CTBT: Science and Technology Conference 2025 - SnT2025

Detection of Large Displacement due to Mw 7.5 28 September 2018 Palu Earthquake using 1 Hz High Rate GNSS Data

P1.2-083

Not scheduled

1h

Zeremoniensaal

E-poster T1.2 The Solid Earth and its Structure P1.2 The Solid Earth and its Structure

Speaker

Thomas Hardy (Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG))

Description

The devastating earthquake followed by the tsunami that occurred in Palu, Indonesia, on 28 September 2018 resulted in the death of more than 4300 people and serious damage to more than 12 000 buildings. Earthquake-induced site displacement is critical information for estimating the magnitude of earthquakes. Compared to a seismometer, which the signal clipping when recording in the near-field of large earthquakes, that may cause underestimated earthquake magnitude determination, the Global Navigation Satellite System (GNSS) records surface displacements directly, making it particularly valuable in the case of large earthquakes. We utilize high-rate 1 Hz GNSS data from the Indonesia Continuously Operating Reference Station (InaCORS) network associated with the Mw7.5 Palu earthquake and generate GNSS dynamic displacement waveforms in three components (east, north, and up) in six GNSS stations that record surface displacement. We calculated peak ground displacement at each GNSS station extracted from three-component GNSS waveform and found that the highest PGD was 292 cm at station PALP, which was located around 78 km from the epicenter. The GNSS dynamic displacement for large earthquakes will be very valuable for rapid estimation of earthquake magnitude that is needed in earthquake and tsunami warning.