3. EXTENSIVE INFORMATION
More detailed information about selected glaciers in various mountain ranges, with ongoing direct glaciological mass balance measurements, are presented here, in addition to the summary information contained in the previous chapter. In order to facilitate comparison between the individual glaciers, the submitted material - text, maps, graphs and tables - was standardized and rearranged. The final version of the data presentation was then revised by the national correspondents again.
The text gives general information followed by brief comments on the two reported balance years. General information concerns basic geographic, geometric, climatic and glaciological characteristics of the observed glaciers which may help with the interpretation of climate/glacier-relations. An oblique photograph showing the entire glacier where possible is also included.
Three maps are presented for each glacier. The first one, a topographic map, shows the stake and snow pit network. This network is basically the same from one year to another on most glaciers. In cases with differences between the two reported years, the second one was chosen, i.e., the network from the year 1994/95. The second and third maps are balance maps from the years 1993/94 and 1994/95 respectively, illustrating the pattern of ablation and accumulation distribution. The accuracy of such balance maps depends on the density of the observational network, the complexity of the mass balance distribution and the experience of the local investigators.
A graph of mass balance versus altitude is given for both reported years. The relation between mass balance and altitude or the mass balance gradient is an important parameter in climate/glacier relationships, representing the climatic sensitivity of a glacier and constituting the main forcing function of glacier flow over long time intervals. Therefore, the mass balance gradient near the equilibrium line is often called the activity index of a glacier.
The last two graphs show the relation between the specific net balance and the accumulation area ratio (AAR) and the equilibrium line altitude (ELA) for the whole observation period. The regression equation is given at the top of both diagrams. The AAR regression equation is calculated by integer values only (in percent). AAR values of 0 or 100 % as well as corresponding ELA values outside the altitude range of the observed glaciers were excluded in the regression analysis. Such regressions were used to determine the AAR0 and ELA0 values (cf. Chapter 2). The points from the two reported balance years (1993/94, 1994/95) are specially marked in the plots.
Along with White Glacier (Canadian Arctic) and Peyto Glacier (Canadian Rockies), a new arctic glacier and - for the first time - a glacier from the Rocky Mountains could be included. Vernagtferner was replaced by Hintereisferner. It is planned to alternate these two glaciers.