Saturday, August 25, 2012

Determining Ocean Depths and Various Water Levels Using Sonar

Ocean depths and water levels are most of the time difficult to determine. This is because there are various complications that can occur if any other means are used to measure the depth other than sonar. Complications could include high water pressure, pitch black darkness, shifting sea floor and many others. SONAR stands for Sound Navigation and Ranging and it uses short bursts of sounds and advance computer processing that will simulate “echo-location,” which marine mammals like whales and dolphins use to navigate deep waters.

Different Ocean Depths
Deep seas are classified into five different levels and these are called “Epipelagic,” which is primarily the ocean surface or about 0 – 650 feet (0 – 200 meters), “Mesopelagic,” which has a depth of 650 – 3,300 feet (200 – 1,000 meters), “Bathypelagic,” which is the third deepest level of the ocean having a depth of 1,000 – 4,000 meters or 3,300 – 13,000 feet. The area closer to the ocean floor is called “Abyssopelagic” and it’s between 13,000 to 20,000 feet (4,000 – 6,000 meters). The deepest places in the ocean are called “Hadopelagic” and they can reach as deep as 10,000 meters or 35,000 feet, where the crushing depth and pressure could reach as much as 15,750 pounds per square inch!

The use of SONAR in marine and submarine navigation has been proven to be a very effective tool in both maritime and military aspects (particularly the navy and other oceanographic research vessels). Like in aviation with the use of RADAR (Radio Detection And Ranging), SONAR allows ships to detect objects underneath the ocean where they navigate and determine their size as well as their relative distance, bearing and depth. The USS Los Angeles (SSN-688) submarine for instance has sophisticated sensitive skin that can detect and identify other vessels as well as different animal life under water. Its computer can differentiate a whale from an enemy submarine or vessel. Its advanced SONAR systems allows it to venture in traditionally considered “difficult” waters, despite its size of 361 feet and 11 inches long, 32 feet and 10 inches wide, and 6,072 tons at full capacity. Meanwhile vessels employs both RADAR and SONAR. For example fishermen use GPS (global positioning satellites) to locate schools of fish, SONAR for navigation and also to locate schools of fish in the immediate vicinity, and RADAR to detect other ships and to avoid mid-ocean collisions.

It was the sinking of the Titanic that prompted the invention of SONAR and indeed after 1913 there were no more ocean disasters that could match that of the famed British vessel. However, in the 1970’s scientists figured that they can use SONAR to map the vast ocean floor, especially since no one knew how deep the ocean was before that time. They used dynamite and SONAR to pick up the echoes from the ocean floor as they traveled the Atlantic and the Pacific Ocean and was able to give us a 80 – 90% accurate map of the ocean floor.

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