The geographical poles—the north and south tips of the axis
that the Earth spins around—wobble over time due to small variations in the
sun’s and moon’s pulls, and potentially to motion in Earth’s core and mantle.
But changes on the planet’s surface can alter the poles, too. They wobble with
every season as the distribution of snow and rain change, and over long stretches
as well. Roughly 10,000 years ago, for example, Earth woke up from a deep
freeze and the massive ice sheets sitting atop what is now Canada melted. As
ice mass fled, and the depressed crust rebounded, the distribution of the
planet’s mass changed and the north pole started to drift west. This pattern
can be clearly seen in data from 1899 onward. But a recent zigzag in the north
pole’s path (and the opposite movement in the south pole) suggests a new change
is afoot.
Read the Scientific
American story - “Earth Is Tipping Because of Climate Change.”
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