Bangalore: For the first time after the December 2004 tsunami, 18 countries on Wednesday tested the effectiveness of the new Indian Ocean Tsunami Warning Mitigation System (IOTWS).

At 6.30am India time, an undersea earthquake of the same magnitude off the island of Sumatra in Indonesia more than four years ago that led to the tsunami was simulated in the Indian Ocean.

The nations then tested their national warning systems, monitoring how they coordinated with each other.

Mock alert: A man carries his son to higher ground during a tsunami drill in Banda Aceh in Aceh province, Indonesia, on Wednesday. Rahmad Kelana / AP

This centre receives ocean surface data from floating buoys and relays that to the home ministry, which in turn communicates with the state agencies.

Since 2004, an interim system has been in operation, which is led by the Japanese Meteorological Agency and the Pacific Tsunami Warning Centre. “But with IOTWS we will make the transition to a regional system, which is capable of giving a higher level of service," said Kumar. The Pacific system provides warnings based on an earthquake’s magnitude. IOTWS provides warnings by drawing from quantitative estimates of the ocean wave heights.

“Everything is on track," Peter Klaus Koltermann, head of the tsunami unit at the United Nations Educational, Scientific and Cultural Organization, said in an email. The simulated tsunami spread in real time across the entire Indian Ocean, taking around 12 hours to travel from Indonesia to the South African coast.

While some countries such as Indonesia took the drill to the community level, evacuating people in some areas, in India, it was restricted to national, state and district agencies, evaluating their standard operating procedures. None of the drill warnings will be made public, Kumar said.

Mint reported last year that a part of the Indian tsunami warning system, called bottom pressure recorders and installed by Chennai-based National Institute of Ocean Technology, was vandalized by fishermen. “These buoys are not a critical part of the warning system...but we will overhaul the vandalized ones within the next two months," said Kumar.

Many experts say tsunamis, particularly of the kind that caused widespread destruction in December 2004, are once-a-century events and hence maintaining a functional warning system is a challenge. However, as Mint reported in December, research suggests that more tsunamis may be in the making in the eastern Indian Ocean.