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Titel |
Ice core evidence for a recent increase in snow accumulation in coastal Dronning Maud Land, Antarctica |
VerfasserIn |
Morgane Philippe, Jean-louis Tison, Karen Fjøsne, Bryn Hubbard, Helle Astrid Kjær, Jan Lenaerts, Simon Geoffrey Sheldon, Kevin De Bondt, Philippe Claeys, Frank Pattyn |
Konferenz |
EGU General Assembly 2016
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Medientyp |
Artikel
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Sprache |
en
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 18 (2016) |
Datensatznummer |
250136388
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Publikation (Nr.) |
EGU/EGU2016-17418.pdf |
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Zusammenfassung |
Ice cores provide temporal records of snow accumulation, a crucial component of Antarctic
mass balance. Coastal areas are particularly under-represented in such records, despite their
relatively high and sensitive accumulation rates. Here we present records from a 120 m ice
core drilled on Derwael Ice Rise, coastal Dronning Maud Land (DML), East Antarctica in
2012. We date the ice core bottom back to 1745 ± 2 AD. δ18O and δD stratigraphy
is supplemented by discontinuous major ion profiles, and verified independently
by electrical conductivity measurements (ECM) to detect volcanic horizons. The
resulting annual layer history is combined with the core density profile to calculate
accumulation history, corrected for the influence of ice deformation. The mean long-term
accumulation is 0.425 ± 0.035 m water equivalent (w.e.) a−1 (average corrected value).
Reconstructed annual accumulation rates show an increase from 1955 onward to a mean
value of 0.61 ± 0.02 m w.e. a−1 between 1955 and 2012. This trend is compared to
other reported accumulation data in Antarctica, generally showing a high spatial
variability. Applying the Community Earth System Model demonstrated that sea ice and
atmosphere patterns largely explain the accumulation variability. This is the first
and longest record from a coastal ice core in East Antarctica showing a steady
increase during the 20th and 21st centuries, thereby confirming modelling predictions. |
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