Berkner Island

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Berkner Island
Berkner Island SAT.png
LIMA Satellite image of Berkner Island, Antarctica
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Berkner Island
Location in Antarctica
Geography
Location Antarctica
Coordinates 79°30′S47°30′W / 79.500°S 47.500°W / -79.500; -47.500
Area44,000 km2 (17,000 sq mi)
Area rank 31st
Length320 km (199 mi)
Width150 km (93 mi)
Highest elevation869 m (2851 ft)
Highest pointThyssenhöhe
Administration
Administered under the Antarctic Treaty System

Berkner Island (also known as the Berkner Ice Rise or as Hubley Island) is an Antarctic ice rise, where bedrock below sea level has caused the surrounding ice sheet to create a dome. If the ice cap were removed, the island would be underwater. [1] Berkner Island is completely ice-covered and is about 320 kilometres (200 mi) long and 150 kilometres (93 mi) wide, with an area of 44,000 km2 (17,000 sq mi). It is surrounded by the Filchner-Ronne Ice Shelf. The northernmost point of the Berkner is about 20 kilometres (12 mi) from the open sea. It lies in the overlapping portion of the Argentine and the British Antarctic territorial claims.

Contents

The island rises to 869 m (2,850 ft) (975 m or 3,200 ft, according to other sources) and separates the Ronne Ice Shelf from the Filchner Ice Shelf. It is characterized by two domes, Reinwarthhöhe in the north (698 m or 2,290 ft), and Thyssenhöhe in the south (869 m or 2,851 ft). It is indented by three bays on the eastern side, which are, from north to south, the McCarthy Inlet, the Roberts Inlet, and the Spilhaus Inlet. The southern tip is named the Mulvaney Promontory. Gould Bay is on the north coast. Berkner Island is about 150 km (93 mi) west of Luitpold Coast, Coats Land, the closest mainland of Eastern Antarctica. The Hemmen Ice Rise is 17 km (10.6 mi) off the northwest corner of Berkner Island.

History

Berkner Island was discovered by members of the United States-International Geophysical Year party from Ellsworth Station during the 1957–1958 season. It was named by the United States Advisory Committee on Antarctic Names after American physicist Lloyd Berkner, engineer with the Byrd Antarctic Expedition (1928–1930). [2]

Since 1990, Berkner Island has been a jumping-off point for a number of long-distance polar expeditions. Ben Saunders has planned an unsupported journey from the island to the South Pole and back, [3] and it was the start point of Henry Worsley's attempt to cross the Antarctic in 2015–16. [4]

In the 1994–1995 field season, the British Antarctic Survey (BAS), Alfred Wegener Institute and the Forschungsstelle für Physikalische Glaziologie of the University of Münster cooperated in a project drilling ice cores on the North (Reinwarthhöhe) and South (Thyssenhöhe) Domes of the island. [5] Between 2002 and 2005 a 948 meters (3,110 feet) core was drilled through to the bed at Thyssenhöhe by a team from BAS and the Laboratoire de Glaciologie et Géophysique de l’Environnement, Grenoble, [6] and radar work in 2005 and 2010-11 confirmed the existence of the Raymond Effect. [7] [8]

Important Bird Area

A 500 ha site on fast ice 5 kilometers (3.1 miles) north of the area where the Ronne Ice Shelf joins the north-western coast of Berkner Island, about 90 kilometers (56 miles) to the northwest of Gould Bay, has been identified as an Important Bird Area by BirdLife International because it supports an emperor penguin colony. The size of the colony was estimated as about 8,000 individual birds, based on 2009 satellite imagery. [9]

See also

Related Research Articles

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<span class="mw-page-title-main">Ice shelf</span> Large floating platform of ice caused by glacier flowing onto ocean surface

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<span class="mw-page-title-main">Filchner–Ronne Ice Shelf</span> Ice shelf in Antarctica

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<span class="mw-page-title-main">Roosevelt Island, Antarctica</span>

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<span class="mw-page-title-main">West Antarctica</span> Part of Antarctica that lies within the Western Hemisphere

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<span class="mw-page-title-main">Amery Ice Shelf</span> Ice shelf in Antarctica

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Hemmen Ice Rise is an ice rise 11 miles (18 km) long and 2 to 4 kilometres wide, with an estimated area of 55 square kilometres (21 sq mi), located 17 kilometres (11 mi) off the northwest corner of Berkner Island in the Ronne Ice Shelf, Antarctica. The feature appears for the first time on a chart prepared at Ellsworth Station in 1957 by Captain Finn Ronne, U.S. Navy Reserve. The ice rise was subsequently noted in U.S. Earth Resources Technology Satellite imagery. It was named by the UK Antarctic Place-Names Committee for George E. Hemmen, Executive Secretary of the Scientific Committee on Antarctic Research in 1972; he served with the Falkland Islands Dependencies Survey as a meteorological observer at Admiralty Bay, 1952–53, and as Base Leader at Deception Island, 1953–54, and with the Royal Society Antarctic Expedition, 1956.

<span class="mw-page-title-main">Second German Antarctic Expedition</span> Antarctic research expedition

The Second German Antarctic Expedition of 1911–1913 was led by Wilhelm Filchner in the exploration ship Deutschland. Its principal objective was to determine whether the Antarctic continent comprised a single landmass rather than separated elements, and in particular whether the Weddell Sea and Ross Sea were connected by a strait. In addition, an extensive programme of scientific research was undertaken. The expedition failed to establish a land base, and the ship became beset in the Weddell Sea ice, drifting north for eight months before reaching open water. The expedition was marred by considerable disagreement and animosity among its participants, and broke up in disarray.

