Ancient Seas Reveal Major Shifts in Earth’s Orientation

Seas that vanished millions of years ago have offered scientists evidence that Earth repeatedly reoriented itself relative to its axis of rotation.

Rather than relying on the “fossil compasses” preserved in rocks, the researchers traced ancient seas to look for signs of these large-scale shifts.

Their investigation identified a signature suggesting that Earth’s orientation changed more than once in its distant past. The findings point to a history of repeated reorientation rather than a single isolated event.

The approach offers a different way to investigate planetary movements, drawing on the record of long-disappeared seas instead of the magnetic clues locked inside rocks.