NASA scientists have discovered the secret of displacement of the Earth’s axis

© NASA/JPL-CaltechНаправление «migrations» of the Earth’s axis (blue line) and their «perpetrators» of the processes in the hydrosphere (dark blue), retreat of glaciers (orange) and processes in the mantle (red)NASA scientists have discovered the secret of displacement of the Earth’s axis© NASA/JPL-CaltechПодпишись to daily updates RIA Science

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Small shifts of the Earth’s axis, discovered several decades ago, were associated not only with the end of glaciation, but also the flow of the mantle and redistribution of the mass of water in the oceans. To such conclusion the head of NASA, published a paper in the journal Earth and Planetary Science Letters.

«Traditionally, only the end of the ice age was the main cause of the recent displacements of the Earth’s axis. We have created a computer model of this process and found that there is not one, but three sets of factors,» said Surendra Adhikari (Adhikari Surendra) from the jet propulsion Laboratory of NASA in Pasadena (USA).

Earth, unlike most of the planets of the Solar system, has a relatively stable axis. Due to the gravitational interactions of our planet and the moon, the position of the axis was not changed in the past few billion years, whereas the axis of Mars, Uranus and major moons of the giant planets shifted by tens of degrees.

Nevertheless, as observations show the end of the last century, the Earth’s axis is still a little, but shifted about ten centimeters per year in the direction of 74 degrees West latitude. Many scientists believe that this is due to the completion of the ice age and changes in the structure of the ice cap. However, others note that such processes are clearly insufficient for explaining the current rate of displacement.

Adhikari and his colleagues created a computer model of the Earth, taking into account how various processes in the lithosphere and the hydrosphere affect the position of the axis, and found that the share of «heritage glaciation» accounts for only a third of all offsets.

Scientists drew attention to the fact that the distribution of matter within our planet depends not only on how hard the surface pushes the ice cap and where it is located, but also how to move the flow of mantle in the deep layers of the subsoil, and the distribution of water in oceans, rivers and soil.

By combining seismic data measurements, climate satellites and other observing systems working of mineral resources, geologists have calculated the impact of these factors on the movement axis. To their surprise, it turned out that the influence is approximately equal, and each of the factors explains the shifts by about a third.

In particular, scientists have found evidence that the soil drainage in the United States and India in the middle of the last century affected the position of the axis of the Earth is not less than the retreat of the ice North polar cap and melting of Greenland.

All of these processes, as noted by Adhikari should be considered when developing climate projections and assessment of how global warming and retreat of glaciers can affect the face of the planet and her life in the near future.

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