You Are In The Old Site Archive - Click Here To See The Main Site With Current Stories

Antarctic Sea Ice Thicker Than Thought

25.11.2014
25.11.2014 11:28 Age: 3 yrs

Estimates of the thickness and volume of Antarctic sea ice will need to be revised upwards in the wake of new research

Click to enlarge. The WHOI SeaBED AUV ‘Jaguar’ heads out on its final mission during SIPEX-II from the stern of the Australian icebreaker RV Aurora Australis. Courtesy: Klaus Meiners, AAD (image) and Peter Kimball, WHOI (post-processing)

Click to enlarge. WHOI SeaBED AUV ‘Jaguar’ being hoisted back to the ship after its mission. Courtesy: Guy Williams, ACECRC’

Click to enlarge. The WHOI SeaBED AUV ‘Jaguar’ ready for deployment through a very thin layer of Antarctic sea ice. Coutesy: Peter Kimball, WHOI

Thickest ice measured at 16m

Here is the text of a news release issued by the British Antarctic Survey regarding this research:

Press Release - Underwater robot sheds new light on Antarctic sea ice

Issue date: 24 Nov 2014
Number: 13/2014
End of news release

See also

Our feature exploring some of the reasons why Antarctic sea ice may be growing here.

Abstract

Satellites have documented trends in Antarctic sea-ice extent and its variability for decades, but estimating sea-ice thickness in the Antarctic from remote sensing data remains challenging. In situ observations needed for validation of remote sensing data and sea-ice models are limited; most have been restricted to a few point measurements on selected ice floes, or to visual shipboard estimates. Here we present three-dimensional (3D) floe-scale maps of sea-ice draft for ten floes, compiled from two springtime expeditions by an autonomous underwater vehicle to the near-coastal regions of the Weddell, Bellingshausen, and Wilkes Land sectors of Antarctica. Mean drafts range from 1.4 to 5.5 m, with maxima up to 16 m. We also find that, on average, 76% of the ice volume is deformed ice. Our surveys indicate that the floes are much thicker and more deformed than reported by most drilling and ship-based measurements of Antarctic sea ice. We suggest that thick ice in the near-coastal and interior pack may be under-represented in existing in situ assessments of Antarctic sea ice and hence, on average, Antarctic sea ice may be thicker than previously thought.

Citation

Thick and deformed Antarctic sea ice mapped with autonomous underwater vehicles by G. Williams, T. Maksym, J. Wilkinson, C. Kunz, C. Murphy, P. Kimball, H. Singh is published in Nature Geoscience on 24 November 2014, doi:10.1038/ngeo2299

Read the abstract and get the paper here.

Source

News release from the British Antarctic Survey here

Nature news release.