The Athabasca Glacier in Jasper National Park, Alberta, Canada, is one of the most popular tourist destinations in the province and the most visited glacier in North America. The glacier has been retreating since 1843, and the Alberta tourist bureau is concerned that if the retreat continues, it won’t be long before there is no longer a glacier to visit. The photographs show the glacier 100 years apart; the photos are taken from the same location. In the 2006 photo, the glacier is only in the far left portion of the photo (right above “2006”). The map shows the location of the terminus at different times from 1843-1999. The final photo at the bottom shows a recent (2010) photo; the glacier in this view is ~6.2km from the head to the terminus.

You have been asked to advise the tourist bureau and National Parks Canada on how much longer the glacier will be a tourist attraction.

a. Although the terminus is not a straight line, but follows topography, measure the rate of retreat from 1843-1999 along the red dashed line on the map (v = d/t). Make sure you are in metric.
b. Has the rate of retreat been constant? To determine this, measure the rate of retreat along the same line, first from 1843-1906, and second, from 1906-1999.
c. Next, for each of these rate estimates, ascertain how long it will be before the glacier disappears (remember, it is 6.2km long in 2010). Make sure you are in the correct units! (Divide 6.2km by the 3 rates previously determined.)