How would you describe Earth’s shape? Most would say it is round or shaped like a ball. But experts describe its shape as a “lumpy potato.” It is flatter at the poles and wider in the middle. Earth is also “lumpy,” so different parts of the planet have different amounts of mass [a measure the amount of matter]. The more mass an object has, the stronger its pull of gravity [a force that pulls objects toward each other]. Earth’s gravity is the force that pulls objects towards its center. Due to the differences in mass, the pull of gravity is different across the planet.
Scientists have also discovered something interesting. There is an area in the Indian Ocean, where gravity is much weaker than normal. They have called this a “gravity hole.” In this area, the pull of gravity is weak. The weak gravity has even caused the level of the ocean water to be less in that area!
Scientists have known about the gravity hole for over 70 years. But they did not know what caused it. Because of computer models, they may now have an answer. Earth’s land and oceans are always in motion. Over time big changes have happened. Scientists think that an ocean may have been pushed deep inside the Earth, causing the hole. They think the hole formed about 20 million years ago.
What Do You Think? Why do you think the scientists used computer models?
Photo Credit: (t)NOAA/NGDC, (b)Bazava/123RF
