WORLD GLACIER INVENTORY - EXTENDED FORMAT (WGI-XF)
Data
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The World Glacier Inventory (WGI) was conceived half a century ago as an activity to be completed during the International Geophysical Year, 1957-1958. It consists today of nearly 70 000 glacier records, housed at the National Snow and Ice Data Center, Boulder (
WGI-NSIDC) and covering slightly less than one quarter of the glacier ice outside the ice sheets. Evidently a complete WGI must be a compromise if it is to be available and usable soon.
A more complete version, called WGI-XF, is available here. As of September 2008 it contains records for 131 400 glaciers and nearly half of the global extent of ice. The additional glaciers come mainly from the assimilation of existing regional inventories but also from rescuing inventories that have been lost and from new inventories in Canada and the Subantarctic.
WGI-XF is contained in a plain-ASCII, sequential-access file with one record per glacier and 54 fixed-width data fields
per record. A version in comma-separated-value format is also available (see below).
Right: Status of the WGI, 2008. Numbers (cumulative at left side) are extents in thousands of sq. km.
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Format
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In WGI-XF, the XF stands for "extended format", flagging the fact that WGI-XF conforms to a set of explicit specifications which enhance usefulness by eliminating low-level inconsistencies. Two important features are nominal glaciers and glacier complexes. A nominal glacier, of which there are about 5 000 in WGI-XF, is one about which little is known other than its existence and approximate location. A glacier complex is one or more contiguous glaciers. This term embodies the idea, which is not new, that inventories can be preliminary, based upon vector outlines which await subdivision into individual glaciers. At present there are about 1 800 glacier complexes in WGI-XF.
The format of WGI-XF is specified in detail by Cogley (2005).
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A comma-separated-value version of WGI-XF may be downloaded here.
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References
Cogley, J.G., 2005, Extended Format for the World Glacier
Inventory, Trent Technical Note 2005-1, Department of Geography, Trent
University, Peterborough, Ontario, Canada. Revised September 2008.