Studia Geophysica et Geodaetica

, Volume 21, Issue 2, pp 107–117 | Cite as

The rotation of the earth between 1955.5 and 1976.5

  • Jan Vondrák
  • M. Burša


The difference between the rotational time UT1 and atomic time scale AT was analysed in order to find the secular and periodic variations in the rotational velocity of the Earth. It was found that the length of the mean solar day was increasing by 12.8 ms per century in the interval discussed. As a whole, eleven periodic terms were found, the most significant having the periods of 0.5, 1.0, 6.7 and 11.9 y. The correlation between the long period changes in the Earth's rotation and relative sunspot numbers is shown.


Structural Geology Rotational Velocity Sunspot Number Periodic Variation Period Change 
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Copyright information

© ACADEMIA, Publishing House of the Czechoslovak Academy of Sciences 1977

Authors and Affiliations

  • Jan Vondrák
    • 1
  • M. Burša
  1. 1.Research Institute of Geodesy, Topography and CartographyPrague

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