Open AccessRe‐determination of the decade fluctuations in the rotation of the Earth in the period 1861‐1978
Author(s) -
Morrison L. V.
Publication year - 1979
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1979.tb01029.x
Subject(s) - earth's rotation , ephemeris , geodesy , rotation period , rotation (mathematics) , universal time , solid earth , figure of the earth , mantle (geology) , earth (classical element) , polar motion , day length , period (music) , geology , physics , geophysics , stars , atmospheric sciences , astronomy , mathematics , geometry , satellite , medicine , photoperiodism , acoustics
Summary The ‘decade’ fluctuations in the Earth's rate of rotation are derived from a comparison of the universal time‐scale, based on the Earth's diurnal rotation, with: (a) the dynamical time‐scale of the lunar ephemeris from 1861 to 1955 (using the collected times of occultations of stars), and (b) the international atomic time‐scale from 1955 to 1978. It is concluded from these fluctuations that the torques which operated on the Earth's mantle varied in magnitude in a characteristic period of about 30 yr and reached a maximum of 10 18 Nm around 1900.