14 countries, 2 lakh deaths… the 20-year-old tsunami that wreaked havoc in the Indian Ocean

On the morning of 26 December 2004, the Indian and Burmese tectonic plates moved 30 km below the surface of the earth, west of Indonesia's Sumatra island. This movement triggered one of the most devastating earthquakes in history. The magnitude of the quake was 9.1—so strong that high waves began to rise in the Indian Ocean.

The waves were moving towards the shores at a speed of 800 km/h. As they hit the shores, their height increased rapidly. These 57 feet high waves caused devastation in 14 countries. Water swallowed cities and villages, thousands of houses were destroyed, and millions of lives were ruined. Even after 20 years, this scene cannot be forgotten. It is counted among the biggest tragedies of the world.

More than 2 lakh deaths in 14 countries

This tsunami took the lives of more than 2.3 lakh people. The maximum damage was done in Indonesia, where 1.72 lakh people died. More than 37 thousand people went missing. In India too, more than 16 thousand people became victims of this disaster. More than eight thousand people died in Tamil Nadu state alone. And 3 thousand 515 deaths occurred in Andaman and Nicobar. Hundreds of fishermen went missing from the southern coast of India, whose bodies were later recovered floating in the sea. Lakhs of people became homeless in Sri Lanka. President Chandrika Kumaratunga declared a national emergency. Other countries affected by the tsunami were Thailand, Malaysia, Maldives and Seychelles.

Why did such a terrible tsunami occur?

Research published in the journal Science on 26 May 2017 revealed that the cause of the devastation that occurred on 26 December 2004 was the Himalayas. In fact, the epicenter of the earthquake in Sumatra was at a depth of 30 kilometers in the Indian Ocean, where the tectonic plate of India touches the boundary of the tectonic plate of Australia.

For thousands of years, the sediments eroded from the Himalayas and the Tibetan Plateau travelled thousands of kilometres through the Ganges and other rivers and got deposited at the bottom of the Indian Ocean. These sediments deposited at the bottom of the Indian Ocean also get collected at the border of the plates, also known as the subduction zone, which causes devastating tsunamis.