Measuring the Elastic Modulus of Snow. Issue 21 (14th November 2017)

• Record Type: Journal Article
• Authors: Gerling, B.; Löwe, H.; van Herwijnen, A.
• Is Part Of: Geophysical research letters. Volume 44:Issue 21(2017)
• Page Start: 11, 088
• Page End: 11, 096
• Publication Date: 2017-11-14
• Subjects: Snow -- Elastic modulus -- Wave propagation -- X‐ray tomography -- Finite Element Method; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL075110
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: The elastic modulus is the most fundamental mechanical property of snow. However, literature values scatter by orders of magnitude and hitherto no cross‐validated measurements exists. To this end, we employ P wave propagation experiments under controlled laboratory conditions on decimeter‐sized snow specimen, prepared from artificial snow and subjected to isothermal sintering, to cover a considerable range of densities (170–370 kg m −3 ). The P wave modulus was estimated from wave propagation speeds in transverse isotropic media and compared to microstructure‐based finite element (FE) calculations from X‐ray tomography images. Heterogeneities and size differences between acoustic and FE sample volumes were characterized by SnowMicroPen measurements, yielding an elastic modulus as a by‐product. The moduli (10–340 MPa) from the acoustic and FE method are in very good agreement ( R 2 =0.99) over the entire range of densities. A remaining bias (24 %) between both methods can be explained by layer heterogeneities which systematically reduce the estimates from the acoustic method. Key Points: First cross‐validated measurements of the elastic modulus of snow Agreement between estimates from P wave propagation and finite element calculations A remaining bias between both methods is related to effects of random layering