Ocean cold as water at greater depths. Below the thermocline, water is very cold, ranging from −1 °C to 3 °C. Because this deep and cold layer contains the bulk of ocean water, the average temperature of the world ocean is 3.9 °C. If a zone undergoes dramatic changes in salinity with depth, it contains a halocline. If a zone undergoes a strong, vertical chemistry gradient with depth, it contains a chemocline. The halocline often coincides with the thermocline, and the combination produces a pronounced pycnocline. The deepest point in the ocean is the Mariana Trench, located in the Pacific Ocean
How Deep Is the Ocean? How Deep Is the Ocean? "How Deep Is the Ocean " is a popular song written by Irving Berlin in 1932. The song was developed from an earlier Berlin song "To My Mammy" which was sung by Al Jolson in his film "Mammy" (1930). In the earlier song, the lyrics include the questions "How deep is the ocean? / How high is the sky?" and this was the genesis of "How Deep Is the Ocean?". The song was written at a low point in Berlin's professional and personal life, and is among the select few of his numbers that were