Radio signals that may have been emanating from the flight recorder of Malaysian Airlines Flight 370 marked the beginning of a new phase of the search for the aircraft and its passengers. Once signals emerged, the investigation expanded to include exploration of the ocean floor to detect the aircraft and recover the block box.
The location of the black box is estimated to be about 15,000 feet (4.6 kilometers) below the ocean surface. The pressure at such depths in the ocean is about 455 times the atmospheric pressure at sea level. The remains of Titanic are located at a depth of 12,500 feet (3.8 kilometers) depth, which has pressure of about 380 atm. The additional 2,500 feet increases the pressure by 75 atm. In addition, the temperature is only 34 to 40 degrees Fahrenheit (1 to 4 degrees Celsius) at such depths.
via How Submarine Foams Withstand the Crushing Pressures of the Deep Sea | LiveScience.
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