Monitoring glacial retreat.

The mass balance of a glacier is the direct link between climate and glacial retreat. The overall mass balance of a glacier is measured to calculate the volume of a glacial mass and glacial run off characteristics. For mass balance measurements, glacier size can range anywhere between 2-5 sq km to ensure accuracy of measurements.

The mass balance of a glacier can be measured through a direct glaciological method where at a number of individual points the change in levels of surface area is measured between two dates (e.g. Summer and winter).

The difference in surface levels between these two dates multiplied by near surface density can then lead to an estimate of the total net mass balance of the glaciers.

Depending on the amount of melted snow and ice, mass balance can be either positive or negative (gain or loss of glacier volume).

Mass balance of a glacier can be measured in variety of ways including geodetic techniques and direct glaciological methods. One of the most frequently used methods for measuring changes in surface levels include drilling wooden stakes into the glacier and snow depths relative to a known surface and then monitoring these points regularly.

However, such measurements need to be carried out regularly on a long-term basis for effective monitoring.