Raoul Island

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Raoul Island
NASA image of Raoul Island
NASA image of Raoul Island
Waters Pacific Ocean
Archipelago Kermadec Islands
Geographical location 29 ° 16 ′  S , 177 ° 56 ′  W Coordinates: 29 ° 16 ′  S , 177 ° 56 ′  W
Location of Raoul Island
length 10.1 km
width 6.7 km
surface 29.38 km²
Highest elevation Moumoukai Peak
516  m
Residents 5 (ward staff)
<1 inh / km²
main place (Raoul Island Station)

Raoul Island (formerly called Sunday Island ) is the largest and - apart from the northeastern side islands Nugent Island and Napier Island - northernmost of the New Zealand Kermadec Islands . It is about 30 km², about ten kilometers long, about six kilometers wide and of volcanic origin.

geography

The anvil-shaped island is located about 1000 kilometers from the New Zealand North Island . The nearest neighboring island, Macauley Island to the south , is about 110 kilometers away.

Raoul Island is the summit of a largely submerged volcanic massif with an extension of around 28 by 20 kilometers, which rises from a depth of around 900 meters. The highest point on the island is the 516 meter high Moumoukai Peak . It is located on the eastern edge of a caldera with a diameter of two to three kilometers, the Raoul Caldera . There are two lakes in the caldera, the Blue Lake in the north and the smaller Green Lake . A second caldera, the Denham Caldera with a length of about 6.5 kilometers and a width of about four kilometers, borders to the west. The caldera is largely below sea level; its northeastern edge is Denham Bay from Raoul Island.

Nautical chart of the island (1887)

The oldest rocks on the island are andesites , which were formed in submarine eruptions 600,000 to 1.4 million years ago. Later a stratovolcano rose above sea level. It collapsed in a powerful eruption , creating a large caldera, which probably also occupied the area of ​​today's two calderas. Subsequent eruptions built new cones. The Raboul Caldera was formed in an eruption about 4000 years ago; the Denham Caldera about 2200 years ago. There have been at least 17 volcanic eruptions in the past 4000 years. Most of the time dacite was extracted, a more viscous magma than the basalt and andesite that had previously emerged .

The local climate is subtropical and mild with annual precipitation of around 1500 millimeters and the occasional occurrence of cyclones . The densely forested island is home to at least 23 species of plants and five species of birds that are endemic (i.e. found nowhere else in the world). At least minor earthquakes occur here practically every day.

history

Archaeological finds document the use of the island from the 14th century by people who came from Polynesia . The finds also include obsidian from Mayor Island near New Zealand's North Island, which is seen as an indication of travel from New Zealand to islands further north. The Māori mythology According used in the settlement of New Zealand two canoes, the Kermadec Islands as a stopover. The Kurahaupō canoe at Raoul Island was damaged by a reef .

From a European point of view, Raoul Island was discovered on March 16, 1793 by the French admiral Joseph Bruny d'Entrecasteaux . He named the island after the quartermaster of one of his two ships. In March 1796, the captain of the whaler Britannia sighted the island and named it Sunday Island . This name was initially able to establish itself. In the decades that followed, whalers used the island to stock up on wood and water. Goats were released on the island to provide fresh meat. In 1854 the British Henry Mangles Denham mapped the island.

From the 1830s on, there were few families on the island who sold provisions to ships passing by. After a volcanic eruption in June 1870, the settlers fled into the interior of the island; in October 1870 they were evacuated. During the eruption, two new islands with a height of about 100 meters were temporarily created in Denham Bay. A phreatic explosion occurred in the Raoul Caldera, creating a new crater 600 meters in diameter. As early as 1814, after an eruption in Denham Bay, a new island about five kilometers in circumference had formed; which sank again before 1854.

In 1887 New Zealand annexed Raoul Island. In 1878 people had resettled on the island. Among other things, they grew fruit, especially oranges. The attempt at settlement finally failed in 1938 because Raoul Island did not have a safe harbor for exporting agricultural products. In the present, only small boats can moor in calm weather. In 1939, Raoul Island became the island's official name; in the same year a weather station was set up in the northwest of the island .

During the First World War , the settlers were evacuated to New Zealand. In May and June 1917, the German auxiliary cruiser SMS Wolf used the island as an anchorage for a thorough overhaul, which mainly affected the machinery. Near the island, two previously made prizes of the Wolf , the New Zealand freighter Wairuna and the American Bark Winslow , were sunk after taking over the usable cargo. Two prisoners managed to escape from the ship shortly before the auxiliary cruiser left the port, and at least one could have reached the island. A targeted search operation undertaken by the New Zealand Navy in May 1918 was unsuccessful.

In 1954 the British government asked permission to test a hydrogen bomb on Raoul Island . The Raoul Caldera was seen as a suitable area. The application was rejected by New Zealand on political grounds. In November 1964, another brief volcanic eruption occurred in the Raoul Caldera, in which several new craters were formed and ash and steam rose a good kilometer high.

Since 1988, the Department of Conservation (DOC), the New Zealand authority responsible for nature conservation, has managed the island, which has been a nature reserve since 1934. The DOC took over the weather station and from there carries out weather measurements, the observation of volcanic activity as well as various maintenance and monitoring work. In 2002 the cats and rats were exterminated on the island. In the years that followed, several species of birds, including the Kermadec petrel , returned to the island to breed. On March 17, 2006, a DOC employee was killed by a volcanic eruption in the Raoul Caldera.

In 2008, five DOC employees were permanently on the island. They were assisted by six volunteers who mostly cleaned up weeds during five to six month long missions. Otherwise the island is uninhabited. Visitors need a permit from the DOC before landing.

Secondary islands and rocks

Raoul Island with a view of the minor islands to the northeast

Around the main island Raoul Island are grouped a few smaller islands and rocks protruding from the sea, the largest of which are the Meyer Islands.

Web links

Commons : Raoul Island  - collection of images, videos and audio files

Individual evidence

  1. ↑ Tim J. Worthington, Murray R. Gregory, Vladislav Bondarenko: The Denham Caldera on Raoul Volcano: dacitic volcanism in the Tonga – Kermadec arc. In: Journal of Volcanology and Geothermal Research. 90, 1999, ISSN  0377-0273 , pp. 29-48, here p. 31 f.
  2. ^ Worthington et al.: The Denham Caldera. 1999, p. 46.
  3. ^ A b John H. Latter, Edwards F. Lloyd, Ian EM Smith, Simon Nathan: Kermadec Islands Geology. at the Institute of Geological and Nuclear Sciences (accessed January 16, 2013).
  4. ↑ a b Kermadec Islands - Features at the Department of Conservation (accessed January 16, 2013).
  5. ↑ Simon Nathan: Kermadec Islands - Human impact and Pou whenua on Raoul Island. In: Te Ara: The Encyclopedia of New Zealand . (Version of September 10, 2012).
  6. ↑ a b Simon Nathan: Kermadec Islands - Raoul Island. In: Te Ara: The Encyclopedia of New Zealand. (Version of September 10, 2012).
  7. ↑ a b c Eileen McSaveney, Carol Stewart, Graham Leonard: Historic volcanic activity - Raoul Iceland. In: Te Ara: The Encyclopedia of New Zealand. (Version dated April 2, 2012).
  8. ^ Worthington et al.: The Denham Caldera. 1999, p. 37.
  9. ↑ Peter honing, Richard Guilliatt: The Wolf. Free Press, New York 2010, ISBN 978-1-4165-7317-3 .
  10. ^ Raoul Island Resupply . In: Navy Today . tape  134 , July 2008 (English, navy.mil.nz ( Memento from May 21, 2010 in the Internet Archive ) [accessed May 5, 2018]).
  11. ↑ Kermadec Islands Nature Reserves & Marine Reserve . (PDF PDF110kB) Department of Conservation , June 2002, archived from the original on June 1, 2013 ; accessed on May 4, 2018 (English, original website no longer available).