The Pacific Tsunami Warning System, which has been coordinated by the IOC of UNESCO with cooperation from other UN agencies and dozens of nations, was called into action by the high-magnitude earthquake and subsequent destructive tsunami which occurred 11 March, 2011 05:46 (GMT). Within three minutes of the earthquake, the Japanese Meteorological Agency issued a Major Tsunami Warning. Six minutes later warnings or watches were issued for islands from the South Pacific to Hawaii, as well as Japan and Russia.
Tsunami Warning System sea level gauges immediately reported the arrival and amplitude of tsunami waves along the Japanese Coast (http://www.jma.go.jp/en/tsunami/observation_04_20110311181349.html). In the subsequent 24 hours, the Tsunami waves were tracked across the ocean, and warnings were issued for North and South America.
The IOC Tsunami Warning Centers (http://ioc-tsunami.org) work in close cooperation with national agencies. The IOC is primarily concerned with international coordination among nations, while the operational duties of the centers reside with national agencies. For instance in the Pacific, the Japanese Meteorological Agency, the Pacific Tsunami Warning Center, and the West Coast/Alaska Tsunami Warning Centre have operational responsibility for issuing international advisories to country national authorities. The JMA has been an integral part of the Pacific Tsunami Warning System, which was established under the leadership of IOC in 1965. Since the Indian Ocean tsunami of 2004, the UN has designated the IOC to lead in the coordination of regional Tsunami Warning and Mitigation Systems in the Indian Ocean, the Caribbean, and the North-eastern Atlantic and Mediterranean.
Tsunami early warning systems are based on observation networks of seismometers and sea level measuring stations, which send real time data to national and regional tsunami warning centers (TWCs). Based on these observations, TWCs are able to evaluate the potential for a given earthquake to generate a tsunami, and confirm or cancel a tsunami warning advisory. When a potentially destructive tsunami is detected, national authorities decide if a tsunami warning and an evacuation order must be issued to their public.
Tsunami warning systems are complete end to end warning systems, involving advanced technology, as well as comprehensive learning activities to teach coastal populations about tsunami danger and how to respond to a tsunami. For local tsunamis, where the wave arrives in minutes, everyone must recognize the natural tsunami warning signs and act immediately to save their lives by moving to higher ground. The priority of the IOC programmes is to reduce risk, by encouraging communities to implement effective preventive measures and become aware of the hazards they face.
The IOC conducted the East Africa and West Indian Ocean Training Workshop on Tsunami Warning and Emergency Response Standard Operating Procedures, 15-19 November 2010, Dar es Salaam, Tanzania. 26 participants from 8 countries (Comoros, Kenya, Mauritius, Mozambique, Seychelles, South Africa, Tanzania) attended. Trainers were from Pakistan and IOC (Paris, ITIC, Perth).