Tsunami hazard and early warning system in South China Sea
Introduction
Tsunami is one of the most devastating natural coastal disasters. Most of large tsunamis are generated by submarine earthquakes occurring in subduction zones. Tsunamis can also be triggered by volcano eruptions and large landslides. Although the skill for predicting earthquake is still in its infancy, a tsunami warning system is still possible for a distant tsunami if the tsunami can be detected in the open-ocean. Information on the arrival time and the height of leading tsunami wave in areas far away from the source region can be predicted with some confidence (e.g., Wei et al., 2003).
Such a tsunami warning system is now operational in the Pacific Ocean and has proven its effectiveness and validity for several recent tsunami events. If a similar early warning system had been available in the Indian Ocean, the 2004 Indian Ocean tsunami would have caused much less damage in property and loss in human lives in Sri Lanka, India, Maldives and other coastal regions.
In the South China Sea (SCS) region, the Manila subduction zone has been identified as a high hazardous tsunamigenic earthquake source region. No earthquake larger than Mw = 7.6 has been recorded in the past 100 years in this region, suggesting a high probability for larger earthquakes in the future. And most alarmingly, there is no operational tsunami warning system in place in this region. If a tsunamigenic earthquake were to occur in this region in the near future, a tragedy with the magnitude similar to the 2004 Indian Ocean tsunami could repeat itself.
In this paper, potential tsunami hazard in SCS region is studied and a procedure for establishing a tsunami early warning system is presented (Satake, 1987, Titov et al., 2001). This system will be capable of releasing early warning information, including both tsunami arrival times and wave heights, to the surrounding countries for earthquakes along the Manila subduction zone. Using this information as input, inundation forecasts will also be possible by applying tsunami runup models in coastal regions of interest.
Section snippets
Hazardous tsunamigenic zones in South China Sea
In the 2006 USGS tsunami source workshop (Kirby et al., 2006), three subduction zones, the Manila subduction zone, Ryukyu subduction zone and N. Sulawesi subduction zone, were identified as having high potentials to generate hazardous tsunamis (Fig. 1).
Preliminary numerical studies have indicated that tsunamis generated from the Ryukyu subduction zone and N. Sulawesi subduction zone will not directly affect countries surrounding the South China Sea. Tsunamis generated from the Ryukyu subduction
Simulation of tsunamis generated along Manila Trench
In this section, we analyze the tsunami arrival time and amplitude distribution using the hypothetical earthquake of magnitude Mw = 8.0 with the fault plane parameters as listed in Table 3. The simulated results will help to identify the correlation between most affected coastal areas with the fractured fault plane segment. The arrival time analysis will also provide important information in selecting the locations of tsunami deep-ocean sensors.
In simulating tsunami propagations, we first assume
General procedures
The establishment of a tsunami early warning and forecasting system involves the following stages:
- •
Deployment of tsunami sensors.
The locations of tsunami sensors in deep-ocean need to be determined based on the understanding on source region characteristics, tsunami arrival times and the coastal areas to be protected.
- •
Construction of unit sources.
The entire subduction zone needs to be divided into small segments; each segment is treated as “unit” source for tsunami generation.
- •
Pre-tsunami
Concluding remarks
In this paper, we have demonstrated that potential for a strong future earthquake along the Manila subduction zone is real. Using a numerical model, we have also shown that most of surrounding countries in the South China Sea will be affected by the tsunamis generated by the future earthquake. The simulated results show that the leading tsunami waves will reach most of coastal communities in China, Vietnam, Malaysia, and Taiwan within 1–2 h. We have proposed a procedure to establish a tsunami
Acknowledgement
The research presented in this paper has been supported by National Science Foundation through grants to Cornell University.
References (11)
Thermal modeling of continental subduction and exhumation constrained by heat flow and seismicity in Taiwan
Tectonophysics
(2000)- Kirby, S. et al., 2006. In: USGS Tsunami Sources Workshop (2006): Great Earthquake Tsunami Sources: Empiricism and...
- Lee, W., 2006. Personal...
- et al.
Numerical simulations of the 1960 Chilean tsunami propagation and inundation at Hilo, Hawaii
- et al.
Run-up of solitary waves on a circular island
J. Fluid Mech.
(1995)
Cited by (106)
Island-based GNSS-IR network for tsunami detecting and warning
2024, Coastal EngineeringForward numerical investigation of potential tsunami deposits in the South China sea: A case study of Nan'ao Island
2024, Marine and Petroleum GeologyTsunami early warning system using offshore tsunameters in Peru
2023, Ocean EngineeringTsunami resonance and standing waves in the South China Sea
2022, Ocean EngineeringDeterministic tsunami hazard assessment and zoning approach using far-field and near-field sources: Study of Cixi County of Zhejiang Province, China
2022, Ocean EngineeringCitation Excerpt :The maximum convergence rate reaches 91 mm/yr at north of Luzon island, estimated by Hsu et al. (2012). The tsunami hazard from the Manila Trench has attracted the attention and interest of many scholars (Liu et al., 2009; Ren et al., 2015; Ren et al., 2017; Li et al., 2016, 2018; Zhang and Niu, 2020). The Ryukyu Trench is located on the west of the Ryukyu Islands.