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| Titel |
UAV photogrammetry and structure from motion to assess calving dynamics at Store Glacier, a large outlet draining the Greenland ice sheet |
| VerfasserIn |
J. C. Ryan, A. L. Hubbard, J. E. Box, J. Todd, P. Christoffersen, J. R. Carr, T. O. Holt, N. Snooke |
| 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 ; 9, no. 1 ; Nr. 9, no. 1 (2015-01-06), S.1-11 |
| Datensatznummer |
250116731
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| Publikation (Nr.) |
 copernicus.org/tc-9-1-2015.pdf |
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| Zusammenfassung |
| This study presents the application of a cost-effective, unmanned aerial
vehicle (UAV) to investigate calving dynamics at a major marine-terminating
outlet glacier draining the western sector of the Greenland ice sheet. The
UAV was flown over Store Glacier on three sorties during summer 2013 and
acquired over 2000 overlapping, geotagged images of the calving front at an
~40 cm ground sampling distance. Stereo-photogrammetry
applied to these images enabled the extraction of high-resolution digital elevation models (DEMs) with vertical accuracies of ± 1.9 m which were used
to quantify glaciological processes from early July to late August 2013. The
central zone of the calving front advanced by ~500 m, whilst
the lateral margins remained stable. The orientation of crevasses and the
surface velocity field derived from feature tracking indicates that lateral
drag is the primary resistive force and that ice flow varies across the
calving front from 2.5 m d−1 at the margins to in excess of
16 m d−1 at the centreline. Ice flux through the calving front is 3.8 × 107 m3 d−1,
equivalent to 13.9 Gt a−1 and comparable to
flux-gate estimates of Store Glacier's annual discharge. Water-filled
crevasses were present throughout the observation period but covered a
limited area of between 0.025 and 0.24% of the terminus and did not appear
to exert any significant control over fracture or calving. We conclude that
the use of repeat UAV surveys coupled with the processing techniques
outlined in this paper have great potential for elucidating the complex
frontal dynamics that characterise large calving outlet glaciers. |
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