The Pacific Ocean

Size and Shape

This is the largest ocean of the world. It has an area of 165, 246, 200 sq km which is about one-third of the earth’s surface area. Thus, this vast ocean has an area which exceeds the total land area of the world. It stretches to over 16,000 km along the equator. It is 14,880 km from Bering-Strait in the north to Cape Adre of Antarctic continent in the south. Its shape is roughly triangular with its apex in the north at the Bering Strait and its base at Antarctic continent. It is bounded on the west by the continents of Asia and Australia along with a chain of intermediate islands, on the east by North and South America and on the south by Antarctica.

Floor

The Pacific is the deepest of all the oceans. Continental shelf is not much developed in this ocean. Only 7% of this ocean is less than 1,000 metre deep. The major portion of the basin has an average depth of about 7,300 metres. The Northern Pacific is the deepest part of the ocean . The average depth of this part is 5,000–6,000 metres. There are several trenches or deeps in this part. Some well-known trenches are Aleutian, Kurile, Japan and Bonin trench. They are 7,000–10,000 metres deep. There are several seam founts, guyots, and islands in the central part. Of these, the Hawaiian ridge is well known. In the south-west portion of the Pacific, there is a large variety of islands, margin al seas, continental shelf and sub-marine trenches. Here, Marina trench is 11,033 metre deep. This is the deepest part of the earth discovered so far. Midanao trench, which is 10,500 metre deep, is also located here.

The south-east Pacific has broad submarine ridges and plateaus. The most important are the Albatross Plateau (3,000–4,000 metres deep) and South-Eastern Pacific Plateau (2,000–4,000) metres deep). Atacama trench other coast of Atacama is 8,000 metres deep. Near the Tonga Island, there is Tonga trench which is 9,000 metres deep.

Islands

This vast ocean has more than 20,000 big and small islands. Bigger islands are located near the continental coasts and are made up of rocks similar to those of the continents. Towards the east are the Aleutian, British Columbia and the Chile Islands. The west coast of this ocean is dotted with Kurile, Japan, Philippines and New Zealand. Islands located in the mid-ocean are coral and volcanic in origin.

Marginal Seas

Most of the marginal seas are along the west coast of the ocean. Some of the important seas on this side are Bering Sea, Sea of Okhotsk, Sea of Japan, East China Sea, South China Sea, Celebes Sea, etc. The eastern coast of the Paciis conspicuous by the absence of marginal seas. Only the Gulf California is worth mentioning.

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