The properties of streamlined glacial landforms and palaeo-flow indicators in the valleys of Viðidalur, Vatnsdalur and Sv ınadalur in northern Iceland were quantified using spatial analyses. Drumlins and mega-scale glacial lineations (MSGL) were visually identified using satellite imagery from Google Earth, the National Land Survey of Iceland (NLSI) Map Viewer and Landsat satellites, and using aerial photographs from the NLSI. A semi-automated technique was developed using ENVI to determine regions in northern Iceland likely to contain streamlined landforms. The outlines of the identified landforms were manually delineated in Google Earth, and all analyses were conducted in ArcGIS using a 20 m digital elevation model (DEM) of Iceland from the NLSI. Smaller features such as flutes, grooves and striations were measured in the field. At least 543 drumlins and 90 MSGL were identified in the three valleys. Average elongation ratios for Viðidalur, Vatnsdalur and Sv ınadalur are 4.3:1, 5.2:1 and 6.7:1, respectively. The average density of streamlined landforms is 2.34 landforms per 1 km 2 . Striations and orientation data of the drumlins and MSGL demonstrate ice flow to the northwest into H unafl oi. Parallel conformity is higher in the valley of Sv ınadalur (9°standard deviation) than in Viðidalur (12°) and Vatnsdalur (16°). Packing values are generally higher in the centre of each valley. The properties of streamlined landforms in the valleys of Viðidalur, Vatnsdalur and Sv ınadalur support the presence of palaeo-ice stream activity on northern Iceland. Palaeo-ice streams flowed from these regions into H unafl oi, supplying ice to the margin of the Iceland Ice Sheet during the Last Glacial Maximum. These palaeo-ice streams provide a mechanism for ice centres from the mainland of Iceland to reach the shelf-slope break.
This study is a quantitative analysis of cirques in three regions of Iceland: Tröllaskagi, the East Fjords and Vestfirðir. Using Google Earth and the National Land Survey of Iceland Map Viewer, we identified 347 new cirques on Tröllaskagi and the East Fjords region, and combined these data with 100 cirques previously identified on Vestfirðir. We used ArcGIS to measure length, width, aspect, latitude and distance to coastline of each cirque. Palaeo‐equilibrium‐line altitudes (palaeo‐ELAs) of palaeo‐cirque glaciers were calculated using the altitude‐ratio method, cirque‐floor method and minimum‐point method. The mean palaeo‐ELA values in Tröllaskagi, the East Fjords and Vestfirðir are 788, 643 and 408 m a.s.l, respectively. Interpolation maps of palaeo‐ELAs demonstrate a positive relationship between palaeo‐ELA and distance to coastline. A positive relationship between palaeo‐ELA and latitude is observed on Vestfirðir, a negative relationship is observed on Tröllaskagi and no statistically significant relationship is present on the East Fjords. The modal orientation of cirques on Tröllaskagi and Vestfirðir is northeast, while orientation of cirques in the East Fjords is north. Palaeo‐wind reconstructions for the LGM show that modal aspect is aligned with the prevailing north‐northeast wind directions, although aspect measurements demonstrate wide dispersion. Cirque length is similar on Tröllaskagi and the East Fjords, but cirques are approximately 200 m shorter in Vestfirðir. Cirque widths are similar in all three regions. Comparisons with a global data set show that cirques in Iceland are smaller and more circular than cirques in other regions of the world. Similar to glaciers in Norway and Kamchatka, our results demonstrate that access to a moisture source is a key parameter in determining palaeo‐ELAs in Iceland. Temperatures interpreted from palaeo‐ELA depressions suggest that these cirques may have been glaciated as recently as the Little Ice Age.
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