Matthew Alford, associate director of the Marine Physical Laboratory and head of the Oceans and Atmospheres Section of the Scripps Institution of Oceanography, says that the U.S., China and Russia 'have spent a lot of money' studying internal waves in the South China Sea because of their potential impact on naval operations in the strategic waterway. They are also known to exist in the Lombok Strait area in Indonesia, where the Nanggala was lost. Internal waves occur in specific ocean regions around the world – places such as the Strait of Gibraltar that links the Mediterranean with the Atlantic Ocean, parts of the Western Pacific and the South China Sea.
They are generated by the interplay of strong tides, warmer and cooler ocean layers and the undersea geography. Such waves - while seldom noticed by observers on the surface - can reach dizzying undersea heights and therefore cause concern for submarines, scientists say. Asia Indonesian Navy Loses Contact With Submarine 53 Aboard
