Large-amplitude internal waves observed off the northwest coast of Sumatra

Internal waves of large amplitude were observed north of Sumatra by the U.S. Coast & Geodetic Survey ship Pioneer in June 1964. The bathythermograph investigation which defined these waves was initiated after observation of curious periodic surface phenomena resembling tide rips. Analysis of bathythermograph records indicates that internal waves with a maximum observed wave height of 82 meters are the probable cause of the surface disturbances.