TheTasman Sea is amarginal sea of theSouth Pacific Ocean, situated betweenAustralia andNew Zealand. It measures about 2,000 km (1,200 mi) across and about 2,800 km (1,700 mi) from north to south. The sea was named after the Dutch explorerAbel Janszoon Tasman, who in 1642 was the first known European to cross it. British explorer LieutenantJames Cook later extensively navigated the Tasman Sea in the 1770s during his three voyages of exploration.[1]
TheMāori people of New Zealand call this seaTe Moana-a-Rehua meaning 'the sea of Rehua' which clashes with the Pacific waters namedTe Tai-o-Whitirea ('the sea of Whitirea') – after Whitirea, Rehua's lover – atCape Reinga, the northernmost tip ofNorth Island.[2]
The south of the sea is passed over by depressions going from west to east. The northern limit of these westerly winds is near to40°S. During the southern winter, from April to October, the northern branch of these winds from the west changes its direction toward the north and goes up againsttrade winds. Hence, the sea receives frequent winds from the southwest during this period. In the Australian summer (from November to March), the southern branch of the trade winds goes up against west winds and produces further wind activity in the area.[3]
The Tasman Sea is 2,250 km (1,400 mi) wide and has an area of 2,300,000 km2 (890,000 sq mi).[1] The maximum depth of the sea is 5,943 m (19,498 ft).[4] The base of the sea is made up ofglobigerina ooze. A small zone of pteropod ooze is found to the south ofNew Caledonia and to the southern extent of30°S,siliceous ooze can be found.[5]
On the West A line fromGabo Island (nearCape Howe, 37°30'S) to the northeast point of East Sister Island (148°E), thence along the148th meridian toFlinders Island; beyond this island a line running to the eastward of the Vansittart Shoals to [Cape]Barren Island, and from Cape Barren (the easternmost point of [Cape] Barren Island) to Eddystone Point (41°S) in Tasmania, thence along the east coast toSouth East Cape, the southern point of Tasmania.
The Tasman Sea'smidocean ridge developed between 85 and 55 million years ago as Australia andZealandia broke apart during the breakup ofsupercontinentGondwana. It lies roughly midway between the continental margins of Australia and Zealandia. Much of Zealandia is submerged, so the ridge runs much closer to the Australian coast than New Zealand's.[7]
TheEast Australian Current that commences its flow southwards in the tropics of the Coral Sea, near the eastern coast of Australia is the most energetic circulation feature in the south western Pacific Ocean and is a primary means of heat transport from the tropics to the middle latitudes between Australia and New Zealand.[12]: 1458 The East Australian Current is a return of the westward-flowing Pacific Equatorial Current (PacificSouth Equatorial Current).[13] At the juncture between the Tasman and Coral seas while the East Australian Current continues south in the western Tasman a branch flows east called theTasman Front towards the north of New Zealand with most continuing eastward above New Zealand into the South Pacific Ocean.[13] It transpires that while predominantly the location of westerly wind stress is a factor in how far north the formation of the Tasman Front occurs, so is the presence of the New Zealand land mass, as the top of New Zealand defines the furtherest south that the Tasman Front can be split off by the westerly winds.[12]: 1457, 1467–8 A boundary current called the East Auckland Current goes down the west coast of the North Island and further south the East Cape Current, that has been diverted towards the South Island by the shapes of the Lord Howe Rise and southern east coast of the North island continues to the south.[12]: 1458 [13] The East Australian Current south of Tasmania also is diverted west in the Subtropical Front which collides with the western moving Subantarctic front of theAntarctic Circumpolar Current.[13] The East Australian Current sheds eddies on its way south that move south-westward with some known as the Tasman Leakage making it as far westward as the Indian Ocean.[12]: 1458
A deep-sea research ship, theRVTangaroa, explored the sea and found 500 species of fish and 1300 species of invertebrates. The tooth of amegalodon, an extinct shark, was also found by researchers.[14]
In 1876, the firsttelegraph cable connecting Australia and New Zealand was laid in the Tasman Sea.[15] The telegraph cable was made obsolete in 1963 when theCommonwealth Pacific Cable, New Zealand's first international telephone cable, was completed.[16]Moncrieff and Hood were the first to attempt atrans-Tasman crossing by plane in January 1928. The aviators were never seen or heard of again. The first successful flight over the sea was accomplished byCharles Kingsford Smith andCharles Ulm later that year. The first person to row solo across the sea wasColin Quincey in 1977. The next successful solo crossing was completed by his son, Shaun Quincey, in 2010.[17]
The Tasman Sea has for many years been referred tocolloquially as "The Ditch" by Australians and New Zealanders. The exact etymology for this term is uncertain.[18]
