Balleny Islands

From Vero - Wikipedia
Jump to navigation Jump to search

Template:Short description Template:Use New Zealand English

Template:Use dmy dates Template:Infobox islands

The Balleny Islands from a sketch by John MacNab, a crew member of the ship Eliza Scott that visited the Balleny Islands in 1839. In a description of this sketch in his 1905 history of Antarctic exploration, H.R. Mill drew attention to "smoke rising from an active volcano on Buckle Island".<ref name="Mill_1905">Template:Cite book</ref> This sketch supports findings suggesting Buckle Island as the source of volcanic cryptotephra layers deposited in Marie Byrd Land in 1839.<ref>Template:Cite journal</ref>
The Balleny Islands (top) and Antarctic coast (bottom) from space, December 2007. Dark patches are ice-free sea surface.

The Balleny Islands (Template:Coord) are a series of uninhabited islands in the Southern Ocean extending from 66°15' to 67°35'S and 162°30' to 165°00'E. The group extends for about Template:Convert in a northwest–southeast direction. The islands are heavily glaciated and of volcanic origin. Glaciers project from their slopes into the sea. The islands were formed by the so-called Balleny hotspot.

The group includes three main islands: Young, Buckle and Sturge, which lie in a line from northwest to southeast, and several smaller islets and rocks:

  • northeast of Young Island: Seal Rocks, Pillar
  • southeast of Young Island: Row Island, Borradaile Island (with Swan Base shelter hut)
  • south of Buckle Island: Scott Cone, Chinstrap Islet, Sabrina Islet (with Sabrina Refuge shelter hut), and the Monolith

The islands are claimed by New Zealand as part of the Ross Dependency (see Territorial claims in Antarctica).

Islands and rocks from north to south

Island/Rock Area Highest peak
Template:Km2 Template:Mi2 m ft
Young Island and satellite islets
Seal Rocks Template:Convert Template:Convert
Pillar Template:Convert Template:Convert
Young Island Template:Convert Template:Convert Template:Br (Freeman Peak)
Row Island Template:Convert Template:Convert
Borradaile Island Template:Convert Template:Convert
Beale Pinnacle Template:Convert Template:Convert
Buckle Island and satellite islets
Buckle Island Template:Convert Template:Convert
Scott Cone Template:Convert Template:Convert
Eliza Cone Template:Convert Template:Convert
Chinstrap Islet Template:Convert
Sabrina Island Template:Convert Template:Convert
The Monolith Template:Convert Template:Convert
Sturge Island (no satellite islets)
Sturge Island Template:Convert 1,705<ref name="SCAR1">Brown Peak, Composite Gazetteer of Antarctica, Scientific Committee on Antarctic Research. US source.</ref> or Template:Br 1524<ref name="SCAR2">Brown Peak, Composite Gazetteer of Antarctica, Scientific Committee on Antarctic Research. NZ source.</ref> 5,594 or Template:Br 5,000 Template:Br (Brown Peak)

The islands' area totals Template:Convert and the highest point has been measured as Template:Convert<ref name="SCAR1"/> or approximately Template:Convert<ref name="SCAR2"/> (the unclimbed Brown Peak on Sturge Island).

The Antarctic Circle is close to Borradaile Island, in the eight-kilometre channel between Young and Buckle Islands. Buckle Island and the nearby Sabrina Island is home to several colonies of Adelie and chinstrap penguins.

Recorded human visits to the islands

The English sealing captains John Balleny and Thomas Freeman first sighted the group in 1839.<ref name=faure>Template:Cite book</ref> Balleny named the island group after himself and the individual islands after the London merchants whose financial backing had made the expedition possible. Freeman was the first person known to land on any of the islands on 9 February 1839, and this was the first recorded human landfall south of the Antarctic Circle.

Sealers sighted the islands in 1853 but did not land.<ref>R.K. Headland (ed.) Historical Antarctic sealing industry, Scott Polar Research Institute, University of Cambridge, 2018, p.169 Template:ISBN</ref>

In 1948, the islands were surveyed by the Australian National Antarctic Research Expeditions aboard Template:HMAS. A small landing party led by Stuart Campbell made landfall in a whaleboat on 29 February 1948, apparently the first people to set foot on the islands since their discovery in 1839.<ref>Template:Cite news</ref>

In February 2015 the islands were visited for three days by the New Zealand-Australia Antarctic Ecosystems Voyage under the auspices of the New Zealand National Institute of Water and Atmospheric Research aboard the vessel RV Tangaroa, with the objective of studying marine life ecosystems of the islands, especially with reference to the humpback whale.<ref>Template:Cite web</ref> This work followed up work done on a previous visit in 2010.

On 3 February 2017, personnel from the Swiss Polar Institute's Antarctic Circumnavigation Expedition visited the islands and carried out considerable photographic and video survey work which was intended to contribute to the first accurate mapping of the main islands.<ref>Template:Cite web</ref> Most of the work was done by helicopter, although at least one landfall was also made on the islands by this expedition, using Zodiac inflatable boats.

Geology

In the archipelago, the Buckle, Sturge and Young Islands are examples of stratovolcanoes.<ref>Template:Cite web</ref> Strong earthquakes very close to the islands are rare, but tremors of moderate strength do occur over the Pacific-Antarctic Ridge, Macquarie triple junction and Pacific Rim between the Balleny Islands and Macquarie Island.<ref>Template:Cite web</ref> Other earthquakes occur near the Southeast Indian Ridge and Balleny fracture zone, including a magnitude 8.1 earthquake in 1998 that struck just over Template:Convert west-northwest of the islands<ref>Template:Cite web</ref> which changed the pattern of seismicity in a wide area around the islands.<ref>Template:Cite web</ref>

It is possible that these islands are still volcanically active. The Brown Peak volcano may have had an eruption in 2001, based on satellite observation.<ref>Template:Cite journal</ref>

Weather

The islands experience strong weather with powerful winds and regular gales for much of the year. Cloud cover is present most of the time with an average of only 15 days of blue sky a year.<ref>Template:Cite book</ref>

Submerged features

Several underwater features lie close to the Balleny Islands:

See also

Template:Portal

References

Template:Reflist

Template:Commons category

Template:Authority control