Calving localization at Helheim Glacier using multiple local seismic stations

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in The Cryosphere 11 (2017): 609-618, doi:10.5194/tc-11-609-2017.A multiple-station technique for localizing glacier calving events is applied to Helheim Glacier in southeastern Greenland. The difference in seismic-wave arrival times between each pairing of four local seismometers is used to generate a locus of possible event origins in the shape of a hyperbola. The intersection of the hyperbolas provides an estimate of the calving location. This method is used as the P and S waves are not distinguishable due to the proximity of the local seismometers to the event and the emergent nature of calving signals. We find that the seismic waves that arrive at the seismometers are dominated by surface (Rayleigh) waves. The surface-wave velocity for Helheim Glacier is estimated using a grid search with 11 calving events identified at Helheim from August 2014 to August 2015. From this, a catalogue of 11 calving locations is generated, showing that calving preferentially happens at the northern end of Helheim Glacier.The authors acknowledge the support of the Arctic Division of the Office of Polar Programs under grants ARC-0806393 and ARC-1304137