Long-term records of glacier surface velocities in the Ötztal Alps (Austria)

Martin Stocker-Waldhuber,Michael Kuhn,Andrea Fischer,Kay Helfricht

doi:10.5194/essd-11-705-2019

Abstract

Abstract. Climatic forcing affects glacier mass balance, which causes changes in ice flow dynamics and glacier length changes on different timescales. Mass balance and length changes are operationally used for glacier monitoring, whereas only a few time series of glacier dynamics have been recorded. Here we present a unique dataset of yearly averaged ice flow velocity measurements at stakes and stone lines covering more than 100 years on Hintereisferner and more than 50 years on Kesselwandferner. Moreover, the dataset contains sub-seasonal variations in ice flow from Gepatschferner and Taschachferner covering almost 10 years. The ice flow velocities on Hintereisferner and (especially) on Kesselwandferner show great variation between advancing and retreating periods, with magnitudes increasing from the stakes at higher elevations to the lower-elevated stakes, making ice flow records at ablation stakes a very sensitive indicator of glacier state. Since the end of the latest glacier advances from the 1970s to the 1980s, the ice flow velocities have decreased continuously, a strong indicator of the negative mass balances of the glaciers in recent decades. The velocity datasets of the four glaciers are available at https://doi.org/10.1594/PANGAEA.896741.

Highlights

The fluctuation of glaciers has become an icon of climate change, after Agassiz (1847) hypothesized the theory of ice ages, which was confirmed by Penck and Brückner (1909) and further substantiated with isotope analysis on deep sea sediment and polar ice cores (Hays et al, 1976; Shackleton, 2000) and the theoretical work by Milankovitch (1920)
Stone line velocities were recorded at 5 glaciers among 20 glaciers regularly monitored for length changes in the Eastern Alps, for example, at the glaciers of Pasterze (Nicolussi and Patzelt, 2001), Vernagtferner (Braun et al, 2012) or Hintereisferner (Span et al, 1997), or in the Western Alps at Rhône Glacier (Mercanton, 1916; Roethlisberger, 1963) or Mer de Glace (Berthier and Vincent, 2012)
This paper presents ice flow velocity records on wellinvestigated mountain glaciers and their relation to other in situ monitoring parameters

Summary

Introduction

The fluctuation of glaciers has become an icon of climate change, after Agassiz (1847) hypothesized the theory of ice ages, which was confirmed by Penck and Brückner (1909) and further substantiated with isotope analysis on deep sea sediment and polar ice cores (Hays et al, 1976; Shackleton, 2000) and the theoretical work by Milankovitch (1920). First monitoring efforts focused on recording the changing positions of glacier termini, starting in the 17th century and systematically organized in the late 19th century, for example by the German and Austrian Alpine Club (Fritzsch, 1898; Groß, 2018). Stone line velocities were recorded at 5 glaciers among 20 glaciers regularly monitored for length changes in the Eastern Alps, for example, at the glaciers of Pasterze (Nicolussi and Patzelt, 2001), Vernagtferner (Braun et al, 2012) or Hintereisferner (Span et al, 1997), or in the Western Alps at Rhône Glacier (Mercanton, 1916; Roethlisberger, 1963) or Mer de Glace (Berthier and Vincent, 2012). At the glaciers Unteraargletscher and Mer de Glace, ice flow was already being measured during the 1840s (Forbes, 1846; Agassiz, 1847)

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Discussion

Conclusion