Two decades after the catastrophe: Reflections and lessons from the 2004 Indian Ocean tsunami

The 2004 Indian Ocean tsunami was one of the deadliest natural disasters in recorded history, claiming approximately 230,000 lives across multiple countries. In two decades’ time, significant advancements have been made in tsunami early warning systems, research, and disaster preparedness. This paper reviews the impact of the 2004 tsunami, analyses past and recent tsunami events, and highlights the development of global and regional tsunami mitigation strategies from the data publishedin research articles. Key initiatives have revolutionised tsunami detection and response, including the Indian Ocean Tsunami Warning and Mitigation System (IOTWMS), GNSSbased monitoring systems, and ocean-bottom sensors. Additionally, community-based programs, such as India’s “Tsunami Ready” initiative, have enhanced coastal resilience. While technologicaladvancements have improved early warning capabilities, further efforts are required to ensure widespread awareness, preparedness, and rapid response mechanisms. This review underscores the necessity of continuous innovation, internationalcollaboration, and community engagement to mitigate the catastrophic effects of future tsunamis.