Monthly average polar sea-ice concentration 1978 through 1991

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Description This data set represents the results of calculations carried out on sea-ice-concentration data from the SMMR and SSM/I instruments. The original data were obtained from the National Snow and Ice Data Center (NSIDC). The data set also contains the source
Originators Schweitzer, Peter N.
Publication U.S. Geological Survey Digital Data Series DDS-27

Related topics

States or counties

Overview of attributes

Labels of the mapped units described by polygons in the data
set are as follows:
Each line object in the fault coverage has one of four attribute
1) faults (label FAULT)
2) dashed fault (label DASH)
3) dotted fault (label DOT)
4) hidden contact (label CONTAC)
Full details of the meanings of the attributes are given in USGS
Professional Paper 901, whose text is provided with this data set.

U.S. Geological Survey Professional Paper 901 is included with this data set (when distributed in CD-ROM format) in ASCII, with figures in TIFF.

Geologic unit

Bedrock formations that are, wherever possible, time-stratigraphic--that is, units which are approximately the same geologic ages at all places, such as systems, series, and stages.

Label Definition


Faults are shown not only to explain offsets of map units, but for their own sake, to express the structural grain of the area. The density of faults represented on the geologic map thus equals that which would appear on a tectonic map of the country, but they are marked simply as faults, not as low-angle or high- angle thrust faults, normal faults, or strike-slip faults; for this information the user should consult the appro- priate tectonic map.

Label Definition