Ocean Tides and the Earth's Rotation (2001)
4 days ago
- #Geophysics
- #Tidal Effects
- #Earth Rotation
- Tides affect Earth's rotation in two ways: slow secular changes and rapid, periodic changes.
- Secular changes increase the length of day by about 2.3 milliseconds per century due to tidal friction.
- Rapid changes in rotation occur at tidal periods (e.g., half-daily, daily) and are measured by modern techniques.
- Tidal braking is primarily caused by ocean friction, with mechanisms like bottom friction and wave breaking.
- Ocean tides change Earth's moment of inertia and exchange angular momentum with the solid Earth, affecting rotation.
- Long-period tides (9 days to 18.6 years) also influence rotation, with solid-earth tides being dominant.
- Historical and modern studies, like those by Munk and MacDonald, form the foundation of understanding Earth's rotation variations.