Submarine landforms and past ice flow in the Krossfjorden system, northwest Svalbard
Very high-resolution swath-bathymetric data, acquired by the Norwegian Hydrographic Service, have been analysed to investigate submarine landforms and their implications for the dynamics and extent of past ice flow in the whole of the Krossfjorden system, northwest Svalbard. The results from this st...
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Format: | Thesis |
Language: | English |
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Apollo - University of Cambridge Repository
2013
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Online Access: | https://dx.doi.org/10.17863/cam.12840 https://www.repository.cam.ac.uk/handle/1810/266769 |
Summary: | Very high-resolution swath-bathymetric data, acquired by the Norwegian Hydrographic Service, have been analysed to investigate submarine landforms and their implications for the dynamics and extent of past ice flow in the whole of the Krossfjorden system, northwest Svalbard. The results from this study confirm that ice extended out of the Krossfjorden system (to the shelf edge west of Svalbard) during the Late Weichselian glacial maximum. They also improve the understanding of the relative chronology of retreat through Krossfjorden, which represents the outer part of the fjord system under study. Two transverse ridges were the only ice-marginal features present within Krossfjorden proper, indicating a relatively rapid ice retreat from the continental shelf to the shallower inner fjords of the Krossfjorden system. This retreat was part of the Late Weichselian deglaciation of the northwestern part of the Svalbard-Barents Sea ice sheet. The bathymetric data from the innermost fjords and bays represent the advance and subsequent retreat of ice during the period known as the Little Ice Age, when ice on Svalbard reached a recent maximum about 100 years ago. These advances of the five tidewater glaciers in the Krossfjorden system varied from 2.3 to 5 km, with retreat rates of about 30 to 40 m a-1 from 1910 to 1966 and 10 to 45 m a-1 from 1966 to the present. This variation in retreat rate is attributed to local differences in glacier drainage-basin size, fjord depth and the presence of bedrock outcrops that provided pinning-points during retreat. The very recent deposition of these submarine landforms and the detail in the swath-bathymetric data (including small transverse ridges that in some cases represent annual glacier-terminus positions) have made it possible to produce descriptions and interpretations of the landforms, and to infer the dynamics and retreat rate of ice, at a higher resolution than elsewhere in the Svalbard archipelago. |
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