Estimation of glacier volume and volume change by scaling methods
While difficult to measure directly, glacier volume can be more easily approximated by measuring surface area and applying a power-law scaling relationship. The volume– area scaling relationship has been predicted and well established from field data, theory, and numerical modeling. As a glacier changes size, the consequent changes in glacier volume also can be estimated and predicted by derivations from the same volume–area relationship. Summing such changes over all the world’s glaciers gives a convenient measure of global changes in sea level.
Bahr, David B., "Estimation of glacier volume and volume change by scaling methods" (2011). Regis University Faculty Publications (comprehensive list). 835.