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| Titel |
Investigating the dynamics of deglaciation in coastal areas of southeast Greenland |
| VerfasserIn |
Laurence M. Dyke, Anna L. C. Hughes, Camilla S. Andresen, Tavi Murray, John F. Hiemstra, Angel Rodes |
| 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 |
250135945
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| Publikation (Nr.) |
 EGU/EGU2016-16874.pdf |
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| Zusammenfassung |
| Southeast (SE) Greenland has experienced large glaciological changes over the last two
decades. Glacial retreat, acceleration, and thinning have resulted in substantial mass loss.
However, despite its significance, relatively little is known about the glacial history of SE
Greenland. Reconstructions of glacier behaviour provide valuable context for assessing the
magnitude of present-day changes, they can also be used to better-understand the
mechanisms that control glacier behaviour.
We present 11 new cosmogenic exposure ages from previously uninvestigated coastal
areas of SE Greenland. Paired erratic and bedrock samples from low-elevation locations were
analysed for 10Be content. Samples were collected from central areas of Køge Bugt and
Ikertivaq; consequently, these samples track the retreat of the major, marine terminating
outlet glaciers here. Samples from Gerner Ø and Tugtilik were collected from locations away
from major outlet glaciers; these samples track the deglaciation of ‘passive’ margins of the
Greenland Ice Sheet (GrIS). Comparing the timing of deglaciation in these areas with
different dynamic regimes permits investigation of the relative influence of ice dynamics on
deglaciation.
Results from 10Be analysis are complicated; understanding their significance requires
careful interpretation and consideration of the individual sample settings. The timing of
glacier retreat appears to have been largely dependent on the local physiographic setting and
glaciological regime. The deglaciation of Køge Bugt occurred broadly contemporaneously
with retreat in Sermilik Fjord, 100 km to the northeast. Fjord retreat in Køge Bugt
probably occurred in response to climatic amelioration at the start of the Holocene
(Hughes et al., 2012). The deglaciation of Ikertivaq occurred marginally later, but
likely also in response to early-Holocene climatic warming. The minor difference in
timing may be attributable to the specifc geometry of Ikertivaq. The deglaciation
of passive areas appears to have occurred later than in the major fjord systems;
this suggests that ice dynamic processes were a key driver of deglaciation in SE
Greenland.
References: Hughes, A. L. C.; Rainsley, E.; Murray, T.; Fogwill, C. J.; Schnabel, C., Xu,
S., 2012. Rapid response of Helheim Glacier, southeast Greenland, to early Holocene climate
warming. Geology 40, 427–430. |
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