Pacific Ocean

Photo Courtesy of CIA World Factbook

The Pacific Ocean (from the Latin name Mare Pacificum, "peaceful sea", bestowed upon it by the Portuguese explorer Ferdinand Magellan) is the world's largest body of water. It encompasses a third of the Earth's surface, having an area of 179.7 million km² (69.4 million sq miles). Extending approximately 15,500 km (9,600 miles) from the Bering Sea in the Arctic to the icy margins of Antarctica's Ross Sea in the south (although the Antarctic regions of the Pacific are sometimes described as part of the circumpolar Southern Ocean)the Pacific reaches its greatest east-west width at about 5°N latitude, where it stretches approximately 19,800 km (12,300 miles) from Indonesia to the coast of Colombia. The western limit of the ocean is often placed at the Strait of Malacca. The lowest point on earth—the Mariana Trench—lies some 10,911 m (35,797 ft) below sea level.

The Pacific contains about 25,000 islands (more than the total number in the rest of the world's oceans combined), the majority of which are found south of the equator.

Along the Pacific Ocean's irregular western margins lie many seas, the largest of which are the Celebes Sea, Coral Sea, East China Sea, Sea of Japan, South China Sea, Sulu Sea, Tasman Sea, and Yellow Sea. The Straits of Malacca joins the Pacific and the Indian Oceans on the west, and the Straits of Magellan links the Pacific with the Atlantic Ocean on the east.

As the Pacific straddles the ±180° longitude where East becomes West, the Asian side of the ocean (where latitudes are E) is correctly referred to as East Pacific and the opposite side (eastwards) where latitudes are W is the West Pacific. To retain the popular "left is western" and "right is eastern" means of reference, the Western Pacific is thus the East Pacific and the Eastern Pacific the West Pacific. The International Date Line follows the ±180° longitude to the greater part of its North-South demarcation but veers far eastwards around Kiribati (Caroline Island, which, not coincidentally, was renamed Millennium Island) and westwards round the Aleutian Islands as can be seen on the map at International Date Line.

For most of Ferdinand Magellan's voyage from the Straits of Magellan to the Philippines, the Portuguese explorer indeed found the ocean peaceful. However, the Pacific is not always peaceful. Many typhoons and hurricanes batter the islands of the Pacific and the lands around the Pacific rim are full of volcanoes and often rocked by earthquakes. Tsunamis, caused by underwater earthquakes, have devastated many islands and wiped out whole towns.

The ocean floor of the central Pacific basin is relatively uniform, an abyssal plain with a mean depth of about 4270 m (14,000 ft). The major irregularities in the basin are the extremely steep-sided, flat-topped submarine peaks known as seamounts. The western part of the floor consists of mountain arcs that rise above the sea as island groups, such as the Solomon Islands and New Zealand, and deep oceanic trenches, such as the Mariana Trench, the Philippine Trench, and the Tonga Trench. Most of the trenches lie adjacent to the outer margins of the wide western Pacific continental shelf.