Proposal for geomorphological mapping of debris-covered and rock glaciers and its application to Tröllaskagi Peninsula (Northern Iceland)

Abstract

This work defends and applies a new proposal for mapping debris-covered glaciers and rock glaciers. This proposal combines highly accurate traditional methods, such as manual geomorphological photointerpretation, with novel digital techniques. The new methodological strategy applies rendering and lighting tools from Computer-Aided Design platforms and uses graphic design from Desktop Publishing Programs, to improve the geovisualization of geomorphological maps. This combination was applied to the debriscovered glacier and a set of rock glaciers located on the Tröllaskagi peninsula (northern Iceland). The result is a 1:4,500 scale geomorphological map of 16 km 2 , which for the first time maps the features that differentiate the debris-covered glacier from rock glaciers, as well as genetically different units within each formation and a long series of landforms characteristic of different processes. This map thus becomes a very useful tool in the evolutionary study of these formations in relation to the impact of climate change.

Constraints on the timing of debris-covered and rock glaciers: An exploratory case study in the Hólar area, northern Iceland

“…The collapsed fronts of the relict rock glaciers descend to an altitude of 850 m a.s.l., while the steep fronts of the active ones descend to 950 m a.s.l. (Tanarro et al, 2018(Tanarro et al, , 2019.…”

Héðinsdalsjökull, northern Iceland: geomorphology recording the recent complex evolution of a glacier

“…Although this sector is within the active debris-covered glacier, it has been interpreted as a developing of a rock glacier or 'proto-rock glacier', based on the abovementioned features (Figures 1-3 and 6). Incipient rock glaciers have also been detected in some nearby Tröllaskagi cirques, as in the Fremri-Grjótárdalur cirque (Tanarro et al, 2018(Tanarro et al, , 2019) (Figure 7).…”

“…To improve geovisualization of the geomorphology in the study area, a photorealistic 3D view of the geomorphological map was generated using the 3D tools of the CAD MicroStation Connect through the application of rendering techniques and solar lighting (Tanarro et al, 2018). This required the elaboration of a polygonal mesh from a point cloud, which was previously derived from 3D photo-reconstruction.…”

“…Other active debris-covered glaciers have been studied in nearby Tröllaskagi cirques, such as Hóladalsjökull (Tanarro et al, 2018(Tanarro et al, , 2019 and Hofsjökull (Campos et al, 2019). From a morphological point of view, Héðinsdalsjökull differs from them by the much higher density of collapse depressions and the limited preservation of moraine landforms.…”

“…Some debris-covered glaciers and rock glaciers have been studied according to their morphology and dynamics, and a number of authors have highlighted their low (or even null) dynamism, especially at rock glaciers, whose main dynamics is by surface subsidence (Andrés et al, 2016;Campos et al, 2019;Martin et al, 1991;Tanarro et al, 2019). Mapping of the Iceland proglacial cirque areas is a first approach to the complex geomorphological evolution that accompanies deglaciation (Evans et al, 2017;Tanarro et al, 2018).…”