As a result of the tsunami disaster, there was much international discussion as to methods by which future tsunamis could be more efficiently and effectively detected, in the hope of preventing future disasters, by buying time - enough time - to potential save hundred of thousands of lives.
On December 26th, 2004 the Indian Ocean had no early warning system, as the Pacific had had since 1949 (see below).
During a United Nations conference held in January 2005 in Kobe, Japan, the Indian Ocean Tsunami Warning System was agreed to, forming an initial step towards an 'International Early Warning Program'.
UNESCO took the lead in coordinating the new international early warning system.
The system became active in June 2006, providing information to those nations bordering the Indian Ocean regarding approaching tsunamis.
Its functioning is very similar to that of the Pacific Tsunami Warning Center (see below).
How the Indian Ocean warning system detects and responds to tsunamis
Also in existence is the Pacific Tsunami Warning Center (PTWC), located in Hawaii, USA. This was established by 26 Pacific Rim countries in 1949, following the 1946 Aleutian Island earthquake and resulting tsunami, and also forms part of an international tsunami warning program.
1. Earthquake detected: Seismic observatories in the region detect an earthquake and send data to the Pacific Tsunami Warning Center in Hawaii.
2. Initial warning: If the earthquake is located in the Pacific basin and is above 7.5 on Richter scale, an initial "Tsunami watch" alert is sent out.
3. Water level checked: Data from monitoring stations on the seabed near the the earthquake's epicentre is checked for any signs of a tsunami.
4. Second warning: If a tsunami is detected, full warnings are sent out via national systems, which have been set up in several countries
The PWTC uses seismic data from the US Geological Survey/National Science Foundation which monitors stations around the world in order to determine when quakes that could trigger a tsunami have occurred.
The Pacific system uses coastal tide guages, along with Deep-ocean Assessment and Reporting of Tsunamis (DART) sensors and buoys in order to detect oceanic changes.
Sensors on the seafloor detect any changes in water pressure, collect this data and send it to the buoys anchored alongside. The buoys then relay the information to tsunami warning centres, via satellite. The sensitive system can detect changes in pressure or rise in sea-level of less than 1 centimetre (half an inch).
The Indian Ocean Tsunami Warning System functions in this way also.
Pacific Tsunami Warning Centre website
