Sagaing Fault slip and deformation in Myanmar observed by continuous GPS measurements

The Sagaing Fault is a major tectonic structure between the Indian Plate and Sunda Plate. The fault measures 1200 km along north–south and cuts through the centre of Myanmar. Many urban areas lie along the fault. As a result, Myanmar has established a continuous Global Positioning System (cGPS) network across the Sagaing Fault since 2011. The cGPS network consists of eight cGPS stations that form two transects across the fault. The data analysis covers a period of four years from 2011 to 2014. GAMIT, GLOBK, and TRACK software suite packages are used for GPS data processing and analysis. This study consists of two main objectives. The first objective is to analyse the Myanmar cGPS network observations in order to measure the moving rate and direction of movement for each cGPS station using GAMIT/GLOBK software packages. The second objective is to investigate the co-seismic moving rate associated with the earthquake event using TRACK kinematic positioning program. The analysis results indicate that the east side of the Sagaing Fault moves southeastward at the average rate of approximately 32–40 mm/a, whereas the west side of the fault moves northeastward at the rate of about 31–35 mm/a. For co-seismic analysis, two cGPS stations are analysed in connection with the 2012 M6.8 Thabeikkyin earthquake. These stations are located 50–60 km away from the epicentre. The GPS data analysis clearly showed that the station at the east side of the Sagaing Fault immediately moved south by 15.0 cm, whereas the station at the west side of the fault moved north by 3.0 cm. In conclusion, this study demonstrates that the Sagaing Fault's tectonic activities can be monitored by cGPS observations using geodetic processing techniques. We believe that such investigation brings contribution to better understand of the tectonic activities in Myanmar and South East Asia.