Snow depth is measured using GeoRadar along the SNM transect running in the valley floor of the Zackenberg valley. Measurements are primarily conducted by end of winter, before snow melt is initiated. Positions are given in UTM coordinates (WGS 84, UTM Zone 27 N). Systematic measurements with GeoRadar were implemented in the GeoBasis snow monitoring in 2016. The measured two-way travel time is used to estimate the snow depth by relating this to manual measurements of the snow depth performed along the transect. From linear relationships between the manually measured depths and the travel time, an approximated velocity is found and the snow depth estimated from depth = velocity * one way travel time. For all transects the two way travel time, manual measurements, the approximated velocity and estimated snow depth is recorded alongside the coordinates and information regarding the frequency of the antenna used. Snow properties:Snow properties GeoBasis Zackenberg:The GeoBasis monitoring programme focuses on selected abiotic characteristics in order to describe the state of Greenlandic terrestrial environments and their potential feedback effects in a changing climate. Monitored plot data is up-scaled to a landscape level and is used to improve ecosystem models to be able to quantify these feedback mechanisms. The GeoBasis programme provides an active response to recommendations in international assessments such as ACIA and SWIPA; and is continuously being adapted based on AMAP and other international founded recommendations. Furthermore, the GeoBasis programme is directly involved in several international networks and research projects (e.g. the Circumpolar Active Layer Monitoring (CALM) programme, the Nordic Centre of Excellence DEFROST, the Danish Centre of Excellence CENPERM, the EU-projects PAGE21 and INTERACT, and the Arctic Research Centre at Aarhus University). The GeoBasis programme is divided into a number of sub-groups, including:
