The underwater earthquake and resulting tsunami that devastated South Asia have made major changes to the floor of the Indian Ocean. Those shifts could drastically affect shipping and the region's environment for years.
The Indian Navy is pulling sonar transmitters through the water, trying to assess the damage the tsunami has done to the ocean floor. In one spot, the bottom is littered with debris and sunken boats. The navy has already removed 26 boats.
Divers took an ABC News [a U.S. TV network] crew on an underwater tour of the murky debris field.
The U.S. is getting reports from ships in the region, indicating the tsunami has literally reshaped parts of the ocean floor. Ships in the Molacca Straits off Indonesia report dangerous new sandbars, or shoals, making once-deep water now very shallow.
Retired Rear Admiral Chris Andreasen of the National Geospatial-Intelligence Agency says, "The chartered depths were 4,000 feet and the reported depths are [now] 100 feet -- it's a phenomenal shoaling reported there."
Satellite photos of Indonesia's Aceh Province before and after the tsunami show large sections of coastline were washed into the sea.
Keith Dominic is also with the National Geospatial-Intelligence Agency. "So far we have seen significant major navigation aids that have been extinguished or no longer exist."
In fact, after the tsunami, the Indian Navy discovered every buoy in one harbor out of place or missing. Officials are now using global satellite positioning to relocate those buoys.