BioEd Online

Almost a year after the catastrophic Indian Ocean tsunami, scientists are busy installing buoys off the coast of Sumatra to help with future warning systems. At the same time, experts and politicians are meeting to discuss how the northeastern Atlantic and Mediterranean might be similarly protected.

This month, Indonesian and German scientists installed two buoys and deep ocean pressure sensors in the Indian Ocean, to help monitor sea levels and detect the tell-tale signs of a tsunami. Reports say they should be up and running by the end of the year.

Deployed off the coast of Sumatra, they are some of the first elements of a planned tsunami warning system for the region, whose final details will be agreed next year by the Intergovernmental Oceanographic Commission (IOC), based in Paris.

About 23 real-time sea-level stations are planned to be upgraded or installed by the end of 2005, and the whole warning system could be operational as soon as 2008.

Elsewhere in the world

The Sumatra system was called for after the disastrous wave struck in December 2004. But researchers at the time warned that other parts of the world also needed protecting from tsunamis.

To that end, an intergovernmental panel of the IOC met from 21 to 22 November in Rome to hash out early details of a warning system for the northeastern Atlantic and Mediterranean.

The panel decided to improve the seismographic network already in place, helping to make information available in real time. It also decided to beef up the capacity of ocean buoys, but was unable to come to any firm decisions about ocean pressure sensors, which could be a crucial part of an Atlantic early warning system.

At risk

The northeastern Atlantic and Mediterranean have no large-scale tsunami warning networks. There is just one small one, around Stromboli in Italy, where a local system was installed after a landslide in December 2002.

Yet the region has a history of deadly waves. An earthquake and ensuing tsunami that struck Lisbon in 1755 is thought to have killed 60,000 people. Countries from Nova Scotia to Norway have also been struck by tsunamis. And one killer wave in Greece is thought to have killed more than 100,000 people in 1410 BC. Sprawling coastal development means that any tsunami today could have far more catastrophic effects.

"The Mediterranean has a higher probability of tsunamis than the Indian Ocean," says Keith Alverson, director with the IOC's Global Ocean Observing System.

Close to danger

Furthermore, many potential sources of tsunamis, including seismic zones, underwater volcanoes and slopes at risk of landslides, are quite close to shore in the Mediterranean.

This means there would be little time to react to signs of an incoming wave. The trigger for the tsunami in the Indian Ocean was detected hours before some countries were hit by the wave; a tsunami in the Mediterranean would smash on to surrounding coasts within minutes. So any warning system will need to be heavily automated, says Alverson.

Data from seismic networks in the region is currently sampled and transmitted at around fifteen minutes intervals, says Patricio Bernal, executive director of the IOC. "We need reporting in seconds," he told news@nature.com from the Rome meeting. "It is a very demanding requirement."