A comparison of seismic and radar methods to establish the thickness and density of glacier snow cover
2013 (English)In: Annals of Glaciology, ISSN 0260-3055, E-ISSN 1727-5644, Vol. 54, no 64, 73-82 p.Article in journal (Refereed) Published
We show that geophysical methods offer an effective means of quantifying snow thickness and density. Opportunistic (efficient but non-optimized) seismic refraction and ground-penetrating radar (GPR) surveys were performed on Storglaciaren, Sweden, co-located with a snow pit that shows the snowpack to be 1.73 m thick, with density increasing from similar to 120 to similar to 500 kg m(-3) (with a +50 kg m(-3) anomaly between 0.73 and 0.83 m depth). Depths estimated for two detectable GPR reflectors, 0.76 +/- 0.02 and 1.71 +/- 0.03 m, correlate extremely well with ground-truth observations. Refraction seismic predicts an interface at 1.90 +/- 0.31 m depth, with a refraction velocity (3730 +/- 190 m s(-1)) indicative of underlying glacier ice. For density estimates, several standard velocity-density relationships are trialled. In the best case, GPR delivers an excellent density estimate for the upper snow layer (observed = 321 +/- 74 kg m(-3), estimated = 319 +/- 10 kg m(-3)) but overestimates the density of the lower layer by 20%. Refraction seismic delivers a bulk density of 404 +/- 22 kg m(-3) compared with a ground-truth average of 356 +/- 22 kg m(-3). We suggest that geophysical surveys are an effective complement to mass-balance measurements (particularly for controlling estimates of snow thickness between pits) but should always be validated against ground-truth observations.
Place, publisher, year, edition, pages
2013. Vol. 54, no 64, 73-82 p.
Physical Geography Geosciences, Multidisciplinary
IdentifiersURN: urn:nbn:se:su:diva-95097DOI: 10.3189/2013AoG64A044ISI: 000324720300010OAI: oai:DiVA.org:su-95097DiVA: diva2:658550
GLIMPSE project; Leverhulme Trust; Climate Change Consortium of Wales (C3W) Natural Environment Research Council of the UK NE/J500367/1; INTERACT under the European Community's Seventh Framework Programme 262693 2013-10-222013-10-212013-10-22Bibliographically approved