Performance test of pilot Earthquake Early Warning system in western Java, Indonesia

This study assesses the performance of a pilot Earthquake Early Warning (EEW) system set up in Java's western region in Indonesia. The Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG) developed the pilot EEW system based on the Earthworm Platform, in response to local seismic activity. The system aims to deliver early alerts for seismic occurrences by leveraging the seismic network set up by BMKG. In this paper, we proposed EEW suited to Indonesia, using T p d to identify events and T n o w to estimate earthquake parameters and integrated these into the Earthworm Platform using accelerograph data from the BMKG network. The pilot EEW system was tested on real-time scenarios in 27 events in the western part of Java from October 2022 to May 2023. Based on real-time testing, the systems proved to be quick (6 s after origin time in the 2022 Cianjur earthquake) and accurate in providing earthquake parameters, such as origin time, hypocenter, and magnitude compared to the BMKG catalog (Note: Epicenter errors are less than 30 km, with more than half of the errors falling under 10 km; the majority of events have origin times calculated within a margin of about 2 s, and a magnitude error between 0.3 and 0.6). These results offer valuable insights into the operational capabilities of the pilot EEW system in western Java and its capacity to issue accurate early earthquake warnings in Indonesia. • Evaluation of the effectiveness of a pilot EEW system using real-time accelerograph data from BMKG stations. • EEWS results showed accurate earthquake data as Origin Time, Hypocenter, and magnitude in western Java Island. • The EEWS which used Tpd and Tnow techniques showed improvement from initial alert to final result