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| Titel |
A new bed elevation dataset for Greenland |
| VerfasserIn |
J. L. Bamber, J. A. Griggs, R. T. W. L. Hurkmans, J. A. Dowdeswell, S. P. Gogineni, I. Howat, J. Mouginot, J. Paden, S. Palmer, E. Rignot, D. Steinhage |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 7, no. 2 ; Nr. 7, no. 2 (2013-03-22), S.499-510 |
| Datensatznummer |
250017946
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| Publikation (Nr.) |
 copernicus.org/tc-7-499-2013.pdf |
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| Zusammenfassung |
| We present a new bed elevation dataset for Greenland derived from a
combination of multiple airborne ice thickness surveys undertaken between
the 1970s and 2012. Around 420 000 line kilometres of airborne data were
used, with roughly 70% of this having been collected since the year 2000,
when the last comprehensive compilation was undertaken. The airborne data
were combined with satellite-derived elevations for non-glaciated terrain to
produce a consistent bed digital elevation model (DEM) over the entire
island including across the glaciated–ice free boundary. The DEM was
extended to the continental margin with the aid of bathymetric data,
primarily from a compilation for the Arctic. Ice thickness was determined
where an ice shelf exists from a combination of surface elevation and radar
soundings. The across-track spacing between flight lines warranted
interpolation at 1 km postings for significant sectors of the ice sheet.
Grids of ice surface elevation, error estimates for the DEM, ice thickness
and data sampling density were also produced alongside a mask of
land/ocean/grounded ice/floating ice. Errors in bed elevation range from a
minimum of ±10 m to about ±300 m, as a function of distance
from an observation and local topographic variability. A comparison with the
compilation published in 2001 highlights the improvement in resolution
afforded by the new datasets, particularly along the ice sheet margin,
where ice velocity is highest and changes in ice dynamics most marked. We
estimate that the volume of ice included in our land-ice mask would raise
mean sea level by 7.36 m, excluding any solid earth effects that would
take place during ice sheet decay. |
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