Asked by Johny
Glacier volume and glacier mass balance are inextricably linked. Changes in glacier mass balance will cause a change in glacier length and volume. Glacier mass balance is very labour intensive to measure accurately in the field. It takes a lot of work in man-hours to accurately measure accumulation and ablation across a whole glacier, and to repeat this every season. There are therefore not that many glaciers with accurate, long-term measurements of surface mass balance. For this reason, scientists may use the simpler method of measuring volume and area change from satellite images to infer broader, regional glacier behaviour. This is useful, because glaciers are often affected by non-linear processes, and so analysing more regional volume / area change could be a better analysis of climate change.
However, the time taken for a glacier’s volume to readjust to a change in surface mass balance is the response time. A glacier may take some time to readjust to a change in climate. So long-term mass balance measurements may provide a more immediate indication of a glacier’s health.
In summary, glaciologists use both methods – volume change and surface mass balance change – to assess the affect of climate change on glaciers.