Abstract
The study of glacial landforms is important for understanding past subglacial processes and dynamics. The Nordenskiöldbreen forefield hosts numerous streamlined landforms resulting from a late Holocene glacier advance. Here, we present a geomorphological map constructed from remotely sensed imagery of both the marine and terrestrial environments. Sixteen drumlin bedforms have been identified in the mapped forefield–ten terrestrial and six submarine. A sedimentological investigation of drumlins in the Nordenskiöldbreen forefield shows that they are composed of pre-existing sediments draped by a thin layer of till which formed during the most recent advance of the glacier. Analysis of recent (2008–2012), high-resolution aerial imagery of all the glacier forelands in Svalbard suggests drumlin features are widespread. Here, we have identified 49 previously undocumented terrestrial glacier forefields, where subglacially streamlined landforms occur within the margins of the late Holocene glacier extent. Additionally, the location of 53 previously published submarine sites with streamlined landscape have been mapped. Thirty of these are sites with streamlines of late Holocene origin and 18 with Last Glacial Maximum (LGM) origin. Based on our detailed case study at the Nordenskiöldbreen forefield, and remote sensing survey, we suggest that drumlins in Svalbard form predominantly in forefields of glaciers with low-elevation termini, in areas with abundant fine-grained sediments, and where the glaciers are able to advance into an area of unconstrained topography.
| Original language | English |
|---|---|
| Pages (from-to) | 170-188 |
| Number of pages | 19 |
| Journal | GFF |
| Volume | 140 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 3 Apr 2018 |
Bibliographical note
Funding Information:We acknowledge students of UNIS course AG-210 (2013–2016) for help with excavating the sections. Dr Rickard Petterson, Uppsala University, for GPR data from Nordenskiöldbreen. The fieldwork was funded by Arctic Field Grant (2015) [grant number 246066] and UNIS. Anne Hormes, Skafti Brynjólfsson and Sverrir Jónsson are thanked for discussions during field work. Berit Jakobsen and Cathrine L. Fjeldstad are acknowledged for their help in locating old literature and maps from the Nordenskiöldbreen area. The authors acknowledges Nina Aradóttir for constructive discussions, Lena Rubensdotter for helpful feedback on the map and in the field, Anatoly Sinitsyn for help with Russian–English translation, as well as Alexander Hovland and Erland Marø for field assistance. Spitsbergen Retraced is acknowledged for the sharing of the photo mosaic of the original and reproduced overview photo of Nordenskiöldbreen (Fig. 15). Depth data are reproduced according to permission no. 13/G706 by the Norwegian Hydrographic Service. The authors acknowledge Carrie Jennings and an anonymous reviewer for their constructive reviews as well as Mark Johnson for editorial support.
Publisher Copyright:
© 2018, © 2018 Geologiska F�F6;reningen.
Other keywords
- Drumlin
- geomorphological map
- marine
- sedimentology
- streamlined landforms
- subglacial
- terrestrial