Real-time monitoring surface deformation in Indonesia

Real-time monitoring of earthquake-triggered surface deformation is becoming required to characterize the effect of an earthquake, either transient or permanent deformation. Indonesia as a country located in the active deformation region, through Geospatial Information Agency (BIG) has built 397 Real-Time Global Navigation Satellite Systems (RT-GNSS) stations that can be used to observe this phenomenon. The availability of RT-GNSS stations motivates us to provide real-time surface deformation information using the appropriate RT-GNSS processing method. We implement Precise Point Positioning with Regional Augmentation correction (PPP-RA) for stations if there are sufficient regional corrections, and Precise Point Positioning with Ambiguity Resolution (PPP-AR) otherwise. The result shows from Kota Fajar station in Sumatera Island (CKTF), the accuracy can be achieved at ± 1.4 cm, ± 1.8 cm, and ± 6.5 cm for the North, East, and Up components, respectively. we use the earthquake location information produced by Indonesia Tsunami Early Warning System (InaTEWS) operated by the Meteorological, Climatological, and Geophysical Agency (BMKG) to automatically collect the nearby stations from the epicenter. Then, we compute the displacement from each of its stations every second when the earthquake occurred. As a result, we can detect the transient deformation of the Banda Sea earthquake 7.6 Mw at depth of 108 km on January 9, 2023, with a maximum dynamic displacement at the nearest station to the source is 6.6 cm in the North-South direction and 8.7 cm in the East-West direction. This result suggests that this system is effective in displacement detection due to earthquakes.
The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)