Iceberg B-15

Iceberg B-15 was the world's largest recorded iceberg. With an area of over 11,000 km², it was larger than the island of Jamaica.

Background

Calved from the Ross Ice Shelf in March 2000, B-15 broke up into several pieces in 2000, 2002 and 2003, the largest of which, B-15A, was the world's largest free floating object at 27 x 122 km (17 x 76 mi) with an area of 3,100 km² (1,200 mi², approximately the size of Luxembourg). In November 2003, after the separation from B-15J iceberg, B-15A drifted away from Ross Island on the open waters of the Ross Sea.

In December 2003 a small knife-shaped iceberg, (about 300 km²), detached itself from the main body of B-15A and started drifting northward. In 2005 prevailing currents took B-15A slowly past the Drygalski ice tongue; the collision broke off the tip of Drygalski in mid-April.Then the iceberg sailed on along the coast leaving McMurdo Sound until it ran aground off Cape Adare in Victoria Land and broke into several smaller pieces on 27–28 October 2005. The largest piece is still named B-15A (its surface is now approx. 1,700 km²), while three additional pieces were named B-15P, B-15M and B-15N. It has since moved farther up north and broken up into more pieces. These were spotted by air force fisheries patrol on 3 November 2006. On 21 November several large pieces were seen just 60 km off the coast of Timaru, New Zealand. The largest measuring about 1.8 km (~1 mi) rising 37 m (120 ft) from the surface of the ocean.

Effect on Antarctic ecology

On 10 April 2005 B-15A impacted the Drygalski ice tongue, a projection of the fast-moving David Glacier that flows through Antarctica's mountainous Victoria Land coastal region, breaking off an 8-km² (3-mi²) section of the ice tongue. This collision with the Drygalski tongue forced a redrawing of Antarctic maps.

B-15A prevented ocean currents and winds from assisting in the 2004–2005 summer break-up of the sea ice in McMurdo Sound, and was an obstacle to the annual resupply ships to three research stations. The floe was expected to cause a catastrophic decline in the population of Adelie Penguins, as it added considerable distances which parent penguins must travel back from the sea to their chicks. Weddell seals and Skuas are also inhabitants of McMurdo Sound and their populations may have been affected as well.

In October 2006, it was reported that a storm in Alaska the previous year caused an ocean swell that broke B15A into many pieces. The waves travelled 13,500 km (8,300 mi) from Alaska to Antarctica over a six-day period. Scientists are studying this event as an example of how weather in one area can have effects in other parts of the world, and with concern over the effects on global warming. [cite web | author=Richard Harris | title=Alaskan Storm Plays Role of Butterfly for Antarctica | url=http://www.npr.org/templates/story/story.php?storyId=6204027 | publisher=National Public Radio, All Things Considered | date=5 October 2006 | accessdate=2008-01-12]

ee also

*Iceberg B-9
*Iceberg C-19
*McMurdo Sound

References

External links

* [http://earth.esa.int/ew/special_events/iceberg-b15_antartic/sp_iceberg-b15.htm ESA satellite monitoring] , updated frequently
* [http://glacierbliss.com/antarctica.html Pictures from 3 research trips to the icebergs]
* [http://uwamrc.ssec.wisc.edu/iceberg.html Satellite pictures of the iceberg's fragments from the Antarctic Meteorological Research Center]
* [http://envisat.esa.int/live/brockmann_archive/2006/MER_RR__1PNPDE20060302_213432_000025672045_00344_20939_3962.htm Situation around Balleby Islands; Icebergs B-15A, B-15N, C-19A] , ESA MERIS Level 1 Selected Image, 2 March 2006.
* [http://www.esa.int/esaCP/SEMCYK638FE_index_0.html Envisat shows behemoth B-15A iceberg breaking up] , ESA News, 7 November 2005.
* [http://news.bbc.co.uk/1/hi/sci/tech/4460335.stm Pile-up as berg hits Antarctica] , BBC News Online, 19 April 2005.
* [http://www.nasa.gov/vision/earth/lookingatearth/ice_berg_ram.html Get Ready for the Largest Demolition Derby on the Planet] , NASA, 6 January 2005.
* [http://www.guardian.co.uk/antarctic/story/0,13993,1374005,00.html The Iceberg Cometh] , "The Guardian", 15 December 2004.
* [http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=16759 NASA Earth Observatory images] , November - December 2004