Articles | Volume 11, issue 1
The Cryosphere, 11, 609–618, 2017
The Cryosphere, 11, 609–618, 2017

Research article 22 Feb 2017

Research article | 22 Feb 2017

Calving localization at Helheim Glacier using multiple local seismic stations

M. Jeffrey Mei1,2, David M. Holland3, Sridhar Anandakrishnan4, and Tiantian Zheng5 M. Jeffrey Mei et al.
  • 1Department of Applied Ocean Science and Engineering, Woods Hole Oceanographic Institution, MA 02540, USA
  • 2Department of Mechanical Engineering, Massachusetts Institute of Technology, MA 02139, USA
  • 3Courant Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, NY 10012, USA
  • 4Department of Geosciences, Pennsylvania State University, University Park, PA 16801, USA
  • 5Department of Physics, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates

Abstract. 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.

Short summary
We determine a method to locate calving at Helheim Glacier. By using local seismometers, we are able to find the calving location at a much higher precision than previous studies. The signal–onset time differences at four local seismic stations are used to determine possible seismic-wave origins. We present a catalogue of 12 calving events from 2014 to 2015, which shows that calving preferentially happens at the northern end of Helheim Glacier, which will help to constrain models of calving.