Exploring the potential of Sentinel-1 InSAR for Pleistocene glacier reconstruction at Rumija, Montenegro

The record of Pleistocene glaciation in the Mediterranean remains incomplete, restricting our understanding of spatial variation in their extent and timing. Digital Elevation Models (DEM) could offer a basis for identifying glacial geomorphology and therefore address this issue. Currently, free DEM availability is limited to global datasets such as the 30m Shuttle Radar Topography Mission (SRTM), which are too low in spatial resolution for such applications. However, Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) has been investigated to offer a new higher spatial resolution DEM. This study examines the potential of Sentinel-1 InSAR derived DEM by investigating evidence of glaciation at Rumija, Montenegro. Interferometry of Sentinel-1 SAR imagery is used to generate a DEM covering Rumija. Root Mean Square Error (RMSE) indicates a high vertical inaccuracy of 67.5m compared to the SRTM. However, visual comparison shows the Sentinel-1 DEM better preserves topography than SRTM at elevations exceeding 400m. Geomorphological mapping is carried out using several DEM products and supported with satellite imagery. A range of karstic and glacial landforms are identified through the landscape, including a cirque on the north side of Rumija (1596m). Glacier reconstruction with Accumulation Area Ratio (AAR) is based on cirque morphology. A 0.15km² Pleistocene glacier is identified, with a DEM error adjusted Equilibrium Line Altitude (ELA) of 1332m. This correlates to the ELA range of the MIS-12 glaciation at Orjen, 75km north west. The Sentinel-1 InSAR derived DEM is demonstrated to be an effective free data source for the identification of glacial geomorphology.