Fluctuations of Glaciers (FoG)

Since the beginning of internationally coordinated systematic observations on
glacier variations in 1894, a valuable and increasingly important data basis on
glacier changes has been built up. In 1986 the World Glacier Monitoring Service
(WGMS) started to maintain and continue the collection of information on
ongoing glacier changes, when the two former ICSI services PSFG (Permanent
Service on Fluctuations of Glaciers) and TTS / WGI (TemporalTechnical Secretary
/ World Glacier Inventory) were combined. The tasks of the WGMS are to
continuously upgrade, collect and periodically publish glacier inventory and
fluctuation data as well as to include satellite observations of remote
glaciers and to assess ongoing changes.

The WGMS database stores two types of data: 1) The World Glacier Inventory
(WGI) contains glacier data describing the spatial distribution and 2) The
Fluctuations of Glaciers (FoG) and Mass Balance Bulletin (MBB) contains data
documenting changes in time (changes in mass, volume, area and length of
glaciers).Today, the World Glacier Monitoring Service (WGMS) collects
standardized observations on changes in mass, volume, area and length of
glaciers with time (glacier fluctuations), as well as statistical information
on the distribution of perennial surface ice in space (glacier inventories).
Such glacier fluctuation and inventory data are high priority key variables in
climate system monitoring; they form a basis for hydrological modelling with
respect to possible effects of atmospheric warming, and provide fundamental
information in glaciology, glacial geomorphology and quaternary geology. The
highest information density is found for the Alps and Scandinavia, where long
and uninterrupted records are available.