have studied the TEC anomalies of 27 Ms≥6.0 earthquakes which occurred in Chinese mainland during 2001-2008.Through Calculating TEC with GPS data, results show correctness and validity of this method. The main achievements of research include five aspects as follow.1)Results show that the TEC values above observation stations have negative anomalies of 13 times in 20earthquakes. TEC anomalies mainly appeared 1 day to 5 days before earthquakes; The TEC values above observation stations have positive anomalies of 3 times in 20 earthquakes. TEC anomalies mainly appeared 1 day after earthquakes、the day of earthquake occurrence; The TEC values above observation stations have no obvious anomaliese before and after earthquakes of 4 times in 20 earthquakes .2)The TEC have negative anomalies of 8 times in 13 earthquakes show the closer the station is to the epicenter, the larger the TEC anomalies becomes. The TEC values above GPS continuous observation stations 700km away from the epicenter have no obvious anomaliese before and after earthquakes, and TEC variation is within 0.5 TECU.3)Most of earthquake cases show that, TEC have no obvious anomaliese during earthquake, for location of the sub-ionospheric point along observation and GPS satellite. The result shows that the temporal-spatial characteristics of short-imminent anomalies of ionosphere and geomagnetic field are consistent.4)TEC negative anomalies mainly appeared 5 day、4 day、2 day、the day of earthquake occurrence, 5 day、2 day before earthquakes, and its probability is about 89%; TEC positive anomalies mainly appeared the day of earthquake occurrence、1 day after earthquakes.This paper results show that Characteristics of seism-ionospheric disturbances can be obtained with GPS observation data. It is possible to identify ionospheric anomalies before earthquakes from continuous GPS observation data.更多还原