Publication Date:
2019-07-17
Description:
Two seismic surveys were carried out on the high-altitude glacier saddle, Colle Gnifetti,
Monte Rosa, Italy/Switzerland. Explosive and vibroseismic sources were tested to explore the best way
to generate seismic waves to deduce shallow and intermediate properties (〈100 m) of firn and ice. The
explosive source (SISSY) excites strong surface and diving waves, degrading data quality for processing;
no englacial reflections besides the noisy bed reflector are visible. However, the strong diving waves are
analyzed to derive the density distribution of the firn pack, yielding results similar to a nearby ice core.
The vibrator source (ElViS), used in both P- and SH-wave modes, produces detectable laterally coherent
reflections within the firn and ice column.We compare these with ice-core and radar data. The SH-wave
data are particularly useful in providing detailed, high-resolution information on firn and ice
stratigraphy. Our analyses demonstrate the potential of seismic methods to determine physical
properties of firn and ice, particularly density and potentially also crystal-orientation fabric.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
