Glaciers are all individuals!

Between 16 and 11 thousand years ago, the Fennoscandian Ice sheet, which once covered the greater Scandinavia area, collapsed. When coastal ice sheets disappear, they don’t just melt in place.  Rather, the outflow glaciers carry the ice to the sea, where it breaks off and floats away as icebergs, faster than snow in the interior of the ice sheets falls and gets compressed into new ice.  But the details of this process are not understood. As one of the more serious potential consequences of global warming is the collapse of one or more current ice sheets (which would result in several meters of sea level rise), figuring out exactly how ice sheets collapse is kinda important.

Stokes et al. (2014) look at the rate of glacial retreat on the glaciers the carried Fennoscandian ice into the Atlantic Ocean.  Specifically, they looked at eight outflow glaciers in Northern Norway.  These outflow glaciers (not fjords, because the ice is all gone) are all close together, so experienced similar climactic conditions.  What the study found was that despite similar forcing, the glaciers experienced very different responses, and all retreated at different speeds and times. This shows that glacial dynamics cannot be predicted based on local climactic conditions, without also accounting for local topography, bathymetry, and ice flow. 

The reason this is important is that many current glaciers in Greenland and the Antarctic Peninsula are retreating even faster than these glaciers did at the end of the last ice age.  And this paper shows that our current predictive tools are inadequate to tell us how fast outflow glaciers retreat, even when subjected to similar conditions. Individual glaciers, it seems, all react in their own peculiar way.

Asynchronous response of marine-terminating outlet glaciersduring deglaciation of the Fennoscandian Ice Sheet