Mir Fazlul Karim, a director of Geological Survey of Bangladesh (GSB), told BSS that the shallow water on the continental shelf of Bangladesh slowed down the onrushing sea surges before they could ravage our coastline.

Karim is heading a team of experts working with the help of the United States Geological Survey (USGS) to study the impact of the earthquake that triggered the massive tsunami, or sea surge, which ripped through a wide area of the Indian Ocean from Sumatra to Somalia

The continental shelf, which stretches 200-km into the Bay of Bengal, was created on the Gangetic delta by billions of tonnes of sediment carried by the Ganges and the Brahmaputra.

The depth of water on the Bangladesh coast is 10 to 20 metres, Karim said, which helped to absorb the impact of the onrushing sea surges whipped up by the tsunami effect.

"Though we have survived with god's mercy and the natural barrier, we are yet to be out of the woods as danger is always lurking. We need to develop a system of early warning against more powerful sea surges," Fazlul Karim said, adding that there is no system of predicting earthquakes.

Karim and three other GSB colleagues--Sirajur Rahman Khan, Khorshed Alam and Nasima Begum--comprise a committee entrusted with the job of thoroughly studying the impact of the December 26 earthquake-triggered tsunami and developing an early warning and model of survival for Bangladesh against such an occurrence.