Firn Densification: An Empirical Model
Abstract An empirical model of firn densification from the surface to the zone of pore close-off has been constructed. Fundamental rate equations have been derived for the first two stages of densification. In the first stage, for densities less than 0.55 Mg m −3 , the densification rate is proporti...
| Published in: | Journal of Glaciology |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Cambridge University Press (CUP)
1980
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1017/s0022143000015239 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015239 |
| Summary: | Abstract An empirical model of firn densification from the surface to the zone of pore close-off has been constructed. Fundamental rate equations have been derived for the first two stages of densification. In the first stage, for densities less than 0.55 Mg m −3 , the densification rate is proportional to the mean annual accumulation times the term ( ρ i − ρ ), where ρ is the density of the snow and ρ i is the density of pure ice. The densification rate in the second stage, where 0.55 Mg m −3 < ρ < 0.8 Mg m −3 , is proportional to the square root of the accumulation rate and to ( ρ i− ρ ). Depth–density and depth–age calculations from this model are compared with observation. Model accumulation rates are within about 20% of values obtained by other techniques. It is suggested that depth intervals of constant density in some Antarctic cores may represent a synchronous event in the 1880 ’s when ten times the normal accumulation fell within a year or two. |
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