How
do
glaciers flow?
Photo: Jakobshavn Isbræ in West Greenland by Konrad Steffen
On the previous page, we learned that glacial flow depends on how much stress and strain a glacier experiences.
A simple mathematical law known as Glen's Flow Law puts this all together:
ε = Aτ^n,
where ε is the strain rate, A is a constant related to the temperature of ice, τ is the shear stress,
and n is another constant with an average value of ~3.
Because of the way crystals of ice form, they have very weak bonds perpendicular to their "c" axis
(looking down in map view).
Imagine a stacked deck of cards: after you apply enough force down onto them,
they will flatten out and move sideways. Some may even slip past each other faster than others.
This same process goes on inside glaciers and can result in quite complicated internal deformation structures!
1. What is a glacier?
2. Stress and Strain
3. How do glaciers flow?
4. Basal Sliding
Bibliography