Rangitoto Island

Rangitoto Island is a volcanic island in the Hauraki Gulf near Auckland, New Zealand. The 5.5 km wide island is an iconic and widely visible landmark of Auckland with its distinctive symmetrical shield volcano cone rising 260 metre (850 ft) high over the Hauraki Gulf. [ [http://www.volcano.si.edu/world/tpgallery.cfm?category=Shield%20Volcanoes Shield volcanoes] (from the lobal Volcanism Program website, Smithsonian Institution. Accessed 2008-06-21.)] Rangitoto is the most recent and the largest (2311 hectares) of the approximately 50 volcanoes of the Auckland Volcanic Field. It is linked by a natural causeway to the much older, non-volcanic Motutapu Island and is separated from the mainland of Auckland's North Shore by the Rangitoto Channel.

"Rangitoto" is Māori for 'Bloody Sky', [http://www.gns.cri.nz/what/earthact/volcanoes/arc/rang.html What happened to local Maori?] (from the Rangitoto page on the GNS Science website)] with the name coming from the full phrase "Ngā Rangi-i-totongia-a Tama-te-kapua" ('The days of the bleeding of Tama-te-kapua'). Tama-te-kapua was the captain of the Arawa "waka" (canoe) and was badly wounded on the island, at a (lost) battle with the Tainui "iwi" (tribe) at Islington Bay.

Geology

Rangitoto was formed by a series of eruptions between 600 and 700 years ago. Scientists are in dispute about the length of the eruptions, which are thought to have lasted (with interruptions) for 10 to 200 years. In any case, the amount of mass that erupted from the volcano was about equal to the combined mass of all other eruptions in the Auckland Volcanic Field before. [http://www.arc.govt.nz/environment/volcanoes-of-auckland/rangitoto.cfm Rangitoto] (from the Auckland Regional Council website)] [http://www.nzgeographic.co.nz/articles.php?ID=75 Rangitoto] (abridged article from New Zealand National Geographic)]

The volcano is not expected to become active again, although future eruptions are likely within the volcanic field. Subsiding matter during the cooling process has left a moat-like ring around the crater summit, which may be viewed from a path which goes right round the rim and up to the highest point. [http://www.aucklandcity.govt.nz/auckland/introduction/hauraki/default.asp Hauraki Gulf Islands - Rangitoto Island] (from the Auckland City Council website)]

The island is considered especially significant because all stages from raw lava fields to scrub establishment and sparse forests are visible. In some parts of the island, fields of lightweight, clinker-like black lava stones are still exposed, appearing very recent to a casual eye. Visitors walk through the lava fields and may also walk through some of about seven known lava caves — tubes left behind after the passage of liquid lava. The more accessible of the caves are signposted.

History

Māori association

The volcano erupted within the historical memory of the local Māori iwi (tribes). [http://www.nzgeographic.co.nz/articles.php?ID=75 Rangitoto] (abridged article from New Zealand National Geographic)] Human footprints have been found between layers of Rangitoto volcanic ash on the adjoining Motutapu Island. Ngāi Tai was the iwi living on Motutapu, and considers both islands their ancestral home. Ngāti Paoa also has links with Rangitoto. [cite book|title=Natural History of Rangitoto Island|author=Mike D Wilcox and others|id=ISBN 978-0-9583447-3-9|pages=16|year=2007|publisher=Auckland Botanical Society]

A number of Māori myths exist surrounding the island, including that of a 'tupua' couple, children of the Fire Gods. After quarreling and cursing Mahuika, the fire-goddess, their home on the mainland was destroyed by Mataoho, god of earthquakes and eruptions on Mahuika's behalf. Lake Pupuke in North Shore City was created in the destruction, while Rangitoto rose from the sea. The mists surrounding Rangitoto at certain times are considered the tears of the tupua for their former home.

ince European colonisation

The island was purchased by the Crown in 1854, a very early date in New Zealand's colonisation by Europeans, and set aside as a recreation reserve in 1890. Nonetheless, for over 30 years, scoria was quarried from the volcano as building material for Auckland. From 1925 to 1936, prison labour built roads on the island and a track to the summit.

Military installations were built during World War II to support the Auckland harbour defences and to house U.S. troops or store mines. The most visited remains of these installations is the old observation post on the summit. The northern shore of the island was used as a wrecking ground for unwanted ships, and the remains of several wrecks are still visible at low tide. [cite web|url=http://www.arc.govt.nz/heritage/maritime-heritage/rangitoto-ships-graveyard/rangitoto-ships-graveyard_home.cfm|title=Rangitoto Ships' Graveyard|publisher=Auckland Regional Council website|accessdate=2008-06-08 ]

Baches (small holiday houses) were built around the island's edge in the 1920s and 1930s. The legality of their existence was doubtful from the start and the building of further baches was banned in 1937. Most have since been removed because of the ban and because the island has become a scenic reserve. However some of the 140 baches are being preserved to show how the island used to be, once boasting a permanent community of several hundred people, including a good number of children. The buildings included some more permanent structures like a seawater pool built of quarried stones by convict labour, located close to the current ferry quay. [ [http://www.rangitoto.org/ Welcome to Rangitoto Island] (from the Rangitoto Island Historic Conservation Trust)]

There are now daily ferry trips to the island from Auckland but overnight stays are not generally possible, though a campsite exists. A day trip allows plenty of time for the fit to walk to the summit and back, with stunning views of the harbour and city. An alternative to walking, a land train, co-ordinated with the ferry sailings, takes visitors to a short way below the summit. [http://www.fullers.co.nz/index.php/ps_pagename/rangitotoisland1 Rangitoto Island - Unique Volcanic Island] (from the Fullers ferry operator website)]

Biology

There are virtually no streams on the island so plants rely on rainfall for moisture. It has the largest forest of pōhutukawa trees in the world, as well as many northern rātā trees. In total, more than 200 species of trees and flowers thrive on the island, including several species of orchid, as well as more than 40 types of fern.

As lava fields contain no soil of the typical kind, windblown matter and slow breaking-down processes of the native flora are still in the process of transforming the island into a more habitable area for most plants, which is one of the reasons why the local forests are relatively young and do not yet support a large bird population. However, the kākā, a New Zealand-endemic parrot, is thought to have lived on the island in pre-European times.

Goats were present on Rangitoto in large numbers in the mid 19th century, but were eradicated in the 1880s. Fallow deer were introduced to Motutapu in 1862 and spread to Rangitoto, but disappeared by the 1980s. The brush-tailed rock-wallaby was introduced to Motutapu in 1873, and was common on Rangitoto by 1912, and the brushtail possum was introduced in 1931 and again in 1946. Both were eradicated in a campaign from 1990 to 1996 using 1080 and cyanide poison and dogs. Stoats, rabbits, mice, rats, cats and hedgehogs remain a problem, [cite book|title=Natural History of Rangitoto Island|author=Mike D Wilcox and others|id=ISBN 978-0-9583447-3-9|pages=23-24|year=2007|publisher=Auckland Botanical Society] but the Department of Conservation (DOC) aims to eradicate them in the next few years, beginning with the poisoning of black rats, brown rats and mice. [ [http://www.doc.govt.nz/templates/page.aspx?id=44487 Rangitoto & Motutapu pest eradication project] , Department of Conservation.] [ [http://www.doc.govt.nz/templates/page.aspx?id=45332 Rangitoto & Motutapu rodent eradication] , Department of Conservation.] As the area is a DOC-administered reserve (in partnership with the 'tangata whenua' Ngāi Tai and Ngāti Paoa), visitors may not take dogs or other animals onto the islands.

ee also

* Volcanoes in New Zealand

References

External links

* [http://www.doc.govt.nz/templates/PlaceProfile.aspx?id=34262 Rangitoto Island Scenic Reserve] (from the DOC website)
* [http://www.peakbagging.co.nz/index.php/Rangitoto Walking up Rangitoto] from peakbagging.co.nz
* Julian, Andrea (1992) [http://hdl.handle.net/2292/27 The vegetation pattern of Rangitoto] University of Auckland PhD Thesis
*Whiting, Diana (1986) [http://hdl.handle.net/2292/389 Vegetation colonisation of Rangitoto Island: the role of crevice microclimate] University of Auckland Masters Thesis