Glaciated valleys in Europe and western Asia

Günther Prasicek,Jan-Christoph Otto,David R Montgomery,Lothar Schrott

doi:10.1080/17445647.2014.921647

Günther Prasicek, Jan-Christoph Otto + Show 2 more

Open Access

https://doi.org/10.1080/17445647.2014.921647

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Abstract

In recent years, remote sensing, morphometric analysis, and other computational concepts and tools have invigorated the field of geomorphological mapping. Automated interpretation of digital terrain data based on impartial rules holds substantial promise for large dataset processing and objective landscape classification. However, the geomorphological realm presents tremendous complexity and challenges in the translation of qualitative descriptions into geomorphometric semantics. Here, the simple, conventional distinction of V-shaped fluvial and U-shaped glacial valleys was analyzed quantitatively using multi-scale curvature and a novel morphometric variable termed Difference of Minimum Curvature (DMC). We used this automated terrain analysis approach to produce a raster map at a scale of 1:6,000,000 showing the distribution of glaciated valleys across Europe and western Asia. The data set has a cell size of 3 arc seconds and consists of more than 40 billion grid cells. Glaciated U-shaped valleys commonly associated with erosion by warm-based glaciers are abundant in the alpine regions of mid Europe and western Asia but also occur at the margins of mountain ice sheets in Scandinavia. The high-level correspondence with field mapping and the fully transferable semantics validate this approach for automated analysis of yet unexplored terrain around the globe and qualify for potential applications on other planetary bodies like Mars.

Highlights

The extent and chronology of past glaciations in Europe have been studied by geoscientists since the nineteenth century. Agassiz (1840) recognized erratic boulders and glacial striations as indicators for a once-extensive European ice shield, Penck and Bruckner (1909) reconstructed ice ages from moraines and terraces to produce large-scale maps, and van Husen (1987) mapped the last glacial maximum (LGM) extent of the eastern European Alps
Probabilities switch for all samples at a Difference of Minimum Curvature (DMC) of approximately 21.15 and we applied this value to the entire study area to predict the existence of glaciated valleys
The glacial Norwegian fjords sample and the fluvial Greater Caucasus sample differ from the other areas. This can be explained by the related morphology: The Caucasus sample shows a large amount of sediment fill in fluvial valleys, and the Norwegian fjords sample, which is known to represent glaciated U-shaped terrain (e.g. Steer et al, 2012), does not show glacial valleys as distinctive as the other samples due to missing cell values on sea-covered valley floors

Summary

Introduction

The extent and chronology of past glaciations in Europe have been studied by geoscientists since the nineteenth century. Agassiz (1840) recognized erratic boulders and glacial striations as indicators for a once-extensive European ice shield, Penck and Bruckner (1909) reconstructed ice ages from moraines and terraces to produce large-scale maps, and van Husen (1987) mapped the last glacial maximum (LGM) extent of the eastern European Alps. The extent and chronology of past glaciations in Europe have been studied by geoscientists since the nineteenth century. Quaternary glaciations around the world, providing a collection of digital data sets of glacial extent from various sources. For the vast majority of the documentation of glacial extent, mapping was carried out in the field. Andrews, Davis, & Wright, 1976; Boulton & Clark, 1990), digital terrain models Clark, 1997; Paul, Kaab, Maisch, Kellenberger, & Haeberli, 2002) Over the last several decades has supporting information been extracted from satellite-based remote-sensing data (e.g. Andrews, Davis, & Wright, 1976; Boulton & Clark, 1990), digital terrain models (e.g. Berthier et al, 2007; Mohr, Reeh, & Madsen, 1998), or a combination of both (e.g. Clark, 1997; Paul, Kaab, Maisch, Kellenberger, & Haeberli, 2002)

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