Coastal & Marine Geology InfoBank

Home FACS Activities Atlas Geology School Related Sites More

USGS CMG InfoBank: Glacial Evidence In Geology

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: 01:38 - 02:33 (00:55)
Source: Annenberg/CPB Resources - Earth Revealed 23. Glaciers
Keywords: "James Sadd", glacier, geologist, "Louis Agassi", Europe, sediment, boulder, "glacial advance", "glacial retreat", "sedimentary rock", continent, "Northern Hemisphere", "glacial ice", "landscape evolution", "glacial melt"

Our transcription: Early scientists didn't really appreciate the important geological role of glaciers.
Even geologists were convinced that glaciers had never existed outside of their present locations over the last one million years.
A breakthrough came in 1836 when Swiss scientist, Louis Agassi, reported evidence that the inhabitance of medieval villages in Europe had moved their towns to keep pace with advancing glaciers.
Further study revealed that glaciers leave behind a distinctive deposit of sediment like these boulders as they melt back and retreat.
Geologically recent examples of these sedimentary deposits, found hundreds of kilometers from the nearest glacier, demonstrated to Agassi that vast portions of the continents of the Northern Hemisphere had been recently covered with glacial ice.
Observations like these led to the realization that glaciers are active and powerful agents of landscape evolution.

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 04:27:44 PDT 2013  (chd)