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What Is the Geoid?
This reference provides an introduction to the geoid, the equipotential surface of the Earth's gravity field which best fits global mean sea level. There is a narrative of early attempts to describe the geoid, and schematic diagrams showing the geoid and its relationship to Earth's crust, local mean sea level, orthometric heights, and local dynamic ocean topography.
Intended for grade levels:
  • High (9-12)
  • College (13-14)
Type of resource:
  • Visual:
    • Illustration - scientific
  • Text:
    • Ref. material
  • Geological Sciences:
    • Geophysics
Technical requirements:
No specific technical requirements, just a browser required
Cost / Copyright:
No cost
Copyright and other restrictions information are unknown.
DLESE Catalog ID: EARTHQUAKE-000-000-010-104
Resource contact / Creator / Publisher:
Contact: Dr Dan Roman
Geoid and Gravity Team
National Geodetic Survey (NGS)

Publisher: National Oceanic and Atmospheric Administration (NOAA)
National Geodetic Survey (NGS)