McDonald Islands

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Unusual changes transformed McDonald Islands in the time period from 2000 to 2001. Volcanic eruptions and (possibly) rise of the land increased the area of main McDonald Island from 1.13 km² to 2.45 km², rising the height of tallest mountain from 186 to 230 m.

Late discovery

McDonald Islands are very remote and little known islands. They were first sighted exactly 157 years ago – in January 4, 1854 – from ship "Samarang" and were named after the captain William McDonald. Highest (then) hill on island was named after ship – Samarang Hill. This is comparatively late discovery of new lands outside polar regions.

Back then this was a group of three small islands – 186 m high McDonald Island itself, 55 m high Flat Island a little north from it and Meyer Rock – impressive cliff rising from the sea 1.9 km to the north-west from McDonald Island. By the way – Meyer Rock is barely visible on Google Earth.

Although island represented a summit of volcano, it seemed to be a relatively peaceful place with many thousands of macaroni penguins (Eudyptes chrysolophus) breeding on it (see image).

People have not lived here and up to this day the island has been visited few times. One of the main reasons for rare visits is nearly impossible landing due to permanently rough sea.

Sudden eruptions

Volcano of McDonald Island was dormant for 75,000 years but in 1992 it suddenly became active. Several eruptions have taken place since then with volcanic plumes observed in December 1996 and January 1997, when floating pumice reached also Heard Island.

Especially significant changes took place in 2000 – 2001. Satellite image from November 2000 shows no major changes to the island geography. Image from 2001 though shows completely different picture. Island has extended, mainly towards the north, joining with Flat Island. The highest point of island has shifted to the north.

Last known eruption took place in 2005.

Island is built of layered phonolitic tuff and cut by phonolitic dikes – thus the geology here is completely different from the geology of 45 km distant Heard Island. During the eruption volcano exuded highly viscous, slowly flowing lava.

Google Earth image shows muddy water around the island – active erosion process is ongoing and newly extended island again is washed out. Western side of the island is exposed to rough winds and constant giant waves – it represents giant, more than 200 m tall vertical cliff.

Return of life

During the eruptions there was destroyed almost all vegetation of island. Nevertheless satellite images show green patches of plants – they are quickly colonising the new land.

Most likely eruptions disturbed also macaroni penguins. But the pumice fields may represent a good breeding site for them and it is possible that also king penguins (Aptenodytes patagonicus) will choose to breed here – or may be they already are here.

References

  1. McDonald Island, image from the times when there were three separate islands, accessed 03.01.11.
  2. McDonald Island, rare image taken on the island in 1980, accessed 03.01.11.

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McDonald Islands -53.041183, 72.596772 McDonald Islands
Coordinates: 53.0412 S 72.5968 E
Categories: Volcanoes
Values: Geology, Visual
Rating: (2 / 5)
Address: Antarctic and Sub-antarctic region, Australia, Heard Island and McDonald Islands, McDonald Island
Alternate names: McDonald Islands
Height: 230 m?
Last eruption: 2005?

Landmarks of Heard Island and McDonald Islands

Possible eruption on Heard Island
Possible eruption on Heard Island / NOAA / public domain
Heard Island and McDonald Islands are some of the most remote islands in the world. Very few people have visited them but these islands represent truly remarkable sight.

Islands were included in UNESCO World Heritage List in 1997 and represent unique site where can be observed unusually fast geomorphological processes and unique, undisturbed ecosystem.

Volcanoes

Mount Cleveland, Aleut Islands
Mount Cleveland / NOAA Photo Library, / CC BY 2.0
Over the last 10,000 years in some 1,500 places around the Earth through the crust of the planet has been emitted lava, ash and gases from the mantle of Earth. Each of these places could be considered to be an active volcano.

Recommended books

Heard and McDonald Islands, World Heritage Site


The Territory of Heard Island and McDonald Islands (HIMI) which includes the islands and the surrounding ocean to 12 nautical miles from shore was inscribed on the World Heritage List in 1997 for its outstanding universal natural values. The human history of Heard Island and the surrounding waters is relatively short, with the first confirmed sighting of the Island in 1853, and the first landing in 1854.

Heard Island: Southern Ocean Sentinel

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