Our Kolkata Bureau
What lies beneath the ocean surface remains largely unknown; however, a recent US news report suggests that an American spy agency responsible for drawing up oceanographic maps for the armed forces has been working non-stop to collect information about changes that might have happened to the ocean floor.
The agency's Web site warns mariners traversing the route to proceed with extreme caution as "aids to navigation might have been damaged or rendered inoperable or even destroyed". Thousands of navigational markers such as buoys could have got shifted as also shipwrecks to whose numbers the tsunami has added.
The US spy agency is believed to have received an unconfirmed report that in one area of the Malacca Strait off the coast of Indonesia's Sumatra, the water depth has been slashed from several thousand to several hundred feet.
The Malacca Strait between Indonesia and Malaysia is one of the world's busiest and strategically important shipping lanes. Nearly 40 per cent of the world trade and 80 per cent of Japan's crude oil is transported through this narrow waterway.