Coastal & Marine Geology InfoBank

Home FACS Activities Atlas Geology School Related Sites More

USGS CMG InfoBank: Glacial Flow

Skip navigational links
Dictionaries: Our Mapping Systems   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   digital data   formal metadata   lines   metadata   NGDC   port stops   project/theme   region   ship   stations   time   virtual globe   year  
Data Types: bathymetry   biological   geochemical   gravity   ground penetrating radar   imaging   LIDAR   logs   magnetics   metering equipment   navigation   samples   seismic   total station   definitions disclaimer  
Data Formats: ARC coverage   E00   FGDC metadata   gridded/image   imaging   material   scattered/swath   Shapefile   vector/polygon  
Comment: 05:25 - 06:38 (01:13)
Source: Annenberg/CPB Resources - Earth Revealed 23. Glaciers
Keywords: "Louis Agassi", "James Zumberge", glacier, "glacial flow", glaciologist, drilling, Swiss, friction, creep, bedrock, "basal slip", "glacial melt", snout

Our transcription: Scientists like Agassi also wanted to understand how glaciers flow internally.
But it wasn't until early in the post World War II era that glaciologists were able to drill a hole through a Swiss glacier.
This was a hole several hundred meters deep, maybe a couple of inches in diameter or smaller, but they put an aluminum tube in that hole right down to the bottom of the glacier.
The scientists discovered that the tube bent as it shifted down-slope.
So just as friction slows movement of ice at the sides of glaciers, it slows movement at the base as well.
Scientists also discovered that glaciers not only creep over the bedrock, but in places break free to glide across it.
Such basal slip is lubricated by water melting from the ice.
Streams of this sub-glacial melt water commonly pour from the snouts of glaciers.

Geology School Keywords
Skip footer navigational links

Coastal and Marine Science Centers:  Pacific   St. Petersburg   Woods Hole  
InfoBank   Coastal and Marine Geology Program   Geologic Information   Ask-A-Geologist   USGS Disclaimer  

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: InfoBank staff
Page Last Modified: Thu Oct 31 04:27:45 PDT 2013  (chd)