Tsunamis

Geographic Areas Covered by the TEWS

©UNESCO
Geographic Areas Covered by the TEWS

Earthquakes beneath the ocean floor, volcanic eruptions, submarine landslides and even meteorite impacts can touch off the monstrous waves known as tsunamis. Barely perceptible in the deep ocean, a tsunami travels at the speed of a commercial jet plane but slows down when it hits shallow waters and rears up onto land. Because not all submarine earthquakes result in destructive tsunamis, and because not all tsunamis are triggered by earthquakes, the killer waves cannot be detected by seismological observations alone.

 

 

These have to be supplemented with deep-sea pressure sensors and satellite-linked buoys. Under the auspices of UNESCO, the Global Ocean Observing System (GOOS) is an intermeshed network using ships, buoys, subsurface floats and orbiting and geostationary satellites to examine the mysteries of the world’s vast bodies of water. The complex science serves no purpose unless it can be converted into effective warnings, which requires the building of national centres to receive warnings from observation networks and relay them to communities in harm's way through clear, previously identified channels.

This was painfully obvious following the giant tsunami of December 2004 in the Indian Ocean: scientists were immediately aware of the massive earthquake on the sea floor off Sumatra that spawned the tsunami, but there was no way of sounding the alarm that a tsunami might be imminent. Within a month of the resulting disaster, governments at the WCDR in Kobe in 2005 meeting agreed to set up a tsunami warning system for the Indian Ocean similar to that already operating in the Pacific Ocean since 1968. Going further, Member States of the Intergovernmental Oceanographic Commission of UNESCO decided at their General Assembly in June 2005 to coordinate the establishment of a global warning system for ocean-related hazards in close cooperation with other UN bodies.

Harnessing the capabilities of existing detection networks, tsunami warning systems have been placed in recent years in Africa, the South Pacific, the North-East Atlantic and the Caribbean. These are expected to eventually form part of a global warning and mitigation network being coordinated by the Intergovernmental Oceanographic Commission. This, in turn, will contribute to the Global Earth Observation System of Systems (GEOSS), a worldwide effort involving 60 countries, the European Commission and 43 international organizations.

For more information: http://www.ioc-unesco.org/

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