Location: Mariana Trench (Subduction Boundary)

The third location I visited was the Mariana Trench. It is the deepest part of the ocean in the world. The longitude and latitude points were  11°19'0.01"N 142°14'59.96"E. It is located in the Western Pacific Ocean, as shown in the picture. It is also the deepest part of the ocean. This trench is formed by a subduction boundary. A subduction boundary is when a ocean plate plunges beneath another plate. A long deep trench called a deap-sea trench forms along the boundary. Such trenches are the deepest part of the ocean floor. When two oceanic plates converge, the deep-sea trench that forms is accompanied by the formation of a chain of volcanic islands called a volcanic island arc on the overriding plate. In this case, as the Pacific Plate sub ducts under the Philippine Plate, the Pacific Plate is pulled down to form the Mariana Trench. The leading edge of the overriding Philippine Plate is marked by a chain of volcanic islands, the Mariana Islands. Four descents have been achieved as of today to Challenger Deep, the deepest part of the trench.

http://upload.wikimedia.org/wikipedia/commons/1/1b/Marianatrenchmap.png