<span class="mw-page-title-main">Edith Ronne Land</span> Unofficial name of a region of Antarctica

Edith Ronne Land was the unofficial name of that portion of Antarctica which is bordered by Palmer Land and Ellsworth Land to the West, Coats Land to the East, and the Filchner-Ronne Ice Shelf to the North. In December 2012, this region was officially named Queen Elizabeth Land by the British Government, which considers it part of the British Antarctic Territory.

<span class="mw-page-title-main">Rutford Ice Stream</span> Antarctic ice stream

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<span class="mw-page-title-main">Ellsworth Station</span> Antarctic base

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<span class="mw-page-title-main">Gould Bay</span> Camp

Gould Bay is a bay located at the junction of the Filchner Ice Shelf with the northeast corner of Berkner Island, in the southern Weddell Sea. It was discovered by the Ronne Antarctic Research Expedition, 1947–48, under the leadership of Commander Finn Ronne, U.S. Navy Reserve, who named this bay for Laurence M. Gould, geologist, geographer, and second in command of the Byrd Antarctic Expedition, 1928–30.

Raymond Effect is a flow effect in ice sheets, occurring at flow divides, which gives rise to disturbances in the stratigraphy, showing unusual arches or anticlines called Raymond Arches. The stratigraphy is detected by radio-echo sounding. The Raymond effect arises from the unusual flow properties of ice, as its viscosity decreases with stress. It is of importance because it provides field evidence for the flow properties of ice. In addition, it permits dating of changes in ice flow and the establishment of changes in ice thickness. The effect was first predicted by Charles F. Raymond. Raymond Arches and the Raymond Effect have been observed at numerous other ice divides e.g. Siple Dome, Fletcher Ice Rise, Berkner Island, Roosevelt Island, Korff Ice Rise.

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<span class="mw-page-title-main">Iceberg A-38</span> Large iceberg that split from the Filchner-Ronne Ice Shelf in Antarctica in 1998

A-38 was a large iceberg that split from the Filchner-Ronne Ice Shelf in Antarctica in October 1998. Soon after formation it split into two pieces, A-38A and A-38B, which drifted westwards on the Weddell Gyre. The icebergs moved north along the Antarctic Peninsula and reached its tip in February 2003. A-38A and A-38B increased speed in open sea and grounded in shallower waters to the east of South Georgia Island in December 2003. A-38A broke up into three pieces in March 2004 and drifted north where it decayed. A-38B split into two in April, with the eastern portion, now known as A-38G, drifting north and west to decay. The remainder of A-38B remained grounded, interfering with the foraging routes of seals and penguins in South Georgia, resulting in the deaths of their young. On 20 August A38-B broke into two, with the new portion drifting north and breaking up. The remainder of A-38B continued to break up through September 2004 and had completely decayed by 2005.

Filchner Station was a German research station in the Antarctic. Administered by the Alfred Wegener Institute for Polar and Marine Research, it was established in February 1982 on the Filchner–Ronne Ice Shelf. The first station in Antarctica to be mounted on jacks, the structure was raised each year to allow for the increase in height of the shelf by snowfall. It was also relocated around 1 kilometre (0.62 mi) southwards each year to account for drift of the ice shelf. In October 1998, Filchner Station was stranded on iceberg A-38 when it broke away from the ice shelf. Research operations were cancelled and an emergency salvage operation was carried out that removed the majority of the station by February 1999.

References

  1. "Flichner Ice Shelf". Archived from the original on 2011-10-15. Retrieved 2012-05-11.
  2. "SCAR Composite Gazetteer".
  3. "Ben Saunders – "Climate Change: Government policies and the impact on the ground" « Areté Club". Archived from the original on 2012-07-20. Retrieved 2012-01-02.
  4. Biography, ShackletonSolo.org Archived 2016-02-01 at the Wayback Machine . Retrieved 26 January 2016
  5. NASA.gov [ dead link ]|PALEOCLIMATE|LAND+RECORDS|BOREHOLES&OrigMetadataNode=GCMD&EntryId=89738616867620&MetadataView=Full&MetadataType=0&lbnode=mdlb3
  6. Mulvaney, R.; Alemany, O.; Possenti, P. (2007). "The Berkner Island (Antarctica) ice-core drilling project" (PDF). Annals of Glaciology . 47 (1): 115. Bibcode:2007AnGla..47..115M. doi:10.3189/172756407786857758. S2CID   55854112 . Retrieved 14 December 2020.
  7. Hindmarsh, R.C.A.; King, E.C.; Mulvaney, R.; et al. (2011). "Flow at ice-divide triple junctions: 2. Three-dimensional views of isochrone architecture from ice-penetrating radar surveys". Journal of Geophysical Research . 116 (F02024). doi:10.1029/2010JF001785. hdl: 20.500.11820/68fe4f33-75c6-4e8f-b511-2201147fde24 . S2CID   55008674 . Retrieved 19 August 2020.
  8. Kingslake, J.; Hindmarsh, R.C.A; Aðalgeirsdóttir, G.; et al. (2014). "Full-depth englacial vertical ice-sheet velocities measured using phase-sensitive radar". Journal of Geophysical Research . 119 (12): 2604–2618. Bibcode:2014JGRF..119.2604K. doi: 10.1002/2014JF003275 . S2CID   129824379.
  9. "Berkner Island northwest (Gould Bay)". BirdLife Data Zone. BirdLife International. 2015. Retrieved 25 October 2020.