Calving localization at Helheim Glacier using multiple local seismic stations
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....
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-02-01
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| Series: | The Cryosphere |
| Online Access: | http://www.the-cryosphere.net/11/609/2017/tc-11-609-2017.pdf |
| Summary: | 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 <i>P</i> and <i>S</i> 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. |
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| ISSN: | 1994-0416 1994-0424 |