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5,000 fathoms (9,144 meters
| Морской словарь |
30,000 feet). this depth can be compared to the height of mount everest, the highest point on earth, whose summit is 8,848 meters (29,029 ft) above sea level. these six are: the hydrostatic pressure at such depths is in the order of 16,000 pounds per square inch (1,125 kg/m2).
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Hydrostatic, английский
Гидростатический
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Oceanic sound channel, английский
Sounds in the sea can often be “trapped” within this channel, which is caused by temperature and pressure differences that allow low-frequency acoustic waves to travel long distances without significant loss of energy. descending through the epilimnion, temperature drops and the speed of sound decreases until—at the bottom of the thermocline—both speed and temperature reach their minimums. this is the axis of the sound channel. below this level, in the hypolimnion, temperature remains constant, but pressure increases, causing the speed of sound to rise again. because acoustic waves tend to refract towards the area of minimum speed, a wave will be confined within the sound channel, bending alternately up and down as it travels. obstacle 224 trench name fathoms meters feet izu bonin 5,348 9,780 32,086 kermadec 5,494 10,047 32,962 philippine 5,740 10,497 34,438 kurile 5,764 10,542 34,586 tonga 5,950 10,882 35,702 marianas 5,973 10,924 35,839 the channel lies between 330 and 660 fathoms (600–1200 feet) below the surface, being deepest near the tropics and moving closer to the surface at high latitudes. by placing hydrophones on the axis of the channel it is possible to detect whale calls, seismic activity, propeller signatures, and other human-made noises from far away, sometimes across entire ocean basins. this is the principle behind the sound fixing and ranging and sound surveillance systems. see also ocean acoustics.
Oceanic deep, английский
A depression in the sea floor deeper than 3,000 fathoms. there are deeps in each of the thirteen oceanic trenches that form the ring of fire, and six of them descend below sea level for more than
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