THE EFFECT OF THE AEGEAN SEA EARTHQUAKE, OCCURRED ON OCTOBER 30, 2020, ON TUSAGA STATIONS

Abstract

GNSS is used to determine the point positions on the earth with high accuracy. The accuracy that can be achieved with GNSS depends on the satellite system, processing software, logging interval, observation time, etc. varies depending on the effects. In the study, the impact of the Aegean Sea Earthquake that occurred on November 30, 2020, on TUSAGA was investigated. For this purpose, 7 TUSAGA stations located in the earthquake-affected area were selected. The 24-hour RINEX data for these stations were obtained both 15 days before and after the earthquake. The 24-hour RINEX data of 7 TUSAGA were processed using the GAMIT/GLOBK, based on 14 IGS stations. Furthermore, the evaluations were repeated by dividing the 24-hour RINEX data into 2, 4, and 12-hour intervals. In the evaluation, the GPS+GLONASS+Galileo (MIX) satellite configuration was utilized. The daily solutions obtained to reveal the effect of the earthquake are divided into two parts as before/after the earthquake. For each of TUSAGA stations, pre- and post-earthquake coordinates and RMSE were calculated. With statistical tests, whether the changes in the points are significant or not, the amount and direction of the changes were determined with 95% statistical confidence. As a result, it was concluded that the changes before/after the earthquake were mostly in the MNTS, which is the closest to the earthquake base, the changes in the points generally decrease as you move away from the earthquake center, and the evaluation before/after the earthquake can be made more healthy as the observation time increases. In addition, 30-day coordinates were examined through time series, and only the graph of the change in MNTS was given since it was the closest station to the epicenter of the earthquake.