Abstract Earthquake (EQ) related variations in the ionosphere may provide some insights to understand the seismo ionospheric coupling and to mitigate the damages of seismic hazards. In this paper, the electromagnetic variations in the ionosphere associated with November 14, 2007, M7.7 Chile EQ are investigated in electron density and electron temperature measurements from ISL (Langmuir Probe) of DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) satellite and TEC (total electron content) estimated from GPS (Global Positioning System). The investigation of temporal and spatial measurements suggests anomalies which are observed within 10 days before the future EQ (i.e. 9 days before on November 5, 2007). The temporal values of daytime DEMETER and diurnal TEC on November 5, 2007 imply abrupt anomalies that are considered to be the fragments of the plasma intensification process in the Southern Hemisphere activated by the rock compression in the quake region. Similarly, spatial maps of TEC and DEMETER (electron density and electron temperature) showed the anomalous configuration of the temporal analysis that may induce by the epicenter. In addition to spatial and temporal analysis, the Index number for the northern and southern sectors of the EQ preparation zone around the epicenter along latitude confirmed the anomalous values of electron density and electron temperature of the DEMETER satellite. Similarly, the comparison of electron density and electron temperature at the epicenter latitude and its conjugate reveals anomalous enhancement over the seismogenic zone on November 5, 2007 (9 days before) prior to the event.

中文翻译：

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GPS TEC和DEMETER在智利M7.7地震前的地震电离层异常

摘要 电离层中地震（EQ）相关的变化可能为理解地震电离层耦合和减轻地震灾害的损害提供一些见解。在本文中，在来自 DEMETER（地震区传输的电磁辐射检测）的 ISL（朗缪尔探测器）的电子密度和电子温度测量中，研究了与 2007 年 11 月 14 日 M7.7 智利 EQ 相关的电离层中的电磁变化) 卫星和 TEC（总电子含量）从 GPS（全球定位系统）估计。对时间和空间测量的调查表明，在未来 EQ 之前 10 天内（即 2007 年 11 月 5 日之前的 9 天）内观察到异常。11月5日白天DEMETER和昼夜TEC的时间值，2007 年意味着突然异常，被认为是南半球由地震区岩石压缩激活的等离子体增强过程的碎片。同样，TEC 和 DEMETER 的空间图（电子密度和电子温度）显示了可能由震中引起的时间分析的异常配置。除时空分析外，震中周围EQ准备区南北段的Index数证实了DEMETER卫星电子密度和电子温度的异常值。同样，震中纬度及其共轭处的电子密度和电子温度的比较揭示了11月5日在发震带上的异常增强，