Earth Tide

Earth tide or body tide is the small (<1 metre) motion of the Earth's surface at periods of about 12 hours and longer. The motion is caused by the gravity of the Moon and Sun. The largest body tide constituents are semi-diurnal, but there are also significant diurnal, semi-annual, and fortnightly contributions. Though the gravitational forcing causing earth tides and ocean tides is the same, the responses are quite different.

Read more about Earth Tide:  Tidal Forcing, Body Tide, Other Earth Tide Contributors, Tidal Constituents, Earth Tide Effects

Famous quotes containing the words earth and/or tide:

    Words whispered on Earth are heard in Heaven like thunder; evil done in dark places the gods see like lightning.
    Chinese proverb.

    Where have you gone? The tide is over you,
    The turn of midnight water’s over you,
    As Time is over you, and mystery,
    And memory, the flood that does not flow.
    Kenneth Slessor (1901–1971)