Investigation of the effect of 30 October 2020 Aegean Sea earthquake on crust deformation with TUSAGA-active data

The TUSAGA-Active (Turkish National Continuous Operating Reference System) is available for commercial and academic studies with 181 fixed GNSS (Global Navigational Satellite Systems) stations. Its capability to provide high-accuracy data facilitate to monitor deformations resulting from crustal movements. On October 30, 2020, an earthquake with a magnitude of ML = 6.6 (MW = 6.9) struck the Aegean Sea at 14.51 local time. The aim of the study is that TUSAGA-Active stations located within the earthquake-affected area are thoroughly examined to detect any crustal deformations caused by this seismic event. As part of this analysis, deformation directions and magnitudes were determined for stations AYD1, CESM, DIDI, IZMI, KIKA, and SALH. RINEX data from 15 days before the earthquake date and 11 days after were processed using CSRS-PPP (Canadian Spatial Reference System Precise Point Positioning Service) and OPUS (Online Positioning User Service), which are internet-based GNSS services. The results of this analysis revealed that the CESM station experienced the most significant displacement, averaging 57.39 mm in the north direction according to the CSRS-PPP service. Similar results were obtained from the OPUS service data.