Estimation of absolute water content in Spitsbergen glaciers from radar sounding data

Abstract

Field data available on radio-wave velocities and power reflection coefficients from the cold/temperate ice boundary have been used to estimate the absolute water content and its variations in the temperate ice of two-layered galciers on Spitsbergen. The data have been interpreted with certain assumptions concerning radio-wave propagation and reflection models. The study shows that in cold periods, the average total water content in the upper part of the temperate ice varies in different glaciers from 2.8 to 9.1%. Macro inclusions might contain the major part of the total water content volume. Within one glacier, the spatial variability of water content in the upper part of the temperate ice varies in different galciers from 2.8 to 9.1%. Macro inclusions might contain the major part of the total water volume. Within one glacier, the spatial variability of water content in the upper part of the temperature ice is 1.7 - 11.9%. Seasonal variation of the total water content in the temperate layer reaches 2.3% (from 0.1% in spring to 2.4% in summer). Water content distribution with depth can vary: either it has a maximum up to 5.0% (even in spring) in the upper 30–60 m of the temperate ic, then decreases downward: or it is more uniform. Water content in the upper part of temperate ice and bedrock reflection coefficients reveal a rather close relation with surficial melting rate at the ELA and with ice facies zones. Water storage in the temperate layer is enough to feed englacial run-off during the whole cold period.