the greater the earth at the equator. The fact was revealed from studies of data collectedby the satellite Gravity Recovery and Climate Experiment (GRACE) belonging to NASAand the German Space Agency. Mentioned, the increased accumulation at the equator is caused by the melting of ice sheets in Greenland and Antarctica.
According to Steve Nerem, scientists from the University of Colorado, United States, up to 22 thousand years ago, ice up to several kilometers blanketed most of the northern hemisphere of Earth. Due to pressure from the weight of ice on land has been reduced due to melting, the ground beneath him was bouncing and causing Earth to become more oval. ”Similar to a sponge, and it takes a long time that the Earth back to the original form,” says Nerem.
For information, early on, planet Earth is not perfectly round. Due to the velocity of rotation, the water in the Earth’s surface more clustered in the equatorial region than at the poles.
The scientists themselves to observe the occurrence of “shrinking the fat” on the circumference of the equator. But then there is a change. Around the mid-1990s, it is known that the trend has reversed and Earth re-added “fat in waist circumference,” just like a ball which is pressed from above and below it. But they do not have the tools to determine why it happened, until recently.
With GRACE, researchers can test the theory that ice loss is altering the form factor of planet Earth. GRACE take pictures of the Earth’s surface every 30 days, allowing researchers to monitor changes in ice mass to changes in gravity. So, if there are changes to the shape of Earth, then there will be changes to the mass distribution.Consequently, the gravitational field is also changing.
Researchers found that the melting glaciers in Greenland and South Pole are the largest contributor to the swelling of the “waist” of Earth as much water is brought to the equator. According to the data, the two hemispheres of the Earth loses 382 billion tons of ice per year. Reduced burden that needs to be borne by the continent allows the soil to rise and make the planet a more rounded, but this process takes thousands of years.Meanwhile, growth in thickness at the equator reaches 0.7 centimeters per decade.
Currently, said Nerem, 21 kilometers radius of the planet Earth at the equator is greater than at the poles. That is, the surface of the Earth’s farthest point from Earth’s core is not at the peak of Mount Everest, but on top of a volcano in Ecuador that is closer to the equator.