Earth polar wander and lunar contraction studies

Scientific research has identified significant geological shifts involving both Earth and the Moon. Studies published in the journal Science indicate that Earth is experiencing ‘true polar wander’, a process where the crust and mantle shift in relation to the core to maintain rotational balance. This movement is currently occurring at a rate of approximately ten centimeters per year, driven largely by mass redistribution from melting ice caps.

Geophysicists have identified four major episodes of this polar movement over the last 320 million years. Researchers are utilizing new methods, such as studying ancient sea-level changes, to distinguish this polar wander from standard tectonic plate movement.

In a separate finding, data from the Lunar Reconnaissance Orbiter shows that the Moon’s radius has decreased by about 45 meters over the last 400 to 800 million years. This contraction is caused by the cooling of the Moon’s interior, resulting in global adjustments to its single lithospheric plate, including moonquakes and the formation of young tectonic structures.