Oceanologists, however, look deeper - to the seabed - and their research could lead to more efficient measures to tackle natural disasters such as tsunamis.

"The underwater world is one mystery of the Andaman Sea, but the bigger mystery to us is at the seabed," said Dr Anond Snidvong of Chulalongkorn University.

From the shore, the seabed gradually slopes, as most people would imagine. But at some point the slope drops significantly for several kilometres to become a canyon-like feature, called the continental margin area.

"We are talking about an area deeper than 500 metres where the current is strong and the tidal wave underwater is as high as 80 metres," said Dr Somkiat Khokiattiwong of Phuket Marine Biological Centre.

What happens if this canyon feature slides? The answer is a natural disaster.

Anond explains, "If an earthquake reaches this canyon feature and part of it slides, the powerful wave underwater could cause a secondary tsunami. This is just one example of the consequences."

This sounds like a simulation model but it caused major damage when it happened in Papua New Guinea, said German oceanologist Dr Wilhelm Weinrebe.

"That is one reason why we need to know the geography of the Andaman Sea. If we know it enough, we could find measures to prevent disasters," Anond said.

"Satellites' global positioning systems (GPS) can give us a rough picture at one pixel per 100 metres of the Andaman Sea, but site mapping would give us a finer picture at a level of one pixel per 1 to 10 metres. Moreover, GPS is now limited to a depth of only 60 metres in the sea."

The process to map the Andaman seabed in Thailand has kicked off. The Andaman has already been mapped in Indonesia, but India, Burma and Malaysia have yet to tackle the job.

Anond said the mapping of areas less than 500-metres deep would be conducted by a scientific team from the Thai Navy's hydrographic department, sponsored by the Tsunami Fund. The mapping instruments have been bought and staff are being trained.

The mapping of areas deeper than 500 metres, requiring more expertise, is being conducted by a team of Thai-German scientists. The four-year project, involving the National Research Council of Thailand and Deutsche Forschungsgemeinschaft, started last year.

"If we combine both studies, we will get the first map of the Andaman seabed in Thai water. Then disaster-prevention measures for our people along the Andaman coast will be a lot easier and more efficient," Anond said.

"Right now, we have many models for such prevention, but we lack accurate data to input into those models. This is the main problem for our scientists."

This week, the first survey of the Thai-German team will be carried out in Phuket and Phang Nga after a year of preparation. The sample-collecting process will be conducted off-shore from December until next March.

"We have to sail a total of 3,000 miles [5,560km] in the study area in the middle of the Andaman Sea, 200 miles from Phuket's coast," Weinrebe said.

Anond explained that two main instruments would be used: a multi-beam tool and a sub-bottom profiler for both mapping and testing the characteristics of the seabed.

"We need to survey every four kilometres in all of our study area [almost 30,000 square kilometres] per trip. Such surveys will tell us where we should collect samples of soil on the seabed. This should be done by March next year," Anond said.

"To collect samples, we have to drop a tonne-weight cylinder tool underwater, which requires one minute per one metre of water. It takes time to collect each sample, so we have to ensure that we really need to collect that sample."

In the Thai-German scheme, another project is to study the pattern of underwater waves from deep sea to the shallow area near the shore at Similan Island.

"Internal waves from deep sea bring nutrients into shore, but we need to know the pattern and impact of them for further efficient management of marine resources," Dr Somkiat said.

Another four projects are expected to be approved soon this year to complete the jigsaw of the package, Anond said. Among them are studies of soil along the shore in six tsunami-hit provinces of Thailand, in order to study the history of the Andaman Sea.

"Altogether, the package includes studies in the deep sea, shallow sea and on shore," Anond said.

"By the end of project, apart from finding efficient measures to prevent natural disasters, we also expect to use our study results as a database to manage both off-shore and coastal areas in a process of sustainable development."

Kamol Sukin

The Nation