East Antarctic Ice Sheet

The East Antarctic Ice Sheet (EAIS) is one of two large ice sheets in Antarctica, and the largest on the entire planet. The EAIS lies between 45° west and 168° east longitudinally.

The EAIS is considerably larger in area and mass than the West Antarctic Ice Sheet (WAIS). It is separated from the WAIS by the Transantarctic Mountains. The EAIS rests upon a large land mass, contrary to that of the WAIS, which rests mainly on bedrock below sea level.[1] The EAIS is also home to the thickest ice on the frozen white continent, at 15,700 ft (4,800 m). More well known, however, is that the EAIS is home to the geographic South Pole as well as of the Amundsen-Scott South Pole Station.

Ice mass changes

Current international focus on global warming issues has drawn attention to the melting of the polar ice caps. An early analysis of GRACE-based studies data indicated that the EAIS was losing mass at a rate of 57 billion tonnes per year[2] and that the total Antarctic ice sheet (including WAIS, and EAIS coastal areas) was losing mass at a rate of 152 cubic kilometers (c. 139 billion tonnes) per year.[3] More recent estimate published in November 2012 and based on the GRACE data as well as on an improved glacial isostatic adjustment model indicates that East Antarctica actually gained mass from 2002 to 2010 at a rate of 60 ± 13 Gt/y.[4]

It has been estimated that during the Pleistocene, the East Antarctic Ice Sheet thinned by at least 500 meters, and that thinning since the Last Glacial Maximum is less than 50 meters and probably started after ca 14 ka.[5]

Temperature changes

Cooling in East Antarctica during the decades of the 1980s and 1990s partially offset warming of the West Antarctic Ice Sheet which has warmed by more than 0.1°C/decade in the last 50 years. The continent-wide average surface temperature trend of Antarctica is positive and statistically significant at >0.05°C/decade since 1957.[6]

Territorial claims

Many countries hold a claim on portions of Antarctica. Within EAIS, the United Kingdom, France, Norway, Australia, Chile and Argentina all claim a portion (sometimes overlapping) as their own territory.

See also

References

  1. ↑ Ice Sheets in Antarctica British Antarctic Survey
  2. ↑ Chen, J. L.; Wilson, C. R.; Blankenship, D.; Tapley, B. D. (2009). "Accelerated Antarctic ice loss from satellite gravity measurements". Nature Geoscience 2 (12): 859. Bibcode:2009NatGe...2..859C. doi:10.1038/ngeo694.
  3. ↑ Velicogna, Isabella; Wahr, John; Scott, Jim (2006-03-02). "Antarctic ice sheet losing mass, says University of Colorado study". EurekAlert.org. University of Colorado at Boulder. Retrieved 22 October 2011.
  4. ↑ King, M. A.; Bingham, R. J.; Moore, P.; Whitehouse, P. L.; Bentley, M. J.; Milne, G. A. (2012). "Lower satellite-gravimetry estimates of Antarctic sea-level contribution". Nature 491 (7425): 586–589. Bibcode:2012Natur.491..586K. doi:10.1038/nature11621. PMID 23086145.
  5. ↑ Yusuke Suganuma, Hideki Miura, Albert Zondervan, Jun'ichi Okuno (August 2014). "East Antarctic deglaciation and the link to global cooling during the Quaternary: evidence from glacial geomorphology and 10Be surface exposure dating of the Sør Rondane Mountains, Dronning Maud Land". Quaternary Science Reviews 97: 102–120. Bibcode:2014QSRv...97..102S. doi:10.1016/j.quascirev.2014.05.007.
  6. ↑ Steig, E. J.; Schneider, D. P.; Rutherford, S. D.; Mann, M. E.; Comiso, J. C.; Shindell, D. T. (2009). "Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year". Nature 457 (7228): 459–462. Bibcode:2009Natur.457..459S. doi:10.1038/nature07669. PMID 19158794.

External links

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