Panama Canal - geography.

Panama Canal - geography. I INTRODUCTION Panama Canal The Panama Canal consists of three separate canal locks, as well as other artificial waterways. The canal spans a total distance of 64 km (40 mi) from the Pacific Ocean to the Atlantic Ocean through the Isthmus of Panama. The ship shown here is entering the Panama Canal from the Caribbean, or Atlantic, side. Will and Deni McIntyre/Photo Researchers, Inc. - geography. Panama Canal, canal across the Isthmus of Panama, in Central America, that allows vessels to travel between the Pacific and Atlantic oceans. The waterway measures 64 km (40 mi), including dredged approach channels at each end. The Panama Canal handles a large volume of world shipping and enables vessels to avoid traveling around South America, reducing their voyages by thousands of miles and many days. The canal consists of artificially created lakes, channels, and a series of locks, or water-filled chambers, that raise and lower ships through the mountainous terrain of central Panama. Built by the United States from 1904 to 1914, the Panama Canal posed major engineering challenges, such as damming a major river and digging a channel through a mountain ridge. It was the largest and most complex project of this kind ever undertaken at that time, employing tens of thousands of workers and costing $350 million. The canal cuts through the central and most populated region of Panama, and it has been a point of dispute between the governments of Panama and the United States through most of its existence. Under a 1903 treaty, the United States controlled both the waterway and a large section of the surrounding land, known as the Panama Canal Zone, as if they were U.S. territory. Panamanians resented this arrangement and argued that their country was unfairly denied benefits from the canal. Eventually, riots and international pressure led the United States to negotiate two new treaties, which were signed in 1977 and took effect in 1979. The treaties recognized Panama's ultimate ownership of the canal and all the surrounding lands. More than half of the former Canal Zone came under Panamanian control shortly after the treaties were ratified. Control of the canal was turned over to Panama on December 31, 1999. II TRAVELING THROUGH THE CANAL Panama Canal Cross Section This cross section shows the route of a ship through the Panama Canal. From the Atlantic Ocean, a ship is raised 26 m (85 ft) through three sets of locks to the level of Gatún Lake. It travels through the lake and Gaillard Cut, the narrowest section of the canal. It is then lowered through a lock to Miraflores Lake, and passes through two more locks before reaching the Pacific Ocean. © Microsoft Corporation. All Rights Reserved. The canal consists of dredged approaches and three sets of locks at each end; Gatún Lake, one of the largest artificially created bodies of water in the world; and the excavated portion of the crossing, called Gaillard Cut. At Gatún, on the Atlantic side, the locks form continuous steps; on the Pacific side, a small lake (Miraflores) separates the middle and upper locks. Because the Isthmus of Panama extends east-west, a ship sailing from the Atlantic to the Pacific through the canal actually travels from northwest to southeast. To travel from the Atlantic to the Pacific, a ship enters Limón Bay from the north and anchors behind a breakwater to await scheduling of its passage. When ready, the canal authorities send out a canal pilot to take the vessel through the locks. The canal employs about 240 highly trained and experienced pilots to handle the complex job of steering ships through the waterway. As soon as the pilot takes over, the ship is under canal jurisdiction. Very large or hard-to-maneuver ships may require two or more pilots and assistance from tugboats. The ship travels south-southeast about 11 km (7 mi) and enters the first lock at Gatún. Line handlers at the lock attach steel mooring cables that are controlled by powerful electric locomotives, called mules. The mules guide the ship through the locks and steady it while the chambers are filled with water. In three steps the ship is raised to the level of Gatún Lake, 26 m (85 ft) above the sea. Lock A lock is a section of a waterway enclosed by gates at either end to allow ships to be raised or lowered to a different water level. In this example, a ship enters the upper level and the gates close behind it. The water is then allowed to drain into the lower level, lowering the water level of the lock and the ship. When the water level of the lock equals the level of the lower canal, the lower gates will open and the ship can proceed. © Microsoft Corporation. All Rights Reserved. The canal's 12 locks (3 ...