Detection and assessment of geodynamic effects on a portion of Brazilian GNSS stations

Abstract

This work presents a methodology for detecting possible geodynamic effects using GNSS data, SIRGAS, Geological, and Geophysical velocity models. GNSS observations were processed to obtain the variation for the vertical (up) and horizontal coordinates. The VEMOS2009 and 2015 velocity models served as a comparative basis to verify the results obtained with GNSS processing. From the set of velocity vectors of stations belonging to the Brazilian Network for Continuous Monitoring of the GNSS (RBMC) obtained from NNR-NUVEL-1A, estimated the defining elements of the movement of the SOAM plate. Then, it performed some analyses and comparisons with the SOAM plate rotation vectors obtained by the APKIM2008 model. The studies conducted were based on continuous observations, from 2007 to 2016, on a portion of GNSS stations belonging to RBMC (SIRGAS-CON stations). The results considering the SIRGAS velocity models showed that after the earthquake in Chile, in some regions of Brazil, there were geodynamic effects. Comparison to the geological and geophysical models, it was observed that the velocity field defined in GNSS processing was able to portray reality, as well a s case study, which was considered the Imbituba station.