GEOMORPHIC EVIDENCE FOR PALEO-ICE STREAM ACTIVITY IN NORTHERN ICELAND

The properties of streamlined landforms and paleo-flow indicators in the valleys of Viðidalur, Vatnsdalur, and Svínadalur in northern Iceland were quantified using a combination of fieldwork and spatial analyses. Drumlins and mega-scale glacial lineations (MSGL) were 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. The outlines of the identified landforms were drawn manually in Google Earth. All quantitative 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 Svínadalur are 4.3: 1, 5.2:1, and 6.7:1, respectively. The average density of streamlined landforms is 2.34 landforms per 1 km². Striations and orientation data of the drumlins and MSGL demonstrate ice flow to the northwest into Húnaflói. Parallel conformity is higher in the valley of Svínadalur (9° standard deviation) than in Viðidalur (12°) and Vatnsdalur (16°). Packing values are generally higher in the center of each valley. The properties of streamlined landforms in the valleys of Viðidalur, Vatnsdalur, and Svínadalur support the presence of paleo-ice stream activity on northern Iceland. During the Last Glacial Maximum, paleo-ice streams flowed from these regions into Húnaflói, supplying ice to the margin of the Iceland Ice Sheet at the shelf-slope break.