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| Titel |
Gradual slowdown and thickening of Fimbulisen ice shelf, East Antarctica, over the past decade |
| VerfasserIn |
Jelte van Oostveen, Geir Moholdt, Andreas Kääb, Kenichi Matsuoka |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250150978
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| Publikation (Nr.) |
 EGU/EGU2017-15507.pdf |
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| Zusammenfassung |
| Fimbulisen is a fast-flowing (up to 780±10 ma−1) ice shelf in the Dronning Maud
Land region of East Antarctica. Fed by one of the few major outlet glaciers along
that coast, Jutulstraumen, the ice shelf has the potential to affect the stability of a
considerable part of the inland ice sheet. Here we present evidence of a slowdown and
thickening of Fimbulisen over the last decade. We derive ice shelf velocities using
synthetic aperture radar (SAR) data from Envisat in 2008 and Radarsat-2 in 2015. We
find that the speeds of Fimbulisen have decreased by 10±2 ma−1 over the last 7
years, which is confirmed with repeated GPS stake readings from 2010-2011. The
slow-down of Fimbulisen coincides with a gradual ice shelf thickening that we infer
from ICESat (2003-2009) and CryoSat-2 (2010-2016) altimetry. Available surface
mass balance data from Fimbulisen show no clear trends over the past decades,
suggesting that ice dynamics is the main explanation for the observed thickening.
Considering that Fimbulisen is in a long-term phase of advance after its main tongue
calved off in 1967, it is plausible that the slowdown is cyclic and related to the
longitudinal expansion of the ice shelf. In support of this theory we have found
several uncharted ice rumples and stationary icebergs near the eastern front of the
ice shelf, indicating the presence of shallow bathymetry that might affect the ice
shelf dynamics considerably in the event of ice shelf grounding or ungrounding. |
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