The Svalbard archipelago is covered by glaciers and ice caps to 57% of its 60,000 km2 land area, corresponding to approximately 6,200 km3 of ice. The initial scope of the network is to study the Kongsvegen glacier located near the Ny-Ålesund research station. This glacier rests on a sediment base of 5 to 60 m thickness, is grounded below sea level over its lowermost 6 km and has a polythermal regime with a 50-130m thick cold layer on top of temperate ice. On its lateral flanks, the glacier is frozen to the bed, which presumably exerts considerable lateral flow resistance. Following the a previous surge in 1948, the glacier has been in its quiescent stage, building up a reservoir of ice in its upper part because of the inefficient downstream transport of ice.
In 2018, we operated three three-component seismometers positioned along 13 km of the central flowline between the glacier front and the long-term equilibrium line altitude. In 2021, this network has been expanded and we operated up to 20 seismometers of which 18 were deployed at the surface (i.e. 1.5 m into the ice to prevent melt-out and loss of connection during the melt season) and two were installed into boreholes, ca. 78 m above the glacier bed (262 m beneath the surface) and ca. 86 m above the glacier bed (263 m beneath the surface). Surface seismometers are 4.5 Hz sensors and we used HG-6 OB 14 Hz 375 sensors in the boreholes; data recording of all sensors has been accomplished using DiGOS DATA-CUBE3s sampled at a frequency of up to 800 Hz.
The network will be maintained on Kongsvegen glacier, and likely extended to other surging glaciers.