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| Titel |
Ice velocity changes in the Ross and Ronne sectors observed using satellite radar data from 1997 and 2009 |
| VerfasserIn |
B. Scheuchl, J. Mouginot, E. Rignot |
| 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 ; 6, no. 5 ; Nr. 6, no. 5 (2012-09-21), S.1019-1030 |
| Datensatznummer |
250003784
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| Publikation (Nr.) |
 copernicus.org/tc-6-1019-2012.pdf |
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| Zusammenfassung |
| We report changes in ice velocity of a 6.5 million km2 region around
South Pole encompassing the Filchner-Ronne and Ross Ice Shelves and
a significant portion of the ice streams and glaciers that constitute their
catchment areas. Using the first full interferometric synthetic aperture
radar (InSAR) coverage of the region completed in 2009 and partial coverage
acquired in 1997, we processed the data to assemble a comprehensive map of
ice speed changes between those two years. On the Ross Ice Shelf, our results
confirm a continued deceleration of Mercer and Whillans Ice Streams with
a 12-yr velocity difference of −50 m yr−1 (−16.7%) and
−100 m yr−1 (−25.3%) at their grounding lines. The
deceleration spreads 450 km upstream of the grounding line and more than
500 km onto the shelf, beyond what was previously known. Ross and Filchner
Ice Shelves exhibit signs of pre-calving events, representing the largest
observed changes, with an increase in speed in excess of +100 m yr−1
in 12 yr. Other changes in the Ross Ice Shelf region are less significant.
The observed changes in glacier speed extend on the Ross Ice Shelf along the
ice streams' flow lines. Most tributaries of the Filchner-Ronne Ice Shelf
show a modest deceleration or no change between 1997 and 2009. Slessor
Glacier shows a small deceleration over a large sector. No change is detected
on the Bailey, Rutford, and Institute Ice Streams. On the Filchner Ice Shelf
itself, ice decelerated rather uniformly with a 12-yr difference in speed of
−50 m yr−1, or −5% of its ice front speed, which we
attribute to a 12 km advance in its ice front position. Our results show
that dynamic changes are present in the region. They highlight the need for
continued observation of the area with a primary focus on the Siple Coast.
The dynamic changes in Central Antarctica between 1997 and 2009 are generally
second-order effects in comparison to losses on glaciers in the
Bellingshausen and Amundsen Seas region and on the Antarctic Peninsula. We
therefore conclude that the dynamic changes shown here do not have a strong
impact on the mass budget of the Antarctic continent. |
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