Page 482 - (DK) Ocean - The Definitive Visual Guide

480 THE PACIFIC OCEAN A B

150˚E
Southeast Australia PACIFIC OCEAN B6 Coral Sea Islands Mellish
Bass Strait Rise
and New Zealand LENGTH 400km (250 miles) 1

MINIMUM WIDTH 100km (62 miles) Coral Sea
TO THE NORTHEAST OF AUSTRALIA, ocean currents flow from
the east, feeding the warm East Australia Current, which sweeps The Bass Strait separates Tasmania
from Australia, overlying a shallow 20˚S
south along the Australian coast, before turning east to flow north shelf around 50m (160ft) deep. Strong Great Barrier Reef
of New Zealand. South of New Zealand, the Antarctic Circumpolar winds and currents from the Southern Mackay
Current flows from west to east. New Zealand straddles a major Ocean combine with the shallow depth
to make its waters notoriously rough.
tectonic boundary between the Pacific and Australian plates.
Hundreds of ships were wrecked on its
2
shores during the 19th century, before
motion yet. The older oceanic crust of the erection of lighthouses made
PACIFIC OCEAN G4 Tropic of Capricorn
the Pacific Plate is sinking below the navigation safer. Natural gas fields
Kermadec–Tonga more buoyant crust of the young were discovered beneath the eastern Fraser
oceanic Australian Plate. The Tonga Bass Strait in the 1960s and 1990s. Island
Trench Ridge and the older Lau Ridge
formed as arcs of volcanoes. The rapid
LENGTH 2,500km (1,550 miles)
motion has caused extension of the Brisbane
DEPTH 10,800m (35,430ft) Australian Plate and the opening of a Gold
RATE OF CLOSURE 15–24cm (6–9in) per year back-arc basin between the two ridges, Coast
in the Lau Basin. The latest addition to
The Kermadec–Tonga Trench runs this island chain is new land at the
between the North Island of New southern end of Hunga Ha’apai that
Zealand and the island of Tonga. emerged in 2009 after several undersea
The Pacific Plate converges with the volcanic eruptions. Together with Fiji
Australian Plate in this suduction zone. and Samoa, the 36 islands of Tonga are
At its northern end, closure rates of the cradle of the Polynesian seafaring 30˚S
24cm (9in) per year have been culture, which had stretched across the AUSTRALIA
measured – the fastest recorded plate South Pacific by the 12th century. PHILLIP ISLAND
Newcastle
4
PACIFIC OCEAN C5 PACIFIC OCEAN H3 Sydney
Tasman Sea Southwest Pacific Wollongong
AREA 2.3 million square km (890,000 square miles) Basin
MAXIMUM DEPTH 5,945m (19,500ft) Tasman Plain
AREA 23 million square km (8.9 million square miles)
INFLOWS Southern Ocean, Coral Sea
MAXIMUM DEPTH 5,655m (18,500ft)
This warm sea was discovered by INFLOWS Pacific Ocean, Southern Ocean
Dutch explorer Abel Tasman in 1642, 5 Cape
while looking for Terra Australis (the The Southwest Pacific Basin lies east Everard
Melbourne
Southern Land). On this voyage he of New Zealand and the Kermadec– 2,620m
become the first European to reach Tonga Trench. It is bounded in the east (8,596ft)
the islands of Tasmania, New Zealand, by the East Pacific Rise (see p.478), South East Point
Tonga, and Fiji. The area was not in the south by the Pacific–Antarctic Cape Otway Furneaux
visited again until James Cook’s voyage Rise, and in the north by the Bass Strait Group
in 1768. On a later voyage, in 1644, Polynesian island chains. The Louisville
King
Tasman succeeded in finding the Ridge is the only significant chain of 40˚S Island
LORD HOWE ISLAND continent of Australia. The Tasman Sea seamounts and much of the basin floor Tasmania
The warm waters of the East Australia has a subtropical climate in the north, is an abyssal plain. There are extensive 6
Current allow Lord Howe Island to host but the influence of cold sub-Antarctic deposits of manganese in the northern Hobart
the world’s most southerly coral reef. water makes it temperate in the south. and southern parts of the basin. East
3,460m Tasman
(11,352t) Plateau
producing volcanism on
PACIFIC OCEAN E5
North Island, and south
New Zealand as the Macquarie Ridge,
730m
where shallow subduction 140˚E (2,395ft)
has uplifted the Australian
TYPE Micro-continental island group
ATLAS OF THE OCEANS New Zealand separated from Australia 2012, the largest of which 7 50˚S Tasman Fracture Zone
Tasman
Plate. A swarm of
AREA 268,680 square km (103,700 square miles)
Plateau
earthquakes hit the South
NUMBER OF ISLANDS 2 main islands
Island between 2010 and
(700 smaller islands)
killed 185 people and
and Antarctica 80 million years ago,
destroyed the historic
cathedral in Christchurch
and is now positioned at the boundary
between the Pacific and Australian
in 2011. The main islands
of New Zealand are the
plates. The largely transverse Alpine
highest points of an
Fault runs 700km (435 miles) across
extensive area of
the South Island. Crustal compression
and distortion across a 250km-
continental crust that
(155-mile-) wide zone has raised the
includes the Campbell
Southern Alps over 4,000m (13,000ft)
Plateau, Challenger Plateau,
CAMPBELL ISLAND
above sea level. The plate boundary
and Chatham Rise. To the southeast,
The southernmost of New Zealand’s
continues north as the Hikurangi
Campbell Plateau is the world’s largest
subantarctic islands, Campbell Island
Trench, a classic subduction zone
is primarily volcanic in origin.
area of submerged continental crust.
A 140˚E B