The NASA, through its Jet Propulsion Laboratory, has discovered that the Earth does not maintain a uniform rotation. Satellite studies reveal that the rotation speed of our planet experiences millimetric variations, as well as deviations from the Earth’s axis, a phenomenon known as polar wobble. This wobble involves the displacement of celestial poles in relation to geographic poles.
Although these changes are minimal, like milliseconds in the duration of the day, they highlight the impact of natural factors and climate change. Human activity, along with the redistribution of water, is significantly influencing these phenomena.
Key Factors in the Earth’s Rotation according to NASA
NASA has identified three main forces that influence Earth’s rotation. The first is the melting of the poles. The accelerated melting of glaciers in Greenland and Antarctica releases massive amounts of water into the oceans, displacing mass towards the equator and slowing the planet’s rotation.
Another factor is atmospheric friction. Phenomena like El Niño alter wind and pressure patterns, affecting Earth’s rotation speed. According to David Salstein, a NASA-funded researcher, atmospheric variations, especially changes in jet streams, can account for up to 90% of short-term fluctuations in the length of the day.
Finally, the dynamics of the Earth’s core also play a crucial role. Tidal friction generated by the Moon’s gravitational pull decreases Earth’s rotation at a rate of 1.5 to two milliseconds per century. Additionally, the fluid movements of the outer core redistribute rotational energy.
These elements, combined with the loss of groundwater and the rise of sea levels, affect the planet’s mass distribution. When this mass shifts towards the equator, Earth reduces its spin speed.
