Historical earthquakes, tsunamis and real-time earthquake monitoring for tsunami advisory in the South China Sea region

Abstract

The South China Sea Tsunami Advisory Center (SCSTAC) established by China, under the aegis of UNESCO's Intergovernmental Oceanographic Commission (UNESCO/IOC), had inaugurated commencing its full operation on November 5, 2019. This center is operating 24 × 7 h and round-the-clock shift to monitor tsunami hazard that pose a serious threat to countries which bordering the South China Sea (SCS) region. Prior to the official operation, SCSTAC had taken action for the last 10 years in upgrading their technology capability which are real-time earthquake monitoring and the processing system that is crucial to be able providing the international standard of tsunami warning services in the SCS and its adjacent areas. This paper briefly reviewed on the initiation steps and its developments of the South China Sea region Tsunami Warning and Mitigation Systems, tectonic setting as well as the characteristics of historical earthquakes and tsunamis in the region. In addition, we highlighted the structure and basic functions of the earthquake monitoring and processing system, earthquake location, source mechanism solution and finite fault model inversion using the real-time seismic waveform data from regional and global seismographic networks that will result in the rapid source parameters estimation for a larger earthquake in tsunami warning. Numerous simulations and hands-on events have shown that the preliminary earthquake parameters could be determined less than 8 min after earthquake. The W phase method is used and be able to produce rapid and reliable estimation of the moment magnitude and source mechanism for larger events within 10–15 min from earthquake origin time. A finite fault model can be acquired just after the earthquake event via computing teleseismic body-wave inversion program. The earthquake monitoring and processing system provide accurate and reliable information in contributing to tsunami warning services, thus promoting the development of tsunami warning technologies, which enhancing the tsunami warning capability and tsunami emergency responses. These high-end technology can be used in facilitating others such as marine disaster prevention, mitigation and its risk reduction.