Guarding India’s shores: Advancing tsunami preparedness

Two decades have passed since the 2004 Indian Ocean Sumatra tsunami. Before this catastrophic event, the term “tsunami” was largely limited to science fiction, themes in films, or incidents occurring in distant parts of the world. The December 26, 2004, tsunami starkly highlighted the urgent need for robust warning system, particularly one capable of predicting coastal inundation and run-up.

The author attempts to review the current status of India’s Early Warning System, which integrates cutting-edge technology to enhance tsunami preparedness and mitigation.

The devastating 2004 tsunami, which caused unprecedented loss of life and property, underscored the necessity for a robust early warning system. The Indian National Centre for Ocean Information Services (INCOIS), based in Hyderabad, has been at the forefront of ocean-related research and services in India. One of its most notable contributions is the Tsunami Early Warning System (TEWS)

INCOIS, in collaboration with the Ministry of Earth Sciences (MoES), established the Indian Tsunami Early Warning Centre (ITEWC) in 2007. Over the years, the ITEWC has evolved into a state-of-the-art facility capable of issuing real-time warnings for tsunamis triggered by earthquakes, landslides, and other oceanic disturbances. Following are the key components of the early warning system: 

Monitoring of real-time seismic activity: INCOIS operates a network of more than 300 seismic stations spread across the
Indian Ocean, using advanced Global Seismic Network (GSN) technology. These stations can detect earthquakes as small as magnitudes 5 on the Richter scale within seconds. Parameters such as epicentre, depth, and magnitude are analysed to assess tsunami potential.

Deep-ocean Assessment and Reporting of Tsunamis (DART): A network of DART is strategically deployed to monitor minute changes in sea level caused by underwater seismic activity. These buoys relay real-time data to ITEWC via satellite communication. The latest versions of DART buoys are more durable and equipped with advanced sensors for greater accuracy. Besides, supporting systems such as bottom pressure recorders and tide gauges, help track tsunami propagation.

Numerical modelling: Numerical Modelling recreates tsunami scenarios using equations in mathematics and physics. A tsunami or tsunamigenic earthquake can happen due to several different permutations and combinations of seismic parameters. These are simulated as pre-run scenarios and stored in electronic formats.

These enable rapid identification of potential matches during real-time events. Vulnerability maps are generated to guide evacuation and mitigation efforts. Recent advancements include numerical models that simulate tsunami wave propagation and arrival times using artificial intelligence (AI) and machine learning (ML) algorithms. These tools enhance prediction accuracy and allow the creation of inundation maps within minutes of an event.

Satellite monitoring: Satellite datasets provide real-time observation of sea surface heights, which complements data from DART buoys. This integration ensures comprehensive monitoring, particularly in regions with limited buoy coverage.

Decision support system (DSS): The DSS processes real-time data from seismic stations, DART buoys, and numerical models. This system provides automated decision-making support, enabling rapid generation and dissemination of warnings. Alerts are categorised based on threat levels—watch, warning, or advisory—and are tailored for specific regions.

Multi-channel communication system: To ensure timely dissemination of warnings, INCOIS has adopted the Early Warning Dissemination Systems (EWDS), which can integrate SMS, satellite phones, email, and social media for fast and reliable communication. Automated sirens along the coastline further enhance public alert systems.

Community engagement activities: Smart phone apps and social media platforms enable coastal communities to report unusual oceanic observations, improving real-time monitoring.  

The Indian Tsunami Early Warning Centre is a designated Tsunami Service Provider (TSP) for the Indian Ocean region under UNESCO’s Intergovernmental Oceanographic Commission (IOC). INCOIS provides tsunami alerts to 28 countries, showcasing its technological and scientific expertise. INCOIS had proven its effectiveness, as demonstrated during the 2012 Indian ocean earthquake, when timely warnings enabled precautionary evacuations. Regular mock drills and training sessions conducted by INCOIS have improved community preparedness along India’s coastline. Ongoing advancements include quantum computing for faster data processing and underwater drones for enhanced seismic and oceanographic data collection. 

India’s Tsunami Early Warning System operated 24/7, leveraging seismic networks, bottom pressure recorders, tide gauges, and advanced communication systems. It is backed by a robust database,  vulnerability modelling, and decision support systems. 

Tsunamis primarily result from tectonic plate movements and collisions. Research is underway to map tectonic trajectories, enabling the prediction of tsunamigenic earthquakes. With these developments, India’s tsunami early warning capabilities are poised to become even more effective. 

(The writer is an assistant professor in Physics, St Thomas College, Pathanmthitta, Kerala, and former project scientist, National Centre for Coastal Research, Government of India, Chennai, & Former Project Scientist, Centre for Atmospheric Sciences, IIT Delhi)