In 2004, when the Indian Ocean Tsunami hit 14 countries and killed more than 230,000 people, there was no tsunami warning system present in the Indian Ocean - nor in many other regions. “In fact, apart from the Pacific, there was almost no exchange of real-time data that is needed for tsunami warnings, and no deep-ocean monitoring systems in place,” says Denis Chang Seng, programme specialist for the Tsunami Resilience Section at the Intergovernmental Oceanographic Commission of UNESCO (IOC/UNESCO).

Fast forwarding to 2023, the progress of tsunami warning systems has been tremendous. “Today, there are regional Tsunami Warning Systems in each of the four major ocean basins, with a total of 11 Tsunami Service Providers issuing tsunami threat advice to Tsunami Warning Centres established in each country” says Rick Bailey, Head of Secretariat for the IOC/UNESCO Intergovernmental Coordination Group for the Indian Ocean Tsunami Warning and Mitigation System (ICG/IOTWMS). 

Many coastal areas now receive tsunami threat advice within 10 to 20 minutes after a potentially tsunami-generating undersea earthquake is detected. “It is still technically challenging, however, to generate a timely and accurate tsunami warning in a short amount of time in the case of major earthquakes, and especially if the epicenter is not far from the coast,” says Chang Seng. 

Tsunamis are known for their high speed - in deep water they are small and can move as fast as a jet plane, crossing entire oceans in less than a day, before slowing down and shoaling to greater heights in shallow water. In this race against time, every minute lost in receiving a warning can lead to a devastating toll on human lives - but various new technological advancements hold the key to ensuring swifter and more accurate tsunami alerts even in the most challenging cases. Below we share the developments that are shaping the future of tsunami warnings.