Scale of Destruction: Tsunamis can range from minor, imperceptible occurrences to catastrophic events. For example, small tsunamis caused by minor underwater disturbances often go unnoticed unless monitored.

Human Toll: The 2004 Indian Ocean tsunami claimed over 225,000 lives across 14 countries, while the 2011 Tōhoku tsunami in Japan caused nearly 16,000 deaths and forced over 300,000 people into temporary displacement.

Infrastructure Collapse: Coastal infrastructure-including homes, bridges, and roads-is often obliterated. The 2011 Japan event led to unprecedented damage valued in hundreds of billions of dollars. For example, in the 2025 Kamchatka event, flooding in Russia’s Kuril Islands caused damage to homes and facilities. In Japan, even a 0.6 m wave led to the evacuation of nearly 2 million people.

Environmental Degradation: Tsunamis disrupt ecosystems by destroying coral reefs, mangroves, and wetlands. Saltwater inundation also contaminates freshwater systems and soil, severely affecting agriculture and biodiversity.

Secondary Hazards: Post-tsunami effects include hazardous material leaks, fires, and cascading disasters. The Fukushima Daiichi nuclear meltdown following the 2011 Japan tsunami exemplifies such compound calamities.

Health and Psychological Impact: Victims often face waterborne illnesses, overwhelmed health services, and long-lasting mental health issues such as PTSD. Survivors struggle with loss of property, routine, and emotional trauma.

Service Disruptions & Displacement: Essential services-electricity, water, and communication-are typically knocked out, while widespread displacement strains relief and rehabilitation systems.

Global Ripple Effects: Major tsunamis such as the ones in the Indian Ocean and Japan had far-reaching impacts on global trade, tourism, and supply chains, especially when key ports are disrupted.