Showing papers by "Viktor Kaufmann published in 2015"

Velocity Changes of Rock Glaciers and Induced Hazards

Abstract: Recent observations and geodetic measurements in the European Alps show that changes are occurring on rock glacier dynamics, ranging from moderate velocity variations to strong acceleration or even total collapse. These changes can be related to the ground temperature and to climate warming. In most cases, rock glaciers do not represent any serious hazard, except the instability of their surface and local rockfalls at the steep front. The surface movements, though moderate, can nevertheless cause damages to sensible infrastructures like cableways or buildings, if these are not designed to adapt to surface movements. The strong accelerations observed on some rock glaciers, however, induce a change of magnitude, and may threaten in some cases downslope areas. Thus, the presence of active or inactive rock glaciers with high ice content must be considered not only with regard to present conditions and dynamics, but with respect to possible evolutions due to climate change.

Glaciological Studies at Pasterze Glacier (Austria) Based on Aerial Photographs

Abstract: This chapter describes and analyses glacier recession observed at Pasterze Glacier, Hohe Tauern Range, Austria, for the time period 2003–2009. Pasterze Glacier is the largest glacier of the entire Eastern Alps, and it is highly indicative of ongoing glacier melt in the Alps. We evaluated three glacier stages (2003, 2006 and 2009) and the glaciological changes between them. The quantitative analysis is based on aerial surveys carried out during the summer of these years. The photogrammetric workflow provided high resolution datasets, such as digital elevation models and orthophotos of each stage. We evaluated the extent, surface elevation, flow velocity field, supraglacial debris cover, and geomorphological changes at the glacier surface and the adjacent paraglacial environment. The main numerical results can be summarized as follows: the glacier covered 17.3 ± 0.1 km2 in 2009, the mean surface elevation change was −1.31 ± 0.07 m a−1 for the period 2003–2009, the glacier surface flow velocity in two test areas at the glacier tongue decelerated from 2003–2006 to 2006–2009 (−4 % and −31 %), and the debris cover of the glacier tongue increased from 63 % (2003) to 72 % (2009). We conclude that Pasterze Glacier is far from equilibrium and that its glacier tongue will turn into a large dead ice body in the near future.