Abstract
Internal ice strain rates have been measured along two boreholes drilled through Glacier de Tsanfleuron, Switzerland. Differences between these measurements and the output from a 3D numerical model of glacier motion have been minimized by a scheme that optimizes three rheological parameters in the constitutive equation for ice creep: the stress exponent n, the rate factor A, and a Lower Zone (basal ice) enhancement factor E-LZ. Results suggest that a linear rheology dominated by diffusion creep (n = 1) is more appropriate for modelling ice flow in this relatively thin (generally < 80 m thick) glacier than the conventional n = 3, and that E-LZ is similar to 2. For n = 1, the predicted ice crystal size and value of E-LZ are both consistent with measurements made on ice cores recovered from the glacier, providing independent support for the optimization technique and the linear creep model.
| Original language | English |
|---|---|
| Article number | L12502 |
| Pages (from-to) | 1-5- |
| Number of pages | 5 |
| Journal | Geophysical Research Letters |
| Volume | 35 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 19 Jun 2008 |
Keywords
- DEVIATORIC STRESS
- WATER-CONTENT
- GLACIER
- SWITZERLAND
- TSANFLEURON
- VELOCITY