Original paper

Paraglacial processes on the glacier foreland of Vernagtferner (Ötztal Alps, Austria)

Jäger, Daniel; Winkler, Stefan


Paraglacial processes in the glacier foreland of Vernagtferner in the Ötztal Alps of Austria were studied. The work primarily analyses the prominent lateral moraines and associated paraglacial processes there such as mass movements and formation and development of gullies or gully-like channels. A special focus was set on the examination of former hypotheses of gully formation depending on slope gradients, sediment thickness, matrix granulometry and sediment packing, which were developed mainly in the Skandes of Norway and have not been commonly used in alpine glacier forelands. In order to obtain comparable results, investigations were based on methods established in those studies such as analyzing gully density, slope angle, grain size distribution etc. Furthermore, measurements of current erosion rates and geomorphologic mappings were applied. The results revealed that numerous factors influence lateral moraine dynamics and the development of gullies. Similarities to former hypotheses of gully formation e.g., from western Norway, could be drawn as well. In addition to a certain slope gradient, the amount of accumulated till seems to be the most important factor. Beside them, composition and packing of sediments is likely to influence the occurrence or absence of gullies in the study area. Our work also contains investigations from other paraglacially active areas of the foreland, in order to provide a more complete overview of the activities there. These studies were mainly focused on photographic comparisons of the situation of 1991 and 2008. However, even in this short period of time, some significant changes, like in the drainage pattern, could be detected.


paraglacial processesgully developmentglacier forelandlateral morainesvernagtfernerÖtztal alps