Coastal & Marine Geology InfoBank

USGS CMG InfoBank: Age of Ice


Dictionaries:	The USGS and Science Education USGS Fact Sheets Topics Keywords Data Dictionary Metadata Dictionary Computer Terminology Digital Formats
InfoBank Terms:	Activity ID activity overview crew formal metadata lines metadata NGDC port stops project/theme region ship stations time virtual globe year
Data Types:	bathymetry geodetic positioning gravity ground penetrating radar imagery LIDAR magnetics metering equipment navigation samples seismic definitions disclaimer
Data Formats:	ARC coverage E00 FGDC metadata gridded/image imaging material scattered/swath Shapefile vector/polygon

Comment: 20:38 - 21:09 (00:31)

Source: Annenberg/CPB Resources - Earth Revealed 23. Glaciers

Keywords: Greenland, "ice core", drilling, "geologic age", season, "carbon-14 dating", glacier, "glacial ice", "Greenland Ice Core Program"

Our transcription: The cores from Greenland date back over 100,000 years.

The age of the ice is determined by counting bands which form seasonally.

High-density ice bands are typical of winter months; low density of summer.

In deep ice the bands are compressed together making them impossible to see, so chemical methods including Carbon-14 dating are used instead to determine the age of the ice.

Geology School Keywords

Skip footer navigational links

InfoBank Menlo Park & Santa Cruz Centers St. Petersburg Center Woods Hole Center Coastal and Marine Geology Program Geologic Information Ask-A-Geologist USGS Disclaimer

Accessibility FOIA Privacy Policies and Notices

U.S. Department of the Interior | U.S. Geological Survey
URL: http://walrus.wr.usgs.gov/infobank/programs/html/school/moviepage/21.01.21.html
Page Contact: InfoBank staff
Page Last Modified: Tue Dec 16 06:32:25 PST 2008 (wcs)

Accessibility FOIA Privacy Policies and Notices
U.S. Department of the Interior \| U.S. Geological Survey URL: http://walrus.wr.usgs.gov/infobank/programs/html/school/moviepage/21.01.21.html Page Contact: InfoBank staff Page Last Modified: Tue Dec 16 06:32:25 PST 2008 (wcs)