Predicting or Forecasting Tsunamis

After the tsunami of December 2004, officials have directed concerted efforts into the development of early warning systems, designed to raise the alarm and minimise the number of lives lost. 

Moored buoys, tide gauges and satellite communications linked to observation centres were all top priority for the Indian Ocean region.

But warning systems consist of more than advanced technology.  Educating residents in tsunami prone areas on warning signs and how to best prepare themselves and their families is also imperative.

Two examples of US educational initiatives are the TsunamiReady and related StormReady programs which were designed to educate emergency management officials and help them to create viable tsunami emergency management plans for their local communities.

Japan is perhaps the best prepared nation, a result of being one of the world’s most earthquake prone countries. 

The Tsunami Warning Service (TWS) was established in 1952 and is run by the Japan Meteorological Society (JMA). This system is comprised of over 300 sensors which are monitored around the clock. 

And if an earthquake is determined to have tsunami potential, the JMA will issue a warning within 3 minutes with alerts broadcast over every TV and radio station to give necessary evacuation information. 

The TWS system is so sophisticated, it can not only predict a tsunami prior to strike but can also predict the height, speed and destination of any tsunami threatening Japanese shores with amazing accuracy.

TWS also immediately notifies local officials so they can prepare to act quickly. 

But as with any disaster management plan, preventative measures are crucial to its success.  The foundation of Japan’s system is its strict adherence to new building regulations which protect against tsunamis and earthquakes.  This vast system of tsunami walls, stronger buildings, emergency shelters, floodgates and rapid response times have saved many lives and many companies offering preventative measures.

In 1993, a 30 metre tsunami struck Hokkaido taking a toll of 239 lives compared to the 230,000+ lives lost from the Indian Ocean tsunami in 2005 of the same size.

Though the Japanese system is a prime example of vigilance, it comes at a relatively high price which poorer nations could not afford; $20 million per year. 

For all of these measures, Japan remains at risk and worst-case scientific models estimate death tolls of 12,700 people if three simultaneous strong earthquakes with pursuant tsunami were to occur.

Tsunamis are generally more prevalent within the Pacific coastal regions but can occur anywhere globally where a significant displacement of water occurs as a result of earthquake, volcanic eruption or even nuclear explosion.

Even the most technologically advanced early warning system is ill equipped to prevent devastation.  But signs which indicate the imminence of tsunami waves, such as an earthquake near water or a receding water line which exposes areas that are normally submerged, can give the few minutes of warning that may be crucial in saving lives.

Diagram of tsunami early detection system.