9:15 AM - 9:30 AM
[SSS05-02] Earthquake monitoring in Indonesia: Evaluation of the earthquake catalog, magnitudes, and sensor misorientation from BMKG nationwide seismographic network
Keywords:seismic network, earthquake monitoring, earthquake catalog, magnitude, seismic sensor
Indonesia is a seismically active region with a complex tectonic setting. To monitor earthquakes in the Indonesia region, the Indonesian Agency BMKG (Badan Meteorologi, Klimatologi, dan Geofisika) has been operating a nationwide monitoring system using the permanent digital seismometer network of Indonesia (network code IA). However, the earthquake catalog/bulletin resulting from this nationwide monitoring has not yet been evaluated and discussed. In this study, we assessed a decade of seismic activity in Indonesia with a focus on cataloged earthquakes from 2008 to 2024 (17 years), and we noted that since 2019, the network has significantly improved by adding more seismic stations. We analyzed the earthquake parameters, mainly the magnitudes, and compared them with their various magnitude types and moment magnitude by the Global Centroid-Moment-Tensor (GCMT) catalog. A unified earthquake catalog with homogeneous (local) magnitudes is obtained. We evaluated ~100K earthquakes during this period with the data complete at the local magnitude of 3.5 based on their frequency-magnitude distribution (FMD) analysis. We then computed seismicity rates of M>3.5 for different regions and tectonic regimes in Indonesia. We also discuss the seismicity 2020-2024 after the significant increase of seismic stations in the IA network. In addition, we estimated the sensor misorientation of these seismic stations. Finally, we discussed seismicity evolution and its seismotectonic implications. Our study is necessary for further seismic hazard assessment in Indonesia.