Melting ice sheets and changes in water storage is changing the Earth's rotation, a new study has found.
In the past, experts have considered the melting of Greenland's ice sheet as a strong factor in Earth's rotation shift. However, in a new study by NASA, experts have also included Antarctica's melting ice sheets and modifications in the planet's hydrology.
While the Earth continues to move in its axis from west to east and performs its duties of rotating every 24 hours, experts found that the axis itself is moving. This means that the North and South Poles also changing, with recent reports saying that the North Pole is presently moving to the United Kingdom.
The Earth's Rotation
The imaginary yet all-important axis of the Earth's rotation has never stayed in the exact same location. This is because the objects moving inside the planet influence subtle shifts in the axis.
As mass is distributed within a rotating object like the Earth, the way it spins also changes. Think figure skater whose spin changes with various flicks of the arms or extensions of the legs.
In the case of the planet, losing a vast amount of mass on one part may trigger the pole to move towards that direction. That is somehow the law of nature.
Experts have monitored these movements for the past 115 years. They found that until the year 2000, the North Pole was shifting towards Canada and the South Pole, making corresponding shifts as well.
In the latest observations, the North Pole is now gearing toward Europe and the motion has also increased.
Melting Ice Sheets
Melting ice sheets have been a popular factor attributed to the shift of the Earth's rotation. Climate change and the subsequent loss of mass in one part of the Earth causes poles to move and rotation to change directions. Even the loss of small glaciers in some parts of the world is said to play a part.
There are many factors associated melting ice sheets. Recently, a new study suggests that the melting of Greenland's ice sheet may be attributed to warm and moist air.
NASA has found that Greenland is depleting about 287 billion metric tons of ice annually, while Antarctica, 134 billion metric tons.
World Water Storage
Experts also found that polar shift may be influenced by how much water continents contain. Study author Surendra Adhikari explains that different locations store varied amounts of water because some experience more precipitation or droughts than others. Such happening contributes significantly to the changes in the overall shift of the polar motion.
Bright Future For Monitoring Earth's Rotation
Study author Erik Ivins says it is possible to use the same technique of polar motion assessment in future researches that aim to identify if Greenland had experienced any mass changes from 1899 to present that is similar to the current situation.
"This newly discovered link between polar motion and global-scale terrestrial water storage variability has broad implications for the study of past and future climate," the authors write.
The study was published in the journal Science Advances on April 8.