Borders of the oceans

The borders of the oceans are the limits of the Earth's oceanic waters. The definition and number of oceans can vary depending on the adopted criteria.

Overview

Though generally described as several separate oceans, the world's oceanic waters constitute one global, interconnected body of salt water sometimes referred to as the World Ocean or global ocean. This concept of a continuous body of water with relatively free interchange among its parts is of fundamental importance to oceanography.

The major oceanic divisions are defined in part by the continents, various archipelagos, and other criteria. The principal divisions (in descending order of area) are the: Pacific Ocean, Atlantic Ocean, Indian Ocean, Arctic Ocean, and Southern (Antarctic) Ocean. Smaller regions of the oceans are called seas, gulfs, bays, straits, and other names.

Geologically, an ocean is an area of oceanic crust covered by water. Oceanic crust is the thin layer of solidified volcanic basalt that covers the Earth's mantle. Continental crust is thicker but less dense. From this perspective, the earth has three oceans: the World Ocean, the Caspian Sea, and Black Sea. The latter two were formed by the collision of Cimmeria with Laurasia. The Mediterranean Sea is at times a discrete ocean, because tectonic plate movement has repeatedly broken its connection to the World Ocean through the Strait of Gibraltar. The Black Sea is connected to the Mediterranean through the Bosporus, but the Bosporus is a natural canal cut through continental rock some 7,000 years ago, rather than a piece of oceanic sea floor like the Strait of Gibraltar.

Ocean

An ocean (from Ancient Greek Ὠκεανός, transc. Okeanós, the sea of classical antiquity) is a body of saline water that composes much of a planet's hydrosphere. On Earth, an ocean is one of the major conventional divisions of the World Ocean, which covers almost 71% of its surface. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern, and Arctic Oceans. The word sea is often used interchangeably with "ocean" in American English but, strictly speaking, a sea is a body of saline water (generally a division of the world ocean) partly or fully enclosed by land.

Saline water covers approximately 72% of the planet's surface (~3.6×10⁸ km²) and is customarily divided into several principal oceans and smaller seas, with the ocean covering approximately 71% of Earth's surface. The ocean contains 97% of Earth's water, and oceanographers have stated that less than 5% of the World Ocean has been explored. The total volume is approximately 1.35 billion cubic kilometers (320 million cu mi) with an average depth of nearly 3,700 meters (12,100 ft).

Hillsong United (band)

The Hillsong United band (stylised as Hillsong UNITED or UNITED) is a worship band that originated as a part of Hillsong Church. Formed in 1998 as part of Hillsong's youth ministry, the band consists of several rotating worship leaders from the church, including Brooke Fraser, Joel Houston, Reuben Morgan and Marty Sampson. Due to several songs written by the youth ministry, Hillsong worship leader Darlene Zschech recommended that they record an album, which resulted in their debut extended play, One, which was released alongside the Hillsong Worship album Touching Heaven Changing Earth. Since then, the group has released eleven annual live albums, as well as four studio albums. The band composes songs and performs in church services as well as concerts in worldwide tours.

History

The band was originally formed in 1998, by close friends from within the youth ministry called "Powerhouse Youth", led by Hillsong Youth Pastors Phil and Lucinda Dooley for many years. As the house band for the Powerhouse meetings, they played original songs and rearranged popular radio tunes at their weekly meeting for local youth aged 16–25. Band members sometimes also contributed to the larger interdenominational ministry Youth Alive Australia and its albums. Most members of the band also attended Hillsong Church services.

Indian Ocean

The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded by Asia on the north, on the west by Africa, on the east by Australia, and on the south by the Southern Ocean or, depending on definition, by Antarctica. It is named after India. The Indian Ocean is known as Ratnākara (Sanskrit: रत्नाकर), "the mine of gems", in ancient Sanskrit literature and as Hind Mahāsāgar (Devanāgarī: हिन्द महासागर) in Hindi.

Geography

The borders of the Indian Ocean, as delineated by the International Hydrographic Organization in 1953 included the Southern Ocean but not the marginal seas along the northern rim, but in 2000 the IHO delimited the Southern Ocean separately, which removed waters south of 60°S from the Indian Ocean, but included the northern marginal seas.Meridionally, the Indian Ocean is delimited from the Atlantic Ocean by the 20° east meridian, running south from Cape Agulhas, and from the Pacific Ocean by the meridian of 146°55'E, running south from the southernmost point of Tasmania. The northernmost extent of the Indian Ocean is approximately 30° north in the Persian Gulf.

Atlantic Ocean

The Atlantic Ocean is the second largest of the world's oceanic divisions, following the Pacific Ocean. With a total area of about 106,400,000 square kilometres (41,100,000 sq mi), it covers approximately 20 percent of the Earth's surface and about 29 percent of its water surface area. The first part of its name refers to Atlas of Greek mythology, making the Atlantic the "Sea of Atlas".

The oldest known mention of "Atlantic" is in The Histories of Herodotus around 450 BC (Hdt. 1.202.4): Atlantis thalassa (Greek: Ἀτλαντὶς θάλασσα; English: Sea of Atlas). The term Ethiopic Ocean, derived from Ethiopia, was applied to the southern Atlantic as late as the mid-19th century. Before Europeans discovered other oceans, their term "ocean" was synonymous with the waters beyond the Strait of Gibraltar that are now known as the Atlantic. The early Greeks believed this ocean to be a gigantic river encircling the world.

The Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Eurasia and Africa to the east, and the Americas to the west. As one component of the interconnected global ocean, it is connected in the north to the Arctic Ocean, to the Pacific Ocean in the southwest, the Indian Ocean in the southeast, and the Southern Ocean in the south (other definitions describe the Atlantic as extending southward to Antarctica). The equator subdivides it into the North Atlantic Ocean and South Atlantic Ocean.