Global warming and the Earth's axis

                                                                                            Shutterstock

 

Most people would be aware that the Earth's rotational axis is not steady but tends to wobble as the planet is not a perfect unchanging sphere. Due to plate tectonics, erosion, weather masses moving around the surface, large ice masses weighting down sections of land, the poles actually move and this drift averages around 6 centimetres a year. This movement for example drew the North Pole towards Labrador in a Southerly direction.  For compass users, this situation will be familiar due to the adjustment calculation needed for grid to magnetic measurement to compensate for the drift when navigating using maps.

However in 2005 this drift suddenly altered and shifted to an Easterly direction and accelerated corresponding to an increase in the melt occuring in Greenland and Antarctica. Researchers at the University of Texas in Austin found using the GRACE (Gravity Recovery and Climate Experiment) satellites that around 600 gigatonnes of mass was being lost each year by the large glaciers in Greenland, Antarctica and the mountain glaciers. This mount of water being released from the glaciers into the oceans accounted for 90 % of the polar drift since 2005.  In short the planet's tilt was unexpectedly altered due to the effect of climate change.