Convert fathom (US survey) to Earth polar radius Online | Free Length Converter

Fathom (US Survey)

The fathom (US survey) is a unit of length used in U.S. surveying and nautical contexts, defined as exactly 6 US survey feet. Since one US survey foot is approximately 0.3048006096 meters, the US survey fathom measures about 1.828804 meters.

Like the international fathom, it is primarily used to measure water depths and underwater distances in marine navigation and surveying.

Key details:

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  1 US survey fathom = 6 US survey feet

  
  
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  1 US survey fathom ≈ 1.828804 meters

  
  
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  1 fathom = 2 yards

  
  

Though the difference between the US survey fathom and the international fathom is very small, the US survey units are being phased out in favor of international standards, but they still appear in some legal and historical surveying documents.

Earth Polar Radius

The Earth's polar radius is the distance from the center of the Earth to the North or South Pole. It measures the Earth’s radius along its rotational axis.

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  Its value is approximately 6,356.8 kilometers (about 3,949.9 miles).

  
  
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  The Earth is an oblate spheroid, so the polar radius is slightly shorter than the equatorial radius due to the planet's flattening at the poles.

  
  
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  This measurement is crucial for geodesy, understanding Earth’s shape, and satellite navigation.

  
  

Key facts:

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  Polar radius ≈ 6,356.8 km

  
  
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  Smaller than equatorial radius by about 21.3 km

  
  
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  Important for precise Earth modeling and mapping

  
  

The difference between the polar and equatorial radius reflects the Earth’s rotation and its effect on the planet’s shape.