Long-Short Rupture Boundary of Coseismic Displacement Estimation Based on 30-Seconds GNSS Observation

Indonesia is located at the Pacific Ring of Fire and the meeting place of the world's four tectonic plates, which makes Indonesia to have a high tectonic activity and to be prone to earthquakes. Currently, early earthquake detection service in Indonesia is based on seismometers network. However, seismometer instruments that observe seismic waveforms might become saturated, and as such may lead to incorrect earthquake magnitude detection at an early stage. Therefore, a new approach is needed to detect earthquake coseismic information. Global Navigation Satellite System (GNSS) is a good instrument to measure the surface displacement due to an earthquake. However, previous studies in Indonesia still predominantly used daily solution data. To carry out early detection, it is not possible to use daily solutions. Therefore it is needed to use the data with a higher frequency solution than the daily solution. In this study, we used 30-second sampling rate data available from Indonesian Continuously Operating Reference Station (Ina-CORS) and Sumatran GPS Array (SuGAr). We will see how the 30-second GNSS data responds to earthquakes to estimate the value of coseismic displacement compared to daily solution data. The estimated value of this coseismic displacement can be used for earthquake early detection.