Time-lapse may not be the most complex of visual capture techniques in this digital age, but it does effectively highlight the change of glaciers over time. “Seeing is believing”, the tagline used by the recently established Extreme Ice Survey. This exciting and revealing project was started by James Balog, once a doubter of climate change, and aims to show the world the effects of a warming climate by taking time-lapse photography into extreme locations.
A common misunderstanding with glacier retreat is that the body of ice literally moves backwards up a valley. You can see from the above time-lapse video that in fact the glacier continues to flow forwards (as a solid mass much slower than liquid water) even though the front of the glacier retreats. This is a result of the glacier snout melting (and calving to produce icebergs when floating on water) at a greater rate than snow can fall and be compressed into ice at the glacier’s upstream end.
It is also worth a mention that the flow behaviour and retreat of a glacier is influenced by the land it moves through and the undulating rock it flows over, changes in sea level and sea temperature it may float into, amount of lubricating meltwater it produces and internal dynamics of the ice, in addition to the climate (which may have a different local pattern to the global trend). Therefore it is obviously important to understand these varied factors for different styles of glacier and in a range of regions. Glaciers provide a great indication of the climate when compared from all around the planet (see World Glacier Monitoring Service’s report) and hold significance for future sea level rise as well as a water resource.