Suretta Sud Glacier - Servizio Glaciologico Lombardo

2008 glaciological
Survey
The terminus variations The sample glaciers of Italian Glaciological
Committee (CGI)
Some glaciers subject to a complete survey have their linear terminus variations measured.
The algebraic symbol indicates a downvalley advance (+) or an upvalley withdrawal (-). The
variation is not directly linked to the snow-meteorological trend of the season. Many are the
additional factors (such as: glacier response time, bedrock morphology, flux velocity, etc…)
that make this parameter of little use in evaluating the state of the glacier in the survey year.
However these glaciers carry an historical series of linear front measurements, which makes
their continuous monitoring extremely interesting. Our glaciers, along with other Italian glaciers,
are part of the historical sample of ice bodies surveyed by CGI. The sample is divided
into two sets. Groups 1 and 2, selected on the basis of their glaciological importance and
representativeness, include the glaciers measured once a year; group 3 include the glaciers
measured on a rotational basis, generally once every 5 years. In the present phase of significant
and prolonged decrements, the front measurements are coherent with the dynamic
index: out of the 26 glaciers with annual measurement, only 1 has held its previous position;
all the others have shown sometimes consistent shrinkages. The Passo di Chiareggio
and Verva Maggiore Glaciers multi-year decrements were paroxysmal and caused by the
dismemberments of dead-ice blocks, a typical feature of an intense withdrawal phase.
Tab. 8: Summary of terminus measurement data, versus 2007 and previous years.
Variations versus 2007 decrements increments unchanged
26 25 (96,2 %) 0 1 (3,8 %)
Variations versus previous years decrements increments unchanged
3 3 (100 %) 0 0
Fig. 7: The terminus variations of the Lombardy’s sample glaciers over the last 18 years.
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