Editing South Island (section)

===Natural geographic features===

====Fiords====
{{Main|Fiords of New Zealand}}

[[File:00 1371 New Zealand - Milford Sound.jpg|thumb|Typical view of [[Milford Sound / Piopiotahi]] featuring [[Mount Pembroke]]]]
[[File:A View from the Top (Unsplash).jpg|thumb|[[Fiordland National Park]]]]

The South Island has 15 named maritime [[fjord|fiords]] which are all located in the southwest of the island in a mountainous area known as [[Fiordland]]. The spelling 'fiord' is used in New Zealand rather than 'fjord', although all the maritime fiords use the word [[Sound (geography)|Sound]] in their name instead.

A number of lakes in the Fiordland and [[Otago]] regions also fill [[glacial valley]]s. [[Lake Te Anau]] has three western arms, which are fiords (and are named so). [[Lake McKerrow / Whakatipu Waitai]] to the north of [[Milford Sound / Piopiotahi]] is a fiord with a silted-up mouth. [[Lake Wakatipu]] fills a large glacial valley, as do lakes [[Lake Hakapoua|Hakapoua]], [[Lake Poteriteri|Poteriteri]], [[Lake Monowai|Monowai]] and [[Lake Hauroko|Hauroko]] in the far south of Fiordland. [[Lake Manapouri]] has fiords as its west, north and south arms.

The [[Marlborough Sounds]], a series of deep indentations in the coastline at the northern tip of the South Island, are in fact [[ria]]s, drowned river valleys.

====Glaciers====
{{Main|Glaciers of New Zealand}}

[[File:Franz Josef glacier.JPG|right|thumb|[[Franz Josef Glacier]]]]

Most of New Zealand's [[glacier]]s are in the South Island. They are generally found in the [[Southern Alps]] near the Main Divide.

An inventory of South Island glaciers during the 1980s indicated there were about 3,155 glaciers with an area of at least {{convert|1|ha|spell=in}}.<ref>Chinn, Trevor J.H., (1988), [http://pubs.usgs.gov/prof/p1386h/nzealand/nzealand.html Glaciers of New Zealand], in ''Satellite image atlas of glaciers of the world'', U.S. Geological Survey professional paper; 1386, {{ISBN|978-0-607-71457-9}}.</ref> About a sixth of these glaciers covered more than 10&nbsp;hectares. These include the [[Fox Glacier|Fox]] and [[Franz Josef Glacier|Franz Josef]] glaciers on the West Coast, and the [[Tasman Glacier|Haupapa / Tasman]], [[Hooker Glacier (New Zealand)|Hooker]], [[Mueller Glacier|Mueller]] and [[Murchison Glacier|Murchison]] glaciers in the east.

====Lakes====
{{Main|Lakes of New Zealand}}

[[File:Lake hauroko.jpg|right|thumb|[[Lake Hauroko]]]]

There are some 3,820 lakes in New Zealand with a [[surface area]] larger than one hectare. Much of the higher country in the South Island was covered by ice during the [[glacial period]]s of the last two million years. Advancing glaciers eroded large steep-sided valleys, and often carried piles of [[moraine]] (rocks and soil) that acted as natural dams. When the glaciers retreated, they left basins that are now filled by lakes. The level of most glacial lakes in the upper parts of the [[Waitaki River|Waitaki]] and [[Clutha River / Mata-Au|Clutha / Mata-Au]] rivers are controlled for electricity generation. Hydroelectric reservoirs are common in [[South Canterbury]] and [[Central Otago]], the largest of which is [[Lake Benmore]], on the [[Waitaki River]].

The South Island has 8 of New Zealand's 10 biggest lakes. They were formed by [[glaciers]] and include [[Lake Wakatipu]], [[Lake Tekapo]] and [[Lake Manapouri]]. The deepest (462&nbsp;m) is [[Lake Hauroko]], in western [[Southland, New Zealand|Southland]]. It is the 16th deepest lake in the world. Millions of years ago, [[Central Otago]] had a huge lake – [[Lake Manuherikia]]. It was slowly filled in with mud, and [[fossil]]s of fish and crocodiles have been found there.

====Volcanoes====
{{Main|Volcanoes in New Zealand}}

[[File:Banks Peninsula from space.jpg|thumb|right|[[Banks Peninsula]] is roughly circular, with many bays and two deep harbours]]
There are four [[extinct]] volcanoes in the South Island, all located on the east coast.

[[Banks Peninsula]] forms the most prominent of these volcanic features. Geologically, the peninsula comprises the eroded remnants of two large [[shield volcano]]es (Lyttelton formed first, then Akaroa). These formed due to intraplate volcanism between about eleven and eight million years ago ([[Miocene]]) on a continental crust. The peninsula formed as offshore islands, with the volcanoes reaching to about 1,500&nbsp;m above sea level. Two dominant craters formed [[Lyttelton Harbour / Whakaraupō|Lyttelton / Whakaraupō]] and [[Akaroa Harbour|Akaroa]] Harbours.

The [[Canterbury Plains]] formed from the erosion of the [[Southern Alps]] (an extensive and high mountain range caused by the meeting of the [[Indo-Australian Plate|Indo-Australian]] and [[Pacific Plate|Pacific tectonic plates]]) and from the [[alluvial fan]]s created by large [[braided river]]s. These plains reach their widest point where they meet the hilly sub-region of Banks Peninsula. A layer of [[loess]], a rather unstable fine silt deposited by the [[foehn wind]]s which bluster across the plains, covers the northern and western flanks of the peninsula. The portion of the crater rim lying between Lyttelton Harbour / Whakaraupō and Christchurch city forms the [[Port Hills]].

The [[Otago Harbour]] was formed from the drowned remnants of a giant [[shield volcano]], centred close to what is now the town of [[Port Chalmers]]. The remains of this violent origin can be seen in the [[basalt]] of the surrounding hills. The last eruptive phase ended some ten million years ago, leaving the prominent peak of [[Mount Cargill]].

[[Timaru]] was constructed on rolling hills created from the lava flows of the extinct Mount Horrible, which last erupted many thousands of years ago.

====Te Wāhipounamu World Heritage Site====

'''[[Te Wahipounamu|Te Wāhipounamu]]''' ([[Māori language|Māori]] for "the place of [[Pounamu|greenstone]]") is a [[World Heritage Site]] in the south-west corner of the South Island.<ref>{{cite web |url=https://whc.unesco.org/en/list/551 |title=UNESCO World Heritage official website listing }}</ref>

Inscribed on the World Heritage List in 1990, it covers {{convert|26000|km2}} and incorporates the [[Aoraki / Mount Cook National Park|Aoraki / Mount Cook]], the [[Fiordland National Park|Fiordland]], the [[Mount Aspiring National Park|Mount Aspiring]] and the [[Westland Tai Poutini National Park|Westland Tai Poutini]] National Parks.

It is thought to contain some of the best modern representations of the original [[flora]] and [[fauna]] present in [[Gondwanaland]], one of the reasons for listing as a World Heritage Site.