ocean-floor map

基本解释

Two key pieces of evidence -- the flight data and cockpit voice recorders -- remain missing and could lie on the ocean floor. Map of Flight 447's flight path »
两件关键证据——飞行数据和驾驶舱录音器——仍未找到，可能已经沉入海底。

Once there, they use aerial photography and remote cameras in combination with depth-finding and global-positioning satellite technology (as well as some first-hand testing of the waves) to measure the waves and map the contours of the ocean floor under the breaks.
ECONOMIST: On the beach
The Neil Armstrong, first of the Armstrong-class Auxiliary General Oceanographic Research (AGOR) ships, will be equipped with sonar to map the ocean floor and laboratories for experiments.
FORBES: U.S. Navy Names Ship After Neil Armstrong