Tsunami Mock Exercise in Indian Ocean

India along with 23 other Indian Ocean Nations, participated in a major Indian ocean-wide tsunami mock exercise (drill) on in September, 2018.

The Exercise, known as IOWave18 was organized by the Intergovernmental Oceanographic Commission (IOC) of UNESCO, which coordinated the setting up of the Indian Ocean Tsunami Warning and Mitigation System (IOTWMS) in the aftermath of the 26 December 2004 tsunami.

A tsunami or tidal wave, also known as a seismic sea wave, is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions (including detonations of underwater nuclear devices), landslides, glacier calvings, meteorite impacts and other disturbances above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water.

‘IOWave18’ focused on a simulatingan earthquake with magnitude of 9.3 at Northern Sumatra, Indonesia. All eastern coastal states participated till community level.

In India, ‘IOWave18’ is being coordinated by the Indian National Centre for Ocean Information Services (INCOIS), Ministry of Earth Sciences (MoES) with support from National Disaster Management Authority (NDMA), Ministry of Home Affairs (MHA), National Disaster Response Force (NDRF) and the Coastal States/UTs.

In this exercise, over 1000 people were evacuated in Andaman & Nicobar. Similarly, in West Bengal over 1200 people were evacuated in 3 districts. In Tamil Nadu, 13 districts participated with 5054 people being evacuated. There were around 100 evacuees in Puducherry. In Andhra Pradesh 9 districts participated with over 8020 evacuees. Odisha had a participation of 6 districts (328 villages) with around 1,00,000 people evacuated.

Overall over the 2-day exercise, all coastal states tested communication modes for receipt of bulletins from INCOIS. The end-to-end warning system from tsunami detection and forecast, threat evaluation and alert formulation, alert dissemination to public and their awareness and response was put to test during this exercise.

Where possible states participated up to community-level with practice evacuations. 44 Coastal Districts of 9 States/UTs are participated up to community level. Community level evacuations were carried out in around 375 villages. Over 125,000 people were evacuated during the exercise.

The 2004 Indian Ocean earthquake occurred on 26 December, with an epicentre off the west of 9.1–9.3 and a maximum Mercalli intensity of IX (Violent). It was an undersea megathrust earthquake caused by rupture along the fault between the Burma Plate and the Indian Plate.

The 2004 Indian Ocean earthquake triggered a series of devastating tsunamis up to 30 metres (100 ft) high, inundating coastal communities along the coasts of the Indian Ocean and killing an estimated 227,898 people in 14 countries, with the majority of victims being killed in the Indonesian city of Banda Aceh. The earthquake was one of the deadliest natural disasters in recorded history, the deadliest of the 21st century so far. Indonesia was the hardest-hit country, followed by Sri Lanka, India, and Thailand.