Descriptive Study of the Ionosphere Charge Variation as a Preamble of Worldwide Earthquakes During 2016

Abstract

This exploratory observational study analyzes the variation of the amount of vertical electrons (vTEC) in the ionosphere, days before to the telluric events with a degree greater than M7.0 during the year 2016. Sixteen events were analyzed with these characteristics. The data was obtained from 55 satellites and 300 GPS receivers. This data was downloaded from the Center for Orbit Determination in Europe (CODE). The measurement of the vTEC is done at a height of 450km, and from these values, ionospheric anomalies are calculated. These disturbances are detected assuming that in a time gap window of 8 days the vTEC data has a normal distribution. The vTEC data used for the analysis consists in the variations out of the ranges considered normal. The data is downloaded with software developed by our laboratory and generates maps of the vTEC present in the ionosphere with a periodicity of two hours, delivering data from 17 days before to 4 days after. The analysis area is a circle with 1000 km radius centered at the epicenter of every earthquake. Afterwards, these areas were analyzed and the vTEC, registering the information in this study. It was found that in 100% of the earthquakes there is a significant and positive variation in the vTEC, a negative variation in the 81.25% of the events. It was also found a vTEC variation 6 days before every telluric event in 100% of the cases. This study is a preliminary analysis that shows us the feasibility to analyze this information to obtain evidence of causality, which is the next step of our study, calculating the risk of telluric events in beforehand that could benefit worldwide population.