The
Challenger Deep is the deepest surveyed point in the oceans, with a depth of about 11,000 metres (about 36,000 feet). It is located in the
Mariana Islands group at the southern end of the
Mariana Trench. The closest land is
Fais Island, one of the outer islands of
Yap, 289 km southwest and
Guam 306 km to the northeast. The point is named after the British
Royal Navy survey ship
HMS Challenger, which first surveyed the trench in 1951.
[1]The maximum surveyed depth of the Challenger Deep is 10,923 meters (35,838 feet) or 6.7875 miles. (National Geographic puts the depth at 10,920.07 meters (35,827 feet) below sea level.) The pressure at this depth is approximately 1,095 times that at the surface, or over 16,000 pounds per square inch (110 MPa).[2]
The HMS Challenger Expedition (December 1872 – May 1876) first sounded the depths now known as the Challenger Deep. This first sounding was made on 23 March, 1875 at station 225. The reported depth was 4,475 fathoms (8,184 m, 26,850 ft), based on two separate soundings.
A 1912 book, The Depths of the Ocean by Sir John Murray, records the depth of the Challenger Deep as 9,635.9472 meters (31,614 feet). Sir John was one of the Expedition scientists, a young man at the time. Page 131 of Murray's book refers to the Challenger Deep. All of the original reports of the Challenger expedition can be viewed on the web at the Challenger Library.
