Design and commissioning of a tsunami warning system in the Pacific

Context and challenges

The risk of a tsunami is ever present in the Pacific Ocean, which is surrounded by a "ring of fire". The Pacific Tsunami Warning Center (PTWC Hawaii) monitors risks of seismic events and water levels, supplying national warning centres with messages and notices in case of strong earthquakes and risks of tsunamis in the Pacific Ocean.

Since the tsunami of December 2004, France has focused on the risk looming over its Pacific territories (French Polynesia, New Caledonia, Wallis and Futuna). Polynesia operates a seismic and volcanic activity monitoring centre (LDG), which is responsible for alerting the civil protection authorities of French Polynesia in case of a major seismic event.

Although the warning centres are effective throughout the region, the main obstacle to overcome is reaching "the last mile". The issue is ensuring that populations near to the source of a tsunami can react rapidly and that people living in remote and isolated areas are warned of the risk of submersion in time. This problem is all the more complicated for French Pacific areas which cover two immense Exclusive Economic Zones (EEZ) of 5 million km² and 1.5 million km², 4,600 km apart and containing around 85 inhabited islands.

In this context, the national civil protection organisation appointed Assystem to deploy a tsunami warning system in the French Pacific (Polynesia, New Caledonia, Wallis and Futuna), delivering preliminary design right through to commissioning.