Glacier Mass Balance and Regime: Data of Measurements and ...

Praviy Aktru275118.0--No 125/Vodop.351.6--Muravlev204314.000.000GL#1,E.Branch1975---GL#1,W.Branch289933.7--Kozelskiy13311.0--Meren-2--0.010Carstenz-21--0.010Table 2.2. Comparisons of annual mass balances measured by topographic methodand determined by glaciological methodGlacier Period Topographic, m/yr Glaciologic, m/yr Difference, m/yr ReferenceStorbreen 1940-97 -0.18 -0.29 0.11 Andreassen, 1999Storbreen 1940-51 -0.4 -0.6 0.2 Andreassen, 1999Storbreen 1951-68 -0.1 -0.3 0.2 Andreassen, 1999Storbreen 1968-84 -0.5 -0.4 -0.1 Andreassen, 1999Storbreen 1984-97 0.2 -0.1 0.3 Andreassen, 1999Alfotbreen* 1969-88 -0.31 0.18 -0.13 Østrem and Haakensen, 1999Hellstugubreen 1968-80 -0.54 -0.45 -0.09 Haakensen, 1986Grasubreen 1968-84 -0.51 -0.41 -0.1 Haakensen, 1986S. Cascade 1970-97 0.81 0.56 0.25 Krimmel, 1999Blue 1957-95 0.37 Conway et al., 1999Djankuat 1968-74 -0.32 -0.35 -0.03 Golubev et al., 1978Careser 1967-90 -0.54 -0.55 -0.01 Giada and Zanon, 1996Gries 1961-79 -0.09 -0.06 0.03 FoG, 1998Gries 1979-86 -0.3 -0.25 0.06 FoG, 1998Gries 1986-91 -1.02 -1.08 0.06 FoG, 1998The examples show that uncertainties between two methods may have signs plus or minus for differentglaciers and for different periods (Storbreen, e.g). Another words, measurements made by glaciologicalmethod give more positive, or more negative balance than by topographic. For some glaciers uncertaintyis very large (Blue, Storbreen) for others are very small (Careser, Djankuat). There are many possibleexplanations discussed in Golubev et al., (1978), Andreassen (1999), Conway et al., (1999), Krimmel(1999), Østrem and Haakensen (1999), and others. The conclusion from these comparisons anddiscussions is that topographic method may serve as the controlling for some glaciers, but may not forothers. Obviously two methods have to be used to get independent data control.44