GEOMORPHIC ANALYSIS OF STREAMLINED LANDFORMS IN NORTHERN ICELAND: EVIDENCE FOR PALEO-ICE STREAMS

Using a combination of fieldwork and spatial analyses, properties of streamlined landforms and paleo-flow indicators in the valleys of Viðidalur, Vatnsdalur, and Svínadalur in northern Iceland were quantified. Drumlins and megascale glacial lineations (MSGL) were visually identified using satellite imagery from Google Earth, the National Land Survey of Iceland- Map Viewer, and Landsat satellites, and using aerial photographs from the National Land Survey of Iceland. A semi-automated technique was developed using the program ENVI to determine regions in northern Iceland likely to contain streamlined landforms. The outlines of the identified landforms were manually delineated in Google Earth, exported as a KML file, and imported into ArcGIS. All analyses of the streamlined landforms were conducted in ArcGIS using a 20 m digital elevation model (DEM) of Iceland from the National Land Survey of Iceland. Smaller features such as flutes, grooves, and striations were measured in the field. Approximately 530 drumlins and 90 MSGL were identified in these valleys, with 99 % of the MSGL located in the Svínadalur region. Average elongation ratios for Viðidalur, Vatnsdalur, and Svínadalur are 4.3: 1, 4.8:1, and 6.8:1 respectively. The average density of streamlined landforms in the three valleys is similar ranging from 1.1 – 1.6 landforms per square kilometer. Striations and orientation data of the drumlins and MSGL demonstrate ice flow to the northwest and flowing into Húnaflói. Parallel conformity varies from 4.7 degrees in Viðidalur to 7.1 degrees in Vatnsdalur. Morphometric analyses of landforms in all three valleys are indicative of fast paleo-ice flow in northern Iceland. Paleo-ice streams flowed from these regions into Húnaflói, supplying ice to the LGM margin of the Iceland Ice Sheet.