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Language & WorldFact

The prime meridian isn't where the line in Greenwich is.

Tourists stand on the brass prime-meridian line in Greenwich. Your GPS there reads 0.0015° West, though. The modern reference meridian runs about 102 metres east, through the park. The reason: in the 19th century the observatory aligned its instrument with a plumb line, which local gravity deflects slightly. Satellites measure from Earth's centre instead.

Useful: For a photo with your foot on 0°, walk to the bin in the park, not the line.

Source: en.wikipedia.org

GeografieGpsGreenwich

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Question on this card

How far is the GPS prime meridian from the Greenwich line?

  1. About 1 metre
  2. About 102 metres
  3. About 1 kilometre
  4. They are identical
Show the answer

Correct: About 102 metres

The IERS Reference Meridian runs about 102 metres east of the historic line.

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