Damma Glacier - Switzerland

The site is located in the Central Alps, in the canton of Uri, Switzerland. it encompasses the the Damma glacier and its fore field, which is located at an altitude between 1950 and 2050 m above sea level. Due to the glacier retreat a soil chronosequence of about 150 years is present in the valley bottom. The soil chronosequence has been the object of extensive studies. The climate is characterized by a short vegetation period (late June to mid October), and about 2400 mm precipitation per year. The bedrock is composed of a coarse-grained granite of the Aare massif, which was metamorphosed under greenschist facies conditions and is composed of quartz, plagioclase, potassium feldspar, biotite, and muscovite. Epidote is present in significant amounts, mainly as inclusion in plagioclase. Additional accessory minerals include magnetite chlorite and apatite. Although different varieties of metagranite, distinguished mainly by variations in the relative mineral proportions and grain size, are present in the catchment, the composition of the bedrock is very similar everywhere along the soil chronosequence. The front of the northeast-exposed Damma glacier has retreated at an average rate of approximately 10 m yr−1 since the beginning of systematic annual measurements in 1921, culminating in 2003 with the disconnection of a dead-ice body, a large block of stagnant ice detached from the main glacier remaining in the valley. The active glacier currently terminates above a steep wall at the valley head. Field instrumentation includes a meteorological station, a runoff station of the main river, and groundwater tubes to monitor river-groundwater exchange.