Tsunami Warning

The giant waves that hit many Asian countries in 2004 killed more than 300,000 people, making them one of the worst disasters in recorded history. Since then, there has been a flurry of activity to develop tsunami early warning systems.

Germany's National Research Center for Geosciences (GFZ) is currently installing such a system in Indonesia -- but it could save lives in other regions as well.

Ten percent of all tsunamis world-wide occur in the Mediterranean. In 2003, a two meter (6.6 feet) high tsunami hit the coast of Algeria and Spain's Balearic Islands causing significant damage, but no loss of life. And back in 1908, some 75,000 people died when giant waves swept along the Sicilian coast.

Warning system in five or 10 years

Nearly all tsunamis are caused by underground earthquakes, which typically occur at boundaries between Earth's tectonic plates. Large waves then begin to move through the ocean, away from the earthquake's epicenter. Tsunamis can be up to 30 meters high and reach speeds of to 1,000 kilometer per hour (621 mph).

Earthquakes in the Mediterranean are mainly caused by the African Plate drifting northwards underneath the Eurasian Plate.

"Tsunamis could happen at any time, and could be catastrophic", said Jochen Zschau, the head of GFZ's Earthquake Risk Department.

With 140 million people living along the Mediterranean coast, the potential for a disaster is high. But according to Zschau, with so many countries surrounding the Mediterranean, coordination of an early warning system is difficult. He estimates that installing such a system in the region would take five to 10 years.

Real-time transmission

The 45-million-euro ($60.8 million) GFZ project to install early warning buoys in the Indian Ocean off Indonesia is due for completion in 2008. The system uses sensors on the ocean floor to detect changes in pressure. This is sent to a series of buoys on the ocean surface, which, in turn, beam the data by satellite to an observation station. By using real-time data transmission, tsunamis can be detected more quickly, which gives people more time to flee the oncoming waves.

Germany's Federal Ministry of Education and Research, which commissioned the Indonesian project, set the condition that the system would also be usable for the Atlantic and the Mediterranean oceans.

"A large part of the early warning system in the Indian Ocean can be transferred to the Mediterranean," Zschau said. "But of course not all factors are the same, so the system needs to be adjusted for the particular region."

Because the Mediterranean is a smaller ocean, it takes a tsunami less time to travel from the earthquake's epicenter to the coast. This means the early-warning window is less than for other regions.