Satellite imagery collected and analysed over time can be used to assess glacier areas and advance/retreat rates. However, such information only provides partial insights into the health of a glacier. It is possible for a glacier to be advancing, extending further down a slope over time, and also thinning simultaneously such that the overall glacier volume remains unchanged. To fully assess stored water resources and/or the changes in water storage in glaciers over time, both glacier area and volume, generally referred to as glacier mass balance, are required.
The current status of benchmark glaciers and their responses to climatic variations are assessed through