JAKARTA, July 19: Compared with the giant Asian tsunami of Dec 2004, the walls of water that lashed Indonesia’s Java island this week seemed small but the waves were powerful and fast, an expert said Wednesday.

The luckless inhabitants along the coast were struck by seawater that rose to a three-metre wave and then stretched six to seven metres high once it reached inland, killing more than 500 people.

“The wave was not very high, but very violent,” said Franck Lavigne, who heads Tsunarisque, a joint French-Indonesian research and prevention programme focusing on tsunamis.

The researcher from the University of Paris, currently visiting the affected area, insists this was in no way a “mini-tsunami”.

“This is false. People are so focused on the completely exceptional event that occurred at Aceh, that some are speaking about this being a mini-tsunami. But it was a completely normal tsunami,” he told AFP from Pangandaran.

Indonesia’s Aceh province bore the brunt of the major tsunami in December 2004 which killed about 168,000 people, out of the estimated 220,000 who lost their lives across 11 Indian Ocean nations.

Lavigne has already begun studying the trajectory, power and impact of the latest tsunami on the south coast of Java.

“All the houses which had only one floor were destroyed. The others have a hole in place of the lower level,” he said.

The fact that even large, solid hotels had their frontage smashed in demonstrated the “impressive force” of the tidal wave, he said.

Deadly water rushed approximately 500 metres (1,659 feet) inland, according to initial work carried out by Lavigne’s team, although it may have gone further in certain zones, such as along the mouths of rivers.

Tsunarisque, involving seven French and Indonesian universities as well as several specialised public organisations, was set up to study the 2004 Asian tsunami.

Through numerical modelling, its experts estimated that the waves reached a maximum height of 33 to 34 metres along the north-western coast of Sumatra.

The researchers also studied the direction of tree trunks that lay strewn after the disaster and twisted metal, in order to distinguish the orientation of the waves on their arrival at the coast and during their withdrawal.

They finally set up a project aimed at educating the coastal villages of Indonesia, an archipelago which frequently suffers earthquakes due to its location along the Pacific “Ring of Fire” where continental plates meet.

In a sad twist of fate, Tsunarisque’s mission was due to travel next week to Pangandaran and Cilacap — the areas worst hit by this week’s tsunami — to show films and distribute thousands of posters and booklets about the phenomenon.

“It is really bad luck,” a sombre Lavigne said.

FRESH TREMOR: An aftershock in Indonesia’s tsunami-ravaged region and a new tremor off the south-western Java coast sowed fear on Wednesday as the toll from Monday’s disaster climbed to 550.