Abstract In this work, a relationship between ionospheric TEC anomalies and different earthquake magnitude groups before the main shocks was investigated. For this purpose, 2942 global earthquakes with Mw≥6 from 2000 to 2019 and possible ionospheric TEC anomalies that occurred before earthquakes were examined by considering 13 different index values of space weather conditions (geomagnetic storm indices and solar activity indices). Anomalies of ionospheric TEC changes were defined for 15-days before and 4-days after the earthquakes by using 15-days moving median method with the length of 15 days. Earthquakes were first grouped according to their magnitudes, and then negative and positive TEC anomalies in quiet days before the earthquakes were detected. These anomalies were observed as ∼5–13, ∼5-10, ∼5-15, ∼3-13, ∼7-15, ∼1 and ∼5-8 days ago for the earthquakes of 6.0 ≤ Mw

中文翻译：

---

2000-2019年全球地震电离层TEC异常与地震震级（Mw≥6.0）相关的分析

摘要 在这项工作中，研究了主震前电离层TEC异常与不同地震震级组之间的关系。为此，通过考虑 13 个不同的空间天气条件指数值（地磁暴指数和太阳活动指数），研究了 2000 年至 2019 年发生的 2942 次 Mw≥6 的全球地震和地震前可能发生的电离层 TEC 异常。采用15天移动中位数法定义震前15天和震后4天的电离层TEC变化异常，长度为15天。首先根据震级对地震进行分组，然后在检测到地震前的平静日子里对 TEC 的负异常和正异常进行分组。这些异常被观察到为~5-13、~5-10、~5-15、~3-13、~7-15、