Sounds of the deep: Passive microseismic monitoring of the base of ice streams.

Ice sheets discharge the majority of their mass though fast flowing ice streams and outlet glaciers and the flow dynamics of these features are heavily influenced by conditions at the base. Passive monitoring of microseismic icequake signals generated beneath ice streams are associated with the motion of the ice over its bed and can be used to map both the characteristics of the ice-bed interface and to understand these basal processes. These signals can be inverted for source location, source mechanism and magnitude, amongst other properties, to give spatial and temporal information about the active basal dynamics of a moving ice stream. Since the first dedicated microseismic survey on ice was undertaken in the 1960s, the use of passive microseismic monitoring to investigate the base of ice streams and glaciers has become more commonplace and the utilisation of information contained in these signals